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Design of sub level caving method by means of mine model tests Sarin, Devinder Kumar 1970

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DESIGN OF SUB LEVEL CAVING METHOD BY MEANS OF MINE MODEL TESTS  By  DEVINDER KUMAR SARIN  B.  Tech.  (Hons).,  Indian  A THESIS  I n s t i t u t e of  SUBMITTED  Technology,  Kharagpur,  I n d i a , 1962  IN P A R T I A L FULFILMENT OF THE  REQUIREMENTS FOR THE DEGREE OF MASTER OF A P P L I E D SCIENCE  in the Department of MINERAL  We a c c e p t t h i s  ENGINEERING  t h e s i s as c o n f o r m i n g t o  the  required standard.  THE UNIVERSITY OF B R I T I S H COLUMBIA A p r i l , 1970.  I i  In  presenting  requirements British freely that  this for  an  Columbia, available  permission  scholarly  thesis  advanced I agree  for for  purposes  study.  I further  may  be  publication  copying  granted  representatives. of  this  without  my  by It  this  thesis  the  Head  of  The  University  V A N C O U V E R 8,  DATE:  APRIL,  of  British  Canada.  for  written  1970.  Columbia,  my  is understood  thesis  ENGINEERING  make  of  agree for Depart-  that  financial  gain  permission.  DEVINDER  MINERAL  i t  and  or  of  of  reference  copying  Department  University shall  extensive  allowed  the  the  Library  his  be  at  of  the  by  not  degree  fulfillment  that  ment o r  shall  in p a r t i a l  K.  SARIN.  ABSTRACT Design c r i t e r i a of ing,  as  i t would p a r t i c u l a r l y  means o f  geometrically Principles  due c o n s i d e r a t i o n flow  theories  of  to  involving  of  of  A total  of  various  orebody  in the stope  tests  that w i l l  Within  have  pressures,  etc.  in the  methods.  s c a l e model w e r e  Qualitative  t o be d e a l t w i t h  broken ore m a t e r i a l  have  conducted  observations  are  by t h e o r e t i c a l  accuracy,  the  re-  treat-  draw  i n t h e model a r e d e t e r m i n e d .  p a t t e r n s w h i c h w o u l d e n s u r e maximum o r e from the stopes  design of of  'blast  the s t o p e ,  Triaxial  Based  re-  h a v e been p r e s e n t e d  retreat  distance  1  for  d e p e n d i n g on  s u c h as m o i s t u r e c o n t e n t  compression t e s t i n g equipment.  flow properties  and  design of  stoping  and a d v a n c e d w o r k a r e  layouts  for  change  confining of  the  A remarkable  and h e n c e t h e draw c o n f i g u r a t i o n  R e c o m m e n d a t i o n s on f u r t h e r quantitative  with  Gravity  h a v e b e e n d e t e r m i n e d by m e a s u r i n g t h e f l o w p r o p e r t i e s  ore material with change  t e s t work  work.  Quantitative conditions  on a 1:30  reasonable experimental  c o v e r y w i t h minimum w a s t e d i l u t i o n  in natural  i n t h e model  design.  configurations.  mine l a y o u t  the mine development  min-  by  m a t e r i a l as a p p l i c a b l e t o t h e b i n d e s i g n w o r k  thirty-seven  the f l o w o f  on t h e s e f i g u r e s ,  use  the s i m p l i f y i n g a s s u m p t i o n s have been a n a l y s e d .  and t h e e f f e c t s  figures  C a v i n g method o f  t o G r a n d u c M i n e s , has been s t u d i e d  s i m i l a r i t y and t h e i r  granular  ment a r e d e s c r i b e d .  apply  Sub-Level  s c a l e d mine m o d e l s .  been u s e d w h e r e p o s s i b l e  ported  the L o n g i t u d i n a l  is  predicted.  i n c l u d e d on  t h e modern s u b - l e v e l  caving  the  ACKNOWLEDGEMENTS  The w r i t e r study  p r o g r a m and f o r Grateful  t h e management o f their  wishes  to  the a d v i c e  appreciation  encouragement  and a l s o h i s  The a u t h o r  is grateful  g u i d a n c e and c o n s t r u c t i v e this  L.  Emery  during  is expressed  for  this  for  guiding  the support  received  engineers  colleagues  in the e n g i n e e r i n g  thankfully  acknowledged.  c r i t i c i s m during  graduate  investigation.  Company and t h e s e n i o r  to P r o f e s s o r  his  C r o u c h and D r .  from for  department  Bain for  t h e d e v e l o p m e n t and  of  their  preparation  thesis. The o p p o r t u n i t y  essential  support  and d i s c i p i i n e .  April, 1970 STEWART,  are  C.  received  Granduc O p e r a t i n g  whose v a l u a b l e c o n t r i b u t i o n s  of  thank Dr.  B.  C.  received  is  taken here,  from h i s w i f e ,  as w e l l ,  to acknowledge  Sheshi, during  the  the p e r i o d of  study  V  TABLE OF CONTENTS PAGE CHAPTER  CHAPTER  1  INTRODUCTION  1  1.1  L o c a t i o n and G e o l o g y  1  1 .2  Purpose  1  1 .3  Scope  3  STATE OF THE ART  5  2.1  General  5  2.2  P r i n c i p l e s of  2  gravity  f l o w and d e s i g n  of  mass-flow bins 2.3  P r i n c i p l e s of granular  CHAPTER  similitude  in the flow  of  materials  12  THEORETICAL CONSIDERATIONS  15  3.1  General  15  3.2  Theory o f models  15  3.3  Gravity  3  f l o w and d e t e r m i n a t i o n s o f  parameters 3.4  CHAPTER  9  4  Design of  i n sub  level  mass-flow bins  the  caving v/s  19  stope d e s i g n . . . .  CONSTRUCTION AND OPERATION OF THE  33  TESTING  EQUIPMENT  36  4.1  General  37  4.2  Construction  37  4.3  Ore and w a s t e m a t e r i a l  40  4.4  Extraction  40  4.5  Operation of  4.6  Triaxial  drifts  and l o a d i n g b u c k e t  t h e model  compression t e s t i n g equipment  41 45  v i PAGE CHAPTER  5  TESTS DESCRIPTION  PROCEDURES AND RESULTS  5.1  General  5.2  D e s c r i p t i o n o f model  5.3  Test Program  5.4  Testing  5.5  Test  5.6  D i s c u s s i o n on t h e  49 49  tests  50 51  procedure  52  results  caving  56 longitudinal  sub  level  tests  58  5.61  20  ft.  orebody  width  58  5-62  30  ft.  orebody width  61  5.63  40 f t .  orebody  width  62  5.64  50  ft.  orebody  width  65  5-7  D i s c u s s i o n on t h e sub  level  Change  5.8  triaxial  caving  transverse tests  in the angle o f  68 siiding  -  determined  by  compression t e s t i n g equipment  CHAPTER  6  CONCLUSIONS  CHAPTER  7  RECOMMENDATIONS  69  72  FOR FURTHER WORK AND DISCUSSION  7.1  Recommendations f o r  f u t u r e work  7.2  Operational  7.3  Comments on t h e q u a n t i t a t i v e  and p r a c t i c a l  74  detail design of  74  76 the stopes  82  v i i PAGE  L I S T OF REFERENCES  APPENDIX  89  1 and IA -  Results  2, 3 and 4  the  recommended l a y o u t s  108  V  Pictures  APPENDIX  104  IV  Table 5 ~ Design data f o r  APPENDIX  96  til  Tables  APPENDIX  models  II  Tables  APPENDIX  84  I  Theory of  APPENDIX  ,  of  longitudinal  sub  level  c a v i n g model  tests  122  VI  Details  on G e o l o g y  131  NOMENCLATURE  <^  -  Ring  a^  "  Semi-major axis  A  -  Area of  -  Width of  bft  -  Semi-minor axis of  b.r.d.  -  Blast  B  -  Width o f  C  -  S i z e of  the e x t r a c t i o n  d  -  Average  s i z e of  dj  -  Digging  depth of  ds  -  Spherical  D  -  Diameter of  Dh  -  Hydraulic  A  w  vi i i  gradient  the  of  the e l l i p s o i d of  motion  the e l l i p s o i d of  motion  opening  si ice  retreat  distance  the e x t r a c t i o n  area  particles the  scoop  diameter of largest  or  drift  particles  lumps  perimetral  k x A / perimeter of of  in b l a s t e d  diameter =  orifice  ejvj  -  Eccentricity  Efg  -  Volume o f  the e l l i p s o i d o f  F.W.  -  Foot  T  -  Unit weight  g  -  A c c e l e r a t i o n of  h  -  Height  of  extraction  h'  -  Height  of  the g r a v i t y  h^  -  Height  of  the e l l i p s o i d of  H  -  Head o f  H.W.  -  Hang i ngwa11  K  -  Properties  the e l l i p s o i d of  motion  wal1 of  granular  of  material  gravity  p a c k i n g above  the  ore  drift flow motion  opening  lumpty  material  motion  Volume o f  discharge  A significant  distance  Any  distance  pertinent  Length Ore  scale  recovery = % ore  Width of  pillar  Angle of  internal  Blast  retreat  recovered  between  distance solids  Bulk density  of  packing  Swel1  interval  Natural Normal  solids  angle of stress  Horizontal  burden)  Angle of  side  (Angle of  Velocity  surface of  the hopper  bottom)  plane  = to ore b l a s t e d  discharge  volume  Volume o f  Volume o f  plane  on t h e v e r t i c a l  on f a i l u r e  loaded of  .  slopes  extraction rock  failure  i n c l i n a t i o n of  Shear s t r e s s  voids)  repose  stress stress  Draw  ring  'S')  + volume o f  on t h e  Vertical  % of  (or  or m u l t i p l e  factor  (Volume o f  Total  drifts  (single  of  level  blasted  friction  True d e n s i t y  Sub  to ore  container  (100%)  from opening  sliding  sol  Volume o f Average  discharged  vertical  S p e c i f i c weight  Waste d i 1 u t i o n % of waste Depth b e l o w  pressure of  (Dimensionally,  material  t h e m a t e r i a l o r dead  FL~3) =  loaded to t o t a l the  weight  surface  rock  loaded  (100%)  xi L I S T OF FIGURES FIGURE:  PAGE  1.  Gravity  flow of  2.  T r a n s v e r s e sub  3.  Longitudinal  k.  Failure  granular level  sub  material  8  caving  level  20  caving  in c o h e s i o n l e s s  21  granular  material  p r e c e d e d by a r c h i n g transverse  30  5.  Standard  6A.  M i n e Model  6B.  M i n e Model a s s e m b l e d f o r  7.  Blast  wooden  drift  9-  C a l c u l a t i o n procedure  by  longitudinal  level  sub  level  Comparison of  12.  Longitudinal  caving  38,  for  ore sub  k~J ore  recovery,  and w a s t e d i l u t i o n  57  moisture content  recoveries level  caving  v/s  total  extractions  easer holes  80  sub  level  caving  -  vee shaped  ]k.  Longitudinal  sub  level  caving  -  shows  drift sub  on e a c h s u c c e s s i v e level  two e x t r a c t i o n  6k  -  Longitudinal  Longitudinal  determined 70  p o s i t i o n i n g of  with single  39  block,  13.  with  37  test  11.  15.  caving  kl  s l i d i n g with varying  triaxial  possible  sub  3k  t e s t i n g equipment  extraction  Angle of  layout  and b u c k e t  Triaxial  10.  caving  transverse  blasting  8.  total  level  assembled f o r  plates;  extraction  sub  caving  drifts  -  on a s u b  sequence o f sub  shows  long hole  81  draw  level  sequence of  level  fans  123  to  127  128  to  130  draw  xi i  L I S T OF  TABLES  TABLE:  PAGE  1.  Longitudinal  IA.  T r a n s v e r s e Sub L e v e l  2.  3.  "Results of  Sub L e v e l  Triaxial  Sieve analysis  in the T r i a x i a l  k.  Ore m a t e r i a l  5.  Summary  the  -  of  Caving  Caving..  Compression Tests  samples  102  103  105  106  i n t h e model  Design data  to  used  Tests  used  97  107  for  recommended l a y o u t s  109  6.  Test No.  33;  L o a d i n g Sequence  121  7.  T e s t No.  32;  Loading Sequence  121  CHAPTER  1  1  *  INTRODUCTION  1. 1  L o c a t i o n and  Geology:  The G r a n d u c M i n e rugged mountainous Access to Tide mine.  to  country,  the  about  The  t h e mine f r o m S t e w a r t  Concentrator  deposit  is  Columbia of  Alaska  Stewart,  i s made by means o f  1/4  mile  located at Tide  long tunnel  boundry  in  B.C.  a 32 m i l e  road  connects with  L a k e Camp and t h e  the  townsite  is  Stewart.  Forty-three are  British  36 m i l e s N o r t h w e s t  L a k e Camp, f r o m w h e r e an 11  s i t u a t e d at  tion,  is near  reported  m i l l i o n tons of o r e , t o have been  averaging  Mineralization  copper  i n d i c a t e d by d i a m o n d d r i l l i n g  i s c l a s s i f i e d as M e s o t h e r m a l R e p l a c e m e n t .  f o l d e d and f a u l t e d  1.73%  consists  e s s e n t i a l l y of  pyrrhotite,  dilu-  (1966) .  The o r e b o d i e s  s i l i c e o u s m e t a s e d i m e n t s c u t by f e l d s p a r  before  occur  porphyry  chalcopyrite,  The in  dikes.  pyrite  and  sphalerite."  1 .2  Purpose: This  thesis  is concerned with  Level  caving method, p a r t i c u l a r l y  level  caving, with  The p r i n c i p l e s bodies  with  for  of  Longitudinal  to the Granduc M i n e s .  SubSub-  (7,500  m i n i n g the Granduc tons/day)  and low  good m i n i n g p r a c t i c e s , w h i c h  orecost, include  maximum r e c o v e r y and minimum d i l u t i o n .  the  transverse  is  l o n g h o l e b l a s t e d , whereas  VI  the  has b e e n c h o s e n as t h e m i n i n g m e t h o d .  productivity  In  * See A p p e n d i x  respect  d e t e r m i n i n g t h e b e s t method f o r  the a c c e p t a b l e premise of  the d e s i r a b i l i t y  the ore  with  t r a c k l e s s equipment,  h a v e b e e n b a s e d on h i g h  together  the design of  for  as w e l l  detailed  as  in the  longitudinal  the waste  geology.  is caved.  sub-level  caving,  Test d r i f t s  driven  2. into  the hanging w a l l ,  gree of cave.  which  cross-fracturing Furthermore,  which  portions  where between f i f t y by t h e t r a n s v e r s e This  a major  contact.  In  easily  f r a g m e n t a b l e and  fault within the worst  of  the orebody,  ten to  case,  liable  twenty  to  feet  i n d u c e d c a v i n g may  sub-level  c a v i n g method  has b e e n p r i m a r i l y on t h e  the o r e b o d i e s  the whole; t i e d up  Mines  these areas.  the  which c a l l  Therefore,  Longitudinal  to Hanging w a l l  the c o n s u l t a n t s  from f i f t e e n total  planning of this  field  sub-level  establish tance of  transverse  relatively  in t h i s  case.  sub-level  (retreat  they serve  tests,  locally  as a c o n s t a n t  The p r i n c i p a l  A l s o the presence at  slides  and o t h e r  useful  for  the  wings  performed,  is  further  reference  the mine o f  for  permanent  aids developed during  t r a i n i n g of  was  than  the  Granduc  i s needed f o r  the mine p e r s o n n e l  of  strike)  reason being  that  the  min-  Preliminary  taken up.  The  e m p h a s i z e d by  :  since  of  the course of from time to  the  fact  layout  pictures, testing,  time.  to  impor-  m i n e p l a n n i n g and records  on  are  r e s e a r c h w o r k was n e e d e d  study  as  feet  n o t w i t h much e x a c t i t u d e ,  Further  hence t h i s  source of  work.  visual  The  a l o n g the  s t o p e s c o u l d be u s e d .  unexplored.  t h e optimum l a y o u t s , these  as w e l l  to f i f t y  became i m p e r a t i v e f o r  c a v i n g method  t h e s e a r e a s has b e e n done b u t is  retreat).  mineable tonnages  t h e same e q u i p m e n t and t h e b a s i c d e v e l o p m e n t w o r k as adjacent  t o be m i n e d  f o r m i n i n g methods o t h e r  it  any-  p r o g r a m t o d e t e r m i n e t h e b e s t method o f m i n i n g  c o n s i d e r e d most s u i t a b l e  ing of  are planned  i n Canada and a b r o a d .  in widths  more t h a n 50% o f  caving.  to conduct a study  (Footwall  obtained elsewhere  in these narrow w i d t h s , sub-level  feet,  recommendations o f  a r e narrow and v a r y  approximately  transverse  w h i c h a r e d e f i n e d h e r e as  and o n e h u n d r e d and t w e n t y  on some f i e l d e x p e r i e n c e  is  it  required. The w i d e r  of  i n t h e s e d i m e n t s , shows a m a r k e d d e -  renders  there occurs  away f r o m t h e h a n g i n g w a l l be  is mainly  are  3.  Scope:  1.3  A 1:30  s c a l e m i n e model was c o n s t r u c t e d  w e r e c o n d u c t e d on a c a r e f u l l y production study  of  drifts/draw  the "cave  in the s t o p e s .  d r a w n up t e s t  p o i n t s on p r o p e r  figures" or  Therefore,  ore  sub-level  (a.)  interval  d e p e n d s on  motion" of  The  of  the  the broken to s i z e  the  rock  for  the  t e s t i n g was d i v i d e d  in-  study:  The  first  figures  series of  t e s t s were c a r r i e d out  w h i c h have a l r e a d y  the t r a n s v e r s e bodies.  This  sub-level  been u s e d f o r  has a s p e c i a l  some o p e r a t i o n a l  experience  The s e c o n d s e r i e s o f sub-level  importance,  nages.  in programing  This  importance of  helped  these a r e a s .  Tests  the  drifts  and f o o t w a l 1  as  date.  longitudinal  a n g l e s and in order  r e p r e s e n t i n g orebody  slash,  of  Geological  t e s t work  interval,  of tonof  widths  f o o t w a l 1 a n g l e s and  i n p a r a m e t e r s s u c h as s u b - l e v e l  i n deta i1.  performances  the  a s s o c i a t e d footwal1  20', 30', **0', and 50' a t v a r i o u s  extraction  a comparison  the a c t u a l  of  ore-  a t a b l e was p r e p a r e d w h i c h showed t h e w i d t h s their  change  for  the help of  the o r e b o d i e s , w i t h  of  the wider  is o b t a i n e d at a l a t e r  With  the  the p l a n n i n g work  t e s t s w e r e p e r f o r m e d on t h e  caving method.  Department,  to check  c a v i n g methods f o r  t h e model w o r k c o u l d be made w i t h  (b.)  tests  Optimum l a y o u t  from the mine crushed  model w o r k was u s e d t o d e t e r m i n e t h e s e f i g u r e s . t o two a r e a s o f  t h e p r o p e r t y and  program.  the " e l l i p s o i d of  actual  at  location  e t c . , were c a r r i e d  with of out  Many p r e l i m i n a r y  t e s t s were needed b e f o r e a s a t i s f a c t o r y  c e d u r e c o u l d be d e v e l o p e d . has b e e n  included Additional  ties  of  A d i s c u s s i o n on some o f  in Chapters  t e s t i n g was done t o d e t e r m i n e  t e s t i n g equipment.  Proposed mine l a y o u t s  7-  IV,  and s u g g e s t i o n s  The  encountered  the change  moisture contents  results  are  included  in flow  and a d v a n c e d w o r k a r e  proper-  by u s i n g a  Triaxial  i n C h a p t e r 5-  b a s e d on t h e t e s t w o r k a r e p r e s e n t e d  on f u r t h e r  pro  5.  the b r o k e n o r e o v e r a range of  Compression  dix  3 and  the problems  testing  included  in Appenin  Chapter  5. 2  CHAPTER S T A T E OF  2.1  earliest  caving  caving  in s p i t e of  regarded  as  the  ment and  long-hole  advent  of  sidered  and  method  i s now  column next  ing  the  often  of  ore  drawn w i t h  of  one  recovery  last  ten  out  studies  conducted  introducing  parable  to  possible. that  a  strict  block  each the  or  so  a  natural  layouts  been  a  ferrous i t can  a  with  a  be  with  readily  large  proportion  or  large  of  caving,  caved  waste  on  other  considerable in the  on  the  recovery carefully  control  i n any  amount o f  form  conditions.  as  of  This  draw  the  is e s s e n t i a l to  the  in that  the  method. has  been  shown and a  cave  success  that  method  of  of by  employing  dilution  metal  of  Dur-  t e s t s and  has  e s p e c i a l l y in base  stoping.  the  characteristics  controlled block  the  sides,  scale-model  with  develop-  wall  research  in conjunction  in  solid  other  research  and  down and  sub-level  a l l the  the  i t is  the  costs  sub-level  great  and  selectivity  by  as  develop-  large, thick  problems,  keeping  was  i n c r e a s i n g l y con-  i s bounded  are  i t  mechanized,  to  was  ground  recovery,  mechanized  is being  fewer  of  low  blast  indicated,however,  p o s i t i v e draw  incompetent  b l a s t i n g techniques  mines  caving  extracting  fan  based good  With  method  presents  c o u n t r i e s , both  obtained  I t has  to  dilution  techniques,  that  this  and  relatively  improved  characteristic  and  and  under  improved  mining  side  years  i n many  weak  factors a l l contribute  preferred  b l a s t i n g and  available.  i s p o s s i b l e and  inherent  carried  modern  equipment  the  on  and  is because  to  fan  problems  These  and  equipment,  This  orebodies  in ore.  Due  the  method  in base metal  orebodies.  of  i n mines w i t h dilution  practical  standardization of  is  high  drilling  applied  variable-grade  thin  only  a  used  patterns  trackless extraction units,  competent safe,  in various  method  conditions;  ment  ART  General : Sub-level  the  THE  is  ores, the  com-  6. method.  The  term  'positive'  in t h i s  context  draw g r a d e and e x t r a c t i o n  tons  and a l s o  r e c o v e r y and d i l u t i o n  2.11  to gain  reliable  record  means o b t a i n i n g a c o m p r e h e n s i v e  Theory of  Sub-Level  Cave  So f a r  is  the b u l k of  as  known,  I n s t i t u t e of principles  Technology,  the d e s i r e d  in each  point  drawpoint.  research  sub-level  into  the s u b - l e v e l  in p a r t i c u l a r ,  J a n e l i d and K v a p i l ' s caving  is  probably  caving  by  the  Royal  p a p e r on  (^7)  t h e most  the  authoritative  date. Model  c a r r i e d out Mines,  experiments  i n Sweden a t  It  Shape o f  rock,  point  flows  drawn f l o w s disturbes fifteen  it  t o expound  those  i n Zambia a t M u f u l i r a  that  all  Copper Craigmont  the c h a r a c t e r i s t i c s  have a major  involved  i n f l u e n c e on t h e  on t h e u n d e r s t a n d i n g o f  h a s been f o u n d  pressure,  granular  from a zone  obeys  material  a larger  that  zone,  the s i z e of  the g r a v i t y  t h e same l a w s and in a bunker.  in the shape o f  f r o m what J a n e l i d  times  been  it,  are  method  described.  Draw:  under  to the flow of  but  and t h e r e f o r e ,  Basically, caved  Isa M i n e s ,  a r e known t o h a v e  Mine.  c a v i n g draw,  draw c o n t r o l ,  studies  K i r u n a and M a l m b e r g e t M i n e s , a n d i n Canada a t  is not p o s s i b l e here  in s u b - l e v e l  2.12  and u n d e r g r o u n d  i n A u s t r a l i a a t Mount  M i n e s and F r o o d S t o b i e  of  figures  i n Sweden a n d ,  Stockholm.  and t h e o r y o f  t h e draw a t  Draw:  m i n i n g method has been c a r r i e d o u t  to  to stop  calls  c a l l e d the  the  flow of  blasted  is approximately  similar  Broken rock e n t e r i n g a draw-  an e l l i p s o i d .  The a c t u a l  ground  ' e l l i p s o i d of m o t i o n ' . T h i s ,  ' l i m i t e l l i p s o i d , which  the e l l i p s o i d of  or  1  motion  (see  Fig.  is 1A).  in  turn,  approximately If  the  material  b e i n g drawn c o n s i s t e d o f  be v i e w e d  through  a cone w i t h Fig.  a glass  the apex at  plate,  laminations of  different  t h e draw w o u l d a p p e a r  the drawpoint  and t h e s i d e s  colours,  and  t o be i n t h e f o r m o f  slightly  concave  (see  IB). In  Fig.  IE.  this  be made b e t w e e n  its  semi-major axis  The v o l u m e o f to that  of  (Fig.  be d e s c r i b e d EN If  a ^ and  the e l l i p s o i d of  IC).  its  the  Distinction  semi-minor axis  m o t i o n E^ (Fig.  Therefore,  i s m a r k e d E^.  ID)  approximately  OO  K  N  ^  b^. corresponds  and t o the volume o f  the  dis-  r e l a t i o n s h i p between t h e s e can  thus  2 (.1)  VN  t h e v o l u m e V^ a n d t h e h e i g h t  N  of /  V  Fig.  the e l l i p s o i d of motion a r e  IE c a n be c a l c u l a t e d f r o m t h e  formula:  2 (2) N  The c h a r a c t e r i s t i c s o f d e t e r m i n e d by  of  N  2.094 h  its eccentricity  the shape of  the e l l i p s o i d of motion  are  e^  where  2  eN  The IE.  can  by:  the s e m i - m i n o r a x i s b  e l l i p s o i d of motion  the d i s c h a r g e d m a t e r i a l  charge cone  Fig.  could  ( a  t e r m s a ^ and b^  N  2 -  in e q u a t i o n 2  b  (3)  N  2 (3)  )  correspond  to  those  of  known,  8.  FIG. IA GROUND UNDER PRESSURE IS DRAWN FROM A ZONE IN THE FORM OF AN ELONGATED ELLIPSOID,TERMED THE ELLIPSOID OF MOTION'. THIS DISTURBS THE GROUND IN A LARGER ZONE, TERMED THE LIMIT ELLIPSOID, FROM JANELID KVAPIL  FIG. IB RELATIONSHIP BETWEEN VISIBLE DRAW CONE AND ELLIPSOID OF MOTION AND LIMIT ELLIPSOID. MATERIAL DRAWN FROM B IS REPLACED BY MATERIAL GRAVITATING FROM AREAS A AND C. FROM JANELID AND KVAPIL. Limit ellipsoid  Limit ellipsoid  Ellipsoid of motion  Ellipsoid of motion  Draw cone  FIG. IC  FIG. ID  FORM OF ELLIPSOID OF MOTION AS A FUNCTION OF PARTICLE SIZE  FIG.I. GRAVITY FLOW OF GRANULAR MATERIAL  FIG. IE  ELLIPSOID OF MOTION CUT OFF BY THE BUNK£R WALL  9. The c h a r a c t e r i s t i c s its of  eccentricity,  are not  the shape o f  constant,  the m a t e r i a l . S m a l l e r p a r t i c l e s  soid of  m o t i o n and t o a g r e a t e r  ellipsoid  in width  and  matically  in  1 (F,  For tors  s u c h as  opening  faster  laws  increases  others Level  2.2  design of  becomes  the e c c e n t r i c i t y ) ,  increases  but  foregoing  to a slimmer  Larger  particles  less.  This  is  extend  shown  size  ellipthe  sche-  d e p e n d s on a number o f (enlargement of  fully if  flow of  principles  flow  is  discharge motion  discharge  to  Fig.  material  prevented  (a  lies  not  do  for  the v e r t i c a l  not  var-  axis.  in the  centre  li).  h a v e been u s e d by J a n e l i d  the parameters of  fac-  etc.  the d i s c h a r g e opening (see  of  granular  and s y m m e t r i c a l l y  in the s i d e w a l l  the  the e l l i p s o i d of  the e c c e n t r i c i t y ) , gravity  of  the v e l o c i t y  e v e n when t h e g r a v i t y  for- example,  in determining Caving  correspond  the height  in connection with  the bunker bottom,  i.e.,  H).  from d e v e l o p i n g  Such c a s e s a r i s e ,  The  material  eccentricity.  the e c c e n t r i c i t y ) ,  discharge  motion,  d e p e n d v e r y much on t h e p a r t i c l e  the d i s c h a r g e o p e n i n g  any b a s i c c h a n g e s ,  reasons  of  eccentricity  G,  the s i z e of  rate of  undergo  its  but  the e l l i p s o i d o f  t h e same m a t e r i a l , t h e e c c e n t r i c i t y  height  The  ious  Figs.  increases  (a g r e a t e r  of  of  particularly  and K v a p i l  the Transverse  and  Sub-  method.  P r i n c i p l e s of  Gravity  F l o w and D e s i g n o f  Principles  of  gravity  f l o w h a v e been a p p l i e d  the bins  for  reviewed w i t h  the  intent  these are mentioned Since  some t i m e now. of  studying  Mass-Flow  Many r e f e r e n c e s applications  Bins:  in the  quantitative  on t h e s u b j e c t  in stope design.  were  Some o f  here.  the c l a s s i c a l work o f  J a m i e s o n on t h e g r a v i t y  flow of  Janssen  grains  (44),  in e l e v a t o r s  Ketchum  (43)  and  and b u l k s o l i d s  in  bins,  10. several  writers  have d i s c u s s e d t h i s  Bernache  ( 1 5 ) , M r o z and D r e s c h e r  (22,  24), Handley  23,  Johnson  (7,  8,  a r e on r e c o r d ,  9),  and P e r r y  Walker  (10,  more t h a n 200  problem.  (16),  Roberts  (31), 11)  For example -  Jenike  (17),  1,  and o t h e r s .  selected  Peschl  (19),  3,  4, 5,  At  the present  references  6,  Kvapil  36,  (13,  Aytaman 37,  38),  time,  on t h e s u b j e c t  14),  of  there  Flow  of  Granular Materi als . However, application  of  by  far  the p r i n c i p l e s of  made by J e n i k e ,  Johnson  of  all  the works of  authors  the w r i t e r s  development of  as O r e s ,  out  this at  at  contributions  flow  Therefore, this  Soil  (3),  It  is well  flow properties  of  solids  distribution, etc.,  c a l c u l a t i o n of  critical  A direct-shear, measuring  unit.  for  1953,  gravity  i n t o any the  last  most o f  flow of  by J e n i k e  been  detail three  the Utah  is  concepts  t h e w o r k was of  such  (37),  W h i l e the  dimensions of  carried  Engineering  instance,  of  lowest  of  various  due t o c h a n g e s angle of  solids  have  been  the hopper w a l l s  from the works of  shape, bulk d e n s i t y ,  The c o n d i t i o n s  has  Utah.  known now, vary,  bins,  the  here.  (1957 - 1962),  then the c r i t i c a l  be d e t e r m i n e d .  temperature,  only  has s t a t e d t h a t o n c e f l o w p r o p e r t i e s  m e a s u r e d and a r e k n o w n ,  size  going  M e c h a n i c s and P l a s t i c i t y .  S t a t i o n , University of  Jenike  without  C o a l and C h e m i c a l s , e t c . ,  Flow L a b o r a t o r y  to the study of  the d e s i g n o f  s t a g e , works of  f o r m u l a t e d by h i m i n  the b u l k s o l i d s  in  a mathematical theory of  Concentrates,  t h e o r y were  Experiment  tent,  gravity  and W a l k e r .  b a s e d on t h e c o n c e p t s o f of  important  m e n t i o n e d above have been d i s c u s s e d The  solids  t h e most  have  that  in moisture  internal  flowability  authors,  can  con-  friction  t o be u s e d  and in  the  dimensions. constant  Specimens o f  the  rate of  s t r a i n m a c h i n e i s e m p l o y e d as a  tested s o l i d are f i r s t  consolidated  within  ] 1. the shear  cell  ing pressure ciple  and t h e  resultant  flow properties  tester wall  and t h e n s h e a r e d t o o b t a i n a r e l a t i o n  a l s o measures  of  tests  of  the bulk s o l i d s ,  the angle of  m a t e r i a l s as w e l l  ability  strength  as o t h e r  the s o l i d . namely,  friction  properties  c a n be c a r r i e d o u t  for  e n c e d by C e n t r a l wet  fine  coal  (10,  11)  adopted  to o b t a i n  to d e r i v e flowing (12),  the approximate s t r e s s e s  Flow-  ment b e t w e e n t h e  the d i r e c t  is  built  w o u l d be u s e f u l flow or  motion whenever  any o f  bin,  some c h a n n e l  in which  the  to  1961  (11),  England,  and c h u t e s ,  tests  his of  the  Jenike,  experi-  in  1967.  getting Most  The  of  approach  similar  has s i m p l i f i e d t h e  use o f  gravity.  etc.  is b a s i c a l l y  to  calculation  a g r a n u l a r material  ring  shear  has p r o v e d  tester  more  agree-  design.  h a v e been c a r r i e d o u t on h o p p e r s Material  is  plug it  to d e f i n e h e r e , flow.  two  t e s t e d and a  types  i s drawn o u t .  (dead)  flow channel  coincides with  the bin  loadings  are a l s o well  flow  all  In a f u n n e l - f l o w  by n o n - f l o w i n g  bin  of  In m a s s - f l o w b i n s ,  surrounded  d e f i n e d and c o n s t a n t ,  be h a n d l e d by  through  flow  deter-  de-  container  the m a s s - f l o w .  f l o w and f u n n e l  within  tester  and W a l k e r ' s m e t h o d .  that ensures It  shear  c a s e , model  s i g n e d by J e n i k e ' s  moisture content,  that would occur w i t h i n  t h e o r y and t h e p r a c t i c a l  In e i t h e r  flow.  can s t i l l  bunker  in a bunker and has c l a i m e d t h a t  The  in the design of  Board, B r i s t o l ,  However, Walker  prin-  used  the p e r i o d  the design data for  compared t o  the  the f l o w - f u n c t i o n .  the b u n k e r s , hoppers  between  t h a t a d o p t e d by J e n i k e .  This gives  of  a range of  Generating  through  h i s w o r k was c a r r i e d o u t  consolidat-  w o r k was s t i m u l a t e d by t h e d i f f i c u l t i e s  Electricity  to f l o w  the  between a s o l i d and samples  m i n e t h e maximum m o i s t u r e f o r w h i c h a s o l i d Walker's  between  patterns;  the s o l i d bin,  solid. itself  d e f i n e d and  flow  is  massin  occurs  In a m a s s - f l o w and, hence,  is  reproducible.  12. In a f u n n e l - f l o w , or  contract  content  it  as t h e f l o w  and  less  the m a s s - f l o w b i n s  unit of  i.e.,  expanded-flow  Longitudinal  of  a series of  Sub L e v e l  sections t e d by  of  culated pressures of  the  It  Caving  moisture  in f u n n e l - f l o w  i s made o f  a short serves  stress  pressures  s o l u t i o n of  mass-flow  to expand  of  that  from that of  a bin and,  c i p l e s ' of  quantitative  design of  A small  internal  the c o n d i t i o n s  different  Johnson  bins  results  rat Caving case  stresses  in o r d e r  Cal-  actually  during  and  find radio  flow.  caving  stope  to  sensitive  stope,  the a p p l i c a t i o n o f  t o be u s e d f o r  predic-  and W a l k e r .  pressure  in a s u b - l e v e l  therefore,  of  size  the hopper o u t l e t  is emphasized  developed.  the  converging  to the  a p p l i e s very near  the measurement o f  is c l e a r  in the  m a g n i t u d e , were o b t a i n e d as  region  hopper  bin.  sand  Jenike,  to  c a n make a s p e c i a l  has shown s i m i l a r i t y  in t h i s  be f u l l y  for  is  another  T r a n s v e r s e Sub L e v e l  under a f u n n e l - f l o w results  bins  In a d d i t i o n  (3) has d e s c r i b e d  f o r wide o r e - b o d i e s ,  t h e same o r d e r  mass-flow w i l l  was u s e d f o r  Jenike  the design of  close s i m i l a r i t y only  importance of  whether pill  The  that  hoppers,  t h e more r i g o r o u s  measured.  loading  varying  in m a s s - f l o w b i n s .  bins,  experimental  (31),  and 70°  65°  change w i t h  The m a s s - f l o w h o p p e r  m a s s - f l o w hoppers  Handley's  than  The c h a n n e l may e x p a n d  to a dimension which e l i m i n a t e s the p o s s i b i l i t y  c a n be a d d e d h e r e  or  solids  b i n s , where use bin.  itself.  As a r e s u l t ,  and f u n n e l - f l o w  the f l o w - c h a n n e l It  of  reproducible  under a f u n n e l - f l o w  holing.  the s o l i d  properties  and f r a g m e n t a t i o n , e t c .  more e r r a t i c  type,  forms w i t h i n  the  are  prin-  d e s i g n have  only  a 1imi t e d a p p l i c a t i o n .  P r i n c i p l e s of  2.3  Another ciples  of  Similitude  t o p i c of  in the  particular  s i m i l i t u d e so t h a t  Flow o f  interest  the behaviour  of  Grandular  to t h i s  Materials:  project,  a prototype  is  may be  the  prin-  correctly  13. predicted  from the o b s e r v a t i o n s  necessary  t o a s s e s s not o n l y  problem,  but a l s o  selecting  t h e most s i g n i f i c a n t  by v a r i o u s Roscoe  testing "The  Flow o f  over  the weight  particles  the  ments,he size,  in h i s  (26),  grain  angle of  size  distribution,  repose,  ports that  wall  resistance  friction,  that,  for  influence  be k n o w n .  Such a s o l u t i o n  Reisner  (27),  are  Behaviour listed  ones  is  to  unit  the  for  for  the  granular  importance of  been here.  model  in h i s  (28),  has d e r i v e d  time,  have  are mentioned  analysis  Fowler  materials and, also  the  segregation  these  paper,  prediction materials  the use o f  bulk  the shape f a c t o r  results.  den-  of  the  orifice,  to  bunker-  and t h e e q u a t i o n s is not yet of  t h e number o f  included variables particle surface  flowability,  of material  all  of  particles,  motion of  in  and o t h e r s .  segregation,  the  the the He  re-  variables need  to  possible.  Granular  the f a c t o r s  grain  characteristics,  the h e i g h t  and  experi-  like  density,  f e e d i n g and d i s c h a r g i n g  the problem of  relating  r e d u c e d model b i n s  To r e d u c e  shape,  to a g g l o m e r a t i o n ,  of  phenomenon  geometrically  particle  t h e method o f  segregation  relevant  testing,  dimensional  degree.  per  b u n k e r and i t s  a solution  In "The  important  d i m e n s i o n l e s s g r o u p s and  s h a p e and d i a m e t e r o f bin,  the use o f  the h e l p of  t h e s c a l e up o f  introduced  are  it  analysis.  studied  bulk materials with  has d i s c u s s e d  the  He has e m p h a s i z e d t h e  considered  that  t o model  Through O r i f i c e s " ,  of  t o be a c h i e v e d ,  them t o a w o r k i n g minimum by  analysis  but o n l y  discharged  true density  Matthee ing of  dimensional  Solids  this  quantities  reduce  mechanics to a c e r t a i n  through o r i f i c e s . sity  to  For  parameters.  has shown  Granular  of  of  authors,  (25),  in s o i l  equations  the p h y s i c a l  to use judgement  Applications described  on a m o d e l .  Materials  influencing  in Flow-out of the e f f l u x  Hoppers"  as u s e d  in  by  the  14. formulae of  various  diameter of  the o u t l e t ,  surface of hydraulic ial,  ful  radius,  friction,  It  it  used w i t h o u t materials.  size,  true  instance, diameter of  reduced area o f e f f l u x ,  flow  gravity,  bulk density  i n c l i n a t i o n of factor  for  all  bin,  of  the  height cohesive  of  the hopper  forces,  the stored bottom,  mater-  specific  there types  of  has c o n s i d e r e d more t h a n a h a n d -  and a c o m p r e h e n s i v e a p p r o a c h  restriction  the  and s p e c i f i c p r e s s u r e on t h e b o t t o m  no s i n g l e a u t h o r  can be c o n c l u d e d t h a t any  for  in the b i n , area o f e f f l u x ,  angle of  is noted that  of v a r i a b l e s  therefore,  grain  acceleration of  shape f a c t o r ,  the b i n .  They a r e ,  the s t o r e d m a t e r i a l  internal  weight,  authors.  is  lacking  in the  i s no f o r m u l a s o f a r , of  b i n s and a l l  literatures, which  kinds of  c a n be  bulk  '5CHAPTER 3 THEORETICAL 3.1  CONSIDERATIONS  Genera 1: A d i s c u s s i o n on t h e d e s i g n o f  model  tests,  must  inevitably  ing,  the a p p l i c a t i o n s of  ials  and t h e i r  3• 2  arching  Theory of  include  flow p r i n c i p l e s  non so t h a t  relationship of  the o b s e r v a t i o n s  the p r o t o t y p e ,  considered  analysis,  this  i n Append i x  p  (  —  (5) o f  '  —  \ ]  l3  l3  = m  p.  *  i.e.,  '  j  / Aim ,  Am  w  I  V  1m  lm ,  is  rewritten  1  2  ,  Dhm , lm  Vcm  ,  Pm  S i n c e each e q u a t i o n in  form.  '  1  for  ,  Wm. Im  to get  in the  The p e r t i n e n t  /°sm V m ddm  ,  an  phenomepredict variables are  refers  the d i m e n s i o n a l  Vc  /°s  l3  ,  dd_ ,  0  form a s :  ,  e  1  the model:  1m  ,  Hm  ,  1m  0  e  0 m  lm  in  ______ »  dm  2  •• o  /•'sm  identical  test-  mater-  the s i m p l i f y i n g a s s u m p t i o n s ,  » 1 ' H  J  />s v  2  ~n—  are  taking part  the s t o p e .  along with  Appendix  —  ]2  Am  model  the granular  the theory of m o d e l s ,  the v a r i a b l e s  A s i m i l a r e q u a t i o n may be w r i t t e n  Vrn  the  I .  Equation  _L  theory of  made on t h e m i n e model may be u s e d t o  the performance of  1i s t e d  to  from  Models:  the  in  the  stopes,  etc.  An a t t e m p t has been made t o a p p l y i n d i c a t i o n of  caving  the a s p e c t s o f  the g r a v i t y  phenomenon,  sub-level  t o t h e same t y p e o f  system,  the  functions  16. Now t h e " L e n g t h length of  S c a l e " i s d e f i n e d as t h e  the p r o t o t y p e  d e s i g n a t e d as n ,  1 in  nl  for  used  in t h i s  analysis,  i n t h e model and  n = 30.  t h e model may be d e t e r m i n e d a s  ~T P  or  In o t h e r w o r d s ,  volume  =  distance  distance  Similarly,  Vm  =  — n-  l  m  3 is  1  =  A l  Dhm Im  _  wm. Im  _  /°bm  -TT—  /->sm  Vcm —=• l m m  3  Aim  in the mine. are  =  ;  or  Am  =  A n  _Dh_  w.  ;  1.  d  T  =  =  =  =  derived:  Ai  2  />s.v  m  Hm 7— lm -  or  or  Dhm  =  1  v2  dm  used  3  3  (lb)  3  (lc)  3  (id)  n  ,2  Tm  bucket  l  Am  /°sm  ;  (la)  3  design conditions  Ai  the  follows:  i n t h e b u c k e t drawn f r o m t h e model  the a c t u a l  the o t h e r  =  Aim  is  From t h e a b o v e ,  (30) times volume o f  or  m  t h e model  design conditions ~T~ Pm  the c o r r e s p o n d i n g  some p e r t i n e n t  or  =  the case o f  of  ratio of  H T  1  Ph x ps Vc —=-  P  ;  or  w  _Dh n n . w . /°s  _  m  2  3  . v^m  (le)  2  ;  or  , dm  =  ; '  or  ,. Hm  ;  or  / bm  ;  or  -  p,  Vc  m  -  d  H — n  =  /°b./°sm —'/>s  =  Vc  .,  3 r\J  /, ,-\ (if)  3  _ /, v  3 ( g) 3  , .... '  3 ( h)  _ /. . v  3  (li)  17. ddm ^  dd —  =  ;  or  ,, ddm  =  0  m  =  0  3 (lk)  e  m  =  e  3 (li)  Design E q u a t i o n 3 ( l b ) - S i n c e  dd  A refers  imposes the c o n d i t i o n o f g e o m e t r i c a l and p r o t o t y p e .  3 (lj)  —  to e v e r y d i m e n s i o n , t h i s  s i m i l a r i t y i n a l l r e s p e c t s between model  Both as to form o f the m o d e l , c r o s s  and l o a d i n g p a t t e r n .  sections  at a l l  Hence, the model was designed a c c o r d i n g to  Design Equations 3 ( l c ) , 3 ( i d ) , 3 ( I f ) , i n d i c a t e t h a t the d e s i g n c o n d i t i o n s  equation  3 Og),  points,  this.  3 ( l i ) , and 3 ( l j )  r e g a r d i n g the area o f o p e n i n g , h y d r a u l i c  diameter o f the o p e n i n g , s i z e o f the p a r t i c l e , head o f p a c k i n g above o p e n i n g , volume o f c o n t a i n e r  and the d i g g i n g depth o f the scoop g i v e complete  in the s e l e c t i o n o f the  length s c a l e between  the model and the  prototype.  Design E q u a t i o n 3 (11) - i s s a t i s f i e d because the same s l o p e near the opening have been used as t h a t  in the model.  1/4") g e n e r a l l y  resembled  The crushed  rock f o r the model  o r e from the ( s i z e s down to  in shape, the broken rock underground.  o f m o i s t u r e has been c o n s i d e r e d Design E q u a t i o n 3 ( l e )  i n the  angles  i n the mine.  Design E q u a t i o n 3 ( l k ) - i s s a t i s f i e d because a c t u a l mine i s used  freedom  No e f f e c t  analysis.  - Here  /° s  Psm  2 Therefore,  w  m  =  n.w.  ^ ™  j  V  - 3 (2)  From Fowler ( 2 8 ) , approximate v e l o c i t y o f d i s c h a r g e v from the o r i f i c e  is  g i v e n by: v  =  •  2g D  n  / nh \  x / ^  j  3  0.185  cms/sec  - 3 (3)  18. Therefore,  w m  =  m  from equations  3 (2) and 3 (3)  0.236 x J 2 g  n.w.  1.236  Dh^  m  J 2g  x  0.185  Dh  m ds„  0.185  x/ h  Dh"  - 3 (4)  D  ds  Since  the v a l u e of  fore,  by s o l v i n g  'g'  is  t h e same f o r  Equation  3 W  n .w.  wm  t h e model and t h e  prototype  there,  , we o b t a i n :  n  or: w.  w,m Therefore, Equation overall  Equation  3 (3) a l l o w s accuracy of  3 (le)  tion  known.  in the  3 (lh)  tests,  sity  (/^b), of  a r e not  To a p p l y  results  model  it  is  flow  rates  practical  limits  since  through o r i f i c e s w i t h  an  + 10 p e r c e n t . -  be a p p l i e d t o t h e draw v o l u m e s not yet  satisfied within  the p r e d i c t i o n o f  Design Equation  is  is  of  ore  -  indicates /^s  corrections  to f i n d  the broken column of this  or  f^ >  stage u n t i l  a r e needed  the e x a c t  nature  to determine the e x t e n t of extraction  the s w e l l ore  corrections but  s  r e c o v e r y and t o t a l  imperative  p o s s i b l e at  m  that  factor,  in the s t o p e .  a working stope  of/^b distor-  obtained from thereby  to  the  the b u l k  den-  These measurements  i s - a v a i l a b l e for  such  tests. In c o n c l u s i o n consolidation effect tween t h e m i n e o r e  it of  c a n be s a i d t h a t , due t o d i f f i c u l t i e s blasting  i n t h e s t o p e and t h e d e n s i t y  and t h e model o r e  due t o n e g l i g i b l e  in s i m u l a t i n g difference  expansion of  the  be-  blasted ore It  in  is c l e a r ,  the m i n e ,  however,  which a r e not the mine.  So i t  The ciple  is,  gravity  Typical  C a v i n g method a r e  ring width  P of The  between  detailed effective  the  sub-level  slice. Sub-Level  respectively.  3,  by a g r a v i t y  flow  and t h e w a s t e may c o n t a i n  meters of  sub-level  distance h,  of  of large  Rj of  ,  the optimum;  determining  the w i d t h  of  the e x t r a c t i o n  can o n l y  However,  2 (3) g i v e  the  sub-  s l i c e Z^, drifts  and  approximate  applicable  t h e draw f i g u r e s  sub-level  the the  basic  figures  in p l a n n i n g  in the d e s i g n of  are symmetrical  caving,  be f o u n d on t h e b a s i s  Janelid's  c a v i n g w h i c h c a n be a p p l i e d  The a b o v e a r e d i r e c t l y  contamination  to determine  the parameters o f  factors,  conditions.  2 (2) and E q u a t i o n  c a v i n g where  the  prin-  drifts.  p r e c i s e optimum v a l u e s  (Equation  level  in  in  and L o n g i t u d i n a l  is mainly a matter of  B and h e i g h t  natural  of  is necessary  the width  under  Caving:  corresponds  c l e a n o r e and m i n i m i z e  c\ ,  the  tests  This  it  of  retreat  all  from  in Sub-Level  by  the w a l l  results  testing.  flow  characterized  the b l a s t  including  caving  Transverse  S,  the p i l l a r s  type of  results  so.  losses,  the s l i c e .  in the model.  qualitative  the g r a v i t y  the b l a s t e d ore  the p r o d u c t i o n  as o r e  is  give  the Parameters  2 and F i g u r e  c a v i n g method  16 i n c h e s o r  interval gradient  in F i g u r e  this  in s u b - l e v e l  because  represented  than c o r r e s p o n d i n g  out  in t h e Case o f  because both  by w a s t e as w e l l  level  better  to c a r r y  1 (l)  a r e not  crushed ore  speaking, cut-off  shown  To o p t i m i s e  parameters of  or  material  Figure  sub-level  lumps o f o v e r  higher  flow of  sections  lumpy m a t e r i a l  with  F l o w and D e t e r m i n a t i o n o f  figuratively  The  conditions  tests  |s j u s t i f i e d  to the case of  caving  that  necessarily  Gravity  3•3  right  of  formulae  for  the  para-  the m i n i n g system. Transverse  s o l i d geometrical  subshapes  ~1 0  tr  19  90- V  FIG. 2 A  DIAGRAMMATIC V E R T I C A L SECTION THROUGH LONGITUDINAL AXIS OF EXTRACTION DRIFT  FIG. 2  TRANSVERSE  SUB L E V E L  FIG. 2 B  CAVING  DIAGRAMMATIC VIEW OF T H E SLICE SECTION l - l O F FIG. 2 A  WALL  IN T H E P L A N E  OF T H E  O  FIG.  3A  DIAGRAMMATIC LONGITUDINAL  FIG.  3  VERTICAL AXIS  LONGITUDINAL  SECTION  OF E X T R A C T I O N  SUB  LEVEL  THROUGH DRIFT.  CAVING  FIG.  3B  DIAGRAMMATIC PLANE  OF T H E  VIEW  OF T H E S L I C E  SECTION  J-J  WALL  OF FIG.  3A  IN T H E  22. but  in the case of  m e t r i c because of the s t o p e .  Longitudinal  Sub-Level  the almost p a r a l l e l ,  Therefore,  draw f i g u r e s  Caving  draw f i g u r e s  inclined footwall  a r e not  sym-  and h a n g i n g w a l l  a r e t o be d e t e r m i n e d f o r  each  of  different  conf i gurat i o n . Considerations drift the  width,  height,  ring gradient,  Sub-Level  etc.  etc.  blast  are d i f f e r e n t  3.31  flow throat,  the d e s i g n c r i t e r i a distance,  Interval:  factors  S = f  interval  such  h'  (K,  c,  as t h e p a r t i c l e  h = Height  of  c = s i z e of  The o t h e r  legends  v, the  R , d  are  Longitudinal  the s u b - l e v e l  interval,  location of  drift,  considerations:  the  x,  m,  B,  P, %  3 (5)  )  c a n be e x p r e s s e d  in  simpli-  size  discharge t h e same a s  The a p p r o x i m a t e s u b - l e v e l caving  and  by a s y m b o l i c f u n c t i o n o f  lumpy m a t e r i a l w h i c h  the g r a v i t y  of  as  from the f o l l o w i n g  c a n be e x p r e s s e d  the e x t r a c t i o n  v = velocity  the scoop  as:  K = Properties of for  fragmentation,  each method.  Sub-Level  effective  for  l o a d i n g p a t t e r n and  M o d e l t e s t i n g was g u i d e d  sub-level  depth of  c a n be common t o T r a n s v e r s e a s w e l l  retreat for  p a r a m e t e r s s u c h as  the digging  Generally,  The  Where  to the design of  Caving method, but  p i l l a r width,  fied  drift  given  i s c a l c u l a t e d from the  flow. area. from the  opening.  in Figure interval  formula:  2 and F i g u r e  in the case of  3Transverse  sub-level  2  Where R j  i s the  multiple  of  The  blast  ring  r e s t r a i n t on  t e s t w o r k was  level  intervals  C  the  the  imposed,  can  T h e r e can  Sub-level  be  interval  and  (47)  trajectories  of  the  cipal  in the  2  -ty*,  depth x  the  taking The In was  f' =  digging the  model  used.  h  the  burden or  a  be  30'  60'  or  for  the  30'  compatible with  transverse sub-level  sub-  caving of  the  same d e v e l o p m e n t a l w o r k f r o m t h e  that with  and  1  either  no  such  restraints  between the  figures  as  ramp  above,  30'  of  to  and  60 . 1  h i g h e r , h o w e v e r , have t o meet o t h e r  add-  requirements.  R a n k i n e ' s t h e o r y on  into  stresses  the  slope.  natural  points  are  angle of  1 and  2  legends of  and  the  d i s t r i b u t i o n of  calculated  The  optimum  t r a j e c t o r i e s of  inclined against repose.  i n the  the  above  The  the  the  vertical  theoretical  prinby  best  figure.  F i g u r e 2,  theoretical  ^90°  ^  best depth  is  formula:  .cot^  50°  the  ( F i g u r e 3a)  slope  In c o n f o r m i t y w i t h from the  60  applied  i s the  i s g i v e n by  x ^  ring  Scooptram:  scooptram  where y  calculated  a  3690' t o a b o u t 2900', so t h a t a c c e s s  maximum p r i n c i p a l  p e n e t r a t i o n of stresses  be  of  i t to  might e x i s t  economical  has  the  of  for the  of  a possibility  Digging depth of Janelid  for  made w i t h  interval  technical  3-32  ( w h i c h can  interval  in order  elevation  be  optimum s u b - l e v e l  itional  sub-level  already accepted  orebodies  system.  30°  the  o r e b o d y between the  all  distance  burdens).  model  1  retreat  3-  for  -  h.  tan  Granduc o r e .  depth a p p l i e d  x  in p r a c t i c e  t e s t s , a d i g g i n g depth of  =  - f 5-16  should  3  ft. reach the  approx. 2  in.  theoretical (2  i n . x 30  figure.  = 5  Ft.)  (7)  2h. 3 .33  Drift  Width:  W h i l e p l a n n i n g t h e minimum w i d t h o f r o c k has b e e n c o n s i d e r e d and u s e d  the d r i f t ,  in the f o l l o w i n g  fragmentation of  the  formula from J a n e l i d ( 4 7 ) .  3 (8) Where D i s factor of  the diameter of composition of  the  largest  lumps o f  the fragmented  rock  t h e b l a s t e d o r e and k i s  ( u s e d Nomograph f r o m  the  Janelid  (k7) P. 144.) For  the c a l c u l a t i o n of  rock c o n s t i t u t e d of up t o k0%. is  If  almost n i l ,  lumps up t o  percentage of  steep  longitudinal proper this  Location of  drift  This ensures difficulties,  and damp c o n s t i t u e n t s t o be e q u a l  drifts  tests  gravity  is  fragmented  to  size  s u c h as p o w d e r ,  12.0 f t .  and i f  etc.  fines  are  ft. h a v e been u s e d f o r for  equal  The minimum s i z e o f  stopes  12 f t .  of  l o a d i n g from the s i d e s w i t h  the d r i f t x  the p l a n n i n g  12 f t .  f l o w and a l s o p e r m i t s  used  in the narrow  This conforms the use o f  and  to the  production  an  redrill  dimension.  Drift:  Theoretically, when w i d t h o f  1 6 " and assumed t h a t  k0%, medium s i z e up t o 20%, s m a l l  15-5  caving stopes,  wide scooptram.  3.34  ^  wide e x t r a c t i o n  8 ft.  jumbos w i t h i n  16"  then B c a l c u l a t e s out  Transverse sub-level  quirement of  used D -  fines  c o n s i d e r e d up t o 5%, t h e n B 16 f t .  k,  ideal  layout  = width of nearly  the best  for  the t r a n s v e r s e  sub-level  stopes  is  pillar.  parallel  arrangement  gravity is  flow.  to p r o v i d e  However, for  side  due t o  slopes.  practical  25. In before  the case of  elsewhere  d u c e d by  that  locating  all  equipment, cation,  marginal  fully  wide  bodies  The e x t r a c t i o n and by lel  of  the  form  ating  this  reach of  the e x t r a c t i o n is e a s i l y  is  the drift  avoided  ring  smaller  is  3.36  Ring  side.  the  t h e F.W.  clear  in the  This  last  -  indicated  c a n be  that  m u s t be made f o r  re-  in order  this  mine,  the p r o d u c t i o n F.W.  point  at is  to con-  drilling  a particular  lo-  particularly  in the case of  very  Loading:  by  the o p e r a t i n g  reach of  the  scooptram  f l o w a p p r o a c h e s more c l o s e l y  in the case of  more f u l l y  has been  drilling.  is given  Tr.  and t h e  Sub-level  caving)  loading system covers  undesirable  arching of  the  if  a paralthe  oper-  the w i d t h  of  lumpy m a t e r i a l  way. longitudinal  t o draw more b r o k e n o r e  hanging w a l l  is  it  are needed, e s p e c i a l l y  is wider  When m i n i n g t h r o u g h appropriate  it  content  The g r a v i t y  ideal  this  a study  I n t e n s i t y of  width  loader  but  problems.  to s u i t  loading system.  (and  losses along  F.W.,  the ore  drifts  Loading Pattern or  3-35  in the  rock s t a b i l i t y  dipping ore  the o r e  although  s u c h as t h e p e r f o r m a n c e o f  values  i m p o r t a n t when e x t r a flat  stopes,  most f a v o u r a b l y ,  factors  and t h e  generally  the d r i f t  l o c a t e the d r i f t s sidering  longitudinal  Loading at  i n c l i n a t i o n of  drifts  from the  the f o o t w a l l the  in narrow  footwall side  side  s h o u l d be  deposits  it  than from  is the  increased,  the  deposit.  Gradient:  Research the  fan a n g l e ,  the  r a t i o of  i n Sweden has  within  average  indicated  the angle ore  sizes  duced a s i m p l e t a b l e which  is  that  l i m i t s of to waste  60 - 120°,  sizes.  reproduced,  the optimum r i n g  gradient  or  is m a i n l y dependent  Janelid  in a s l i g h t l y  and K v a p i l  (47)  modified form,  on pro-  below:  26. Ratio of  away  1  Positive,  a  Ko/Kw  =  1  Vertical,  a = 90°  KQ/KW  <  1  Negative,  a >  the average  particle  t h e w a s t e and  The  is  theory  is  of  ore  into  A m a t e r i a l of force,  fill  particle  size,  gradient  is  the  retreat  that  the  the o r e ,  between  (see  Fig.  ring gradient  the  intermixing  is  <90°  90°  the average  the h o r i z o n t a l  particle  and t h e  fan,  2 & 3)• ol, i s  t o have  the e f f e c t  of  pre-  of waste o r ,  inversely,  the  in-  waste. fine  lower  i.e.,  size of  the angle  as much as p o s s i b l e ,  termixing of  al  a  >  from the d i r e c t i o n  venting  Fan A n g l e ,  Ko/Kw  Where KQ i s s i z e of  Rock S i z e s :  particle  lying  f i n e ore  size  cavities  and gaps  lying over  so c h o s e n s u c h t h a t  c a n , as a r e s u l t in  of  the  gravitation-  the m a t e r i a l of  lumpy w a s t e o r  the optimum c o n d i t i o n s  vice  versa.  are obtained  coarse The in  ring this  respect. The tions  —  ring  gradient  is,  however,  a l s o dependent  on m i n i n g  s u c h as m a i n t a i n i n g a good brow and a good d r i l l e d  efficiency.  Probably  because of  these c o n s i d e r a t i o n s ,  mines have a d o p t e d a backward s l o p i n g most h a v e a d o p t e d a n g l e s  varying  ring  gradient  or  very the  considera-  footage few,  if  any,  fan angle  f r o m 7 0 ° t o 9 0 ° , d e p e n d i n g on t h e s e  and condi-  tions . For  the purposes  w e r e a s s u m e d t o be e q u a l  of  model  work,  and h e n c e o n l y  w o u l d need m o d i f i c a t i o n s , h o w e v e r , Ko  test  if  fragmentation of  vertical  in a c t u a l  fans  ore  and  waste  h a v e been t e s t e d .  practice  it  is  found  This  that  27. Blast  3-37  Retreat  Distance:  From a t h e o r e t i c a l  point  be g o v e r n e d  by many f a c t o r s .  function  the f o l l o w i n g  of R  Where  =  d  the  first  remaining  to  and 3 a . slice  (K, four  factors  The respond  f  h'  c,  factors  blast  the g r a v i t y  where  v, are  S,  the b l a s t  m,  t h e s e may be  B,  c\  will  R, A  by a  symbolic  interdependent.  3 (9)  )  in Equation  should,  the b l a s t e d ore  sub-level  distance  3 (5) a n d  the  2 and 3-  distance  retreat  retreat  c a n be e x p r e s s e d  t h e same as u s e d  retreat  flow of  it  some o f  x,  in Figures  The o p t i m u m b l a s t  in a transverse  view,  In p r i n c i p l e ,  factors,  as shown  proper  of  distance  in the optimum c a s e ,  i n t h e way  (See  Fig.  shown  cor-  in F i g u r e s  2 £ 3) f o r  a  s t o p e c a n be c a l c u l a t e d f r o m t h e  2a  vertical  approximate  formula. R  Substitute Janelid  Blast  value of  (47, F i g .  Therefore:  R  transverse  distances  sub-level  drawn, blast  draw.  for  of  Equation  - (.975)  retreat  for  longitudinal  all  parameters  height  and the mine d e v e l o p m e n t a l  i n t h e model  for  the  of  are  ft.  tested  the c a l c u l a t i o n of  sectional  are  p i l l a r width,  from  1  3 (10).  sub-level  distances other  ft.  'S  method.  available  Therefore,  30  interval  > 6.60  2  5, 6 and 7 f t .  caving is  a sub-level  and b a s e d on e s t i m a t e d b e s t  After val,  3 (10)  )  = 0.975,  30 J~\  in the case of  metrical  2  2 9 , PP 142) i n  No f o r m u l a tance  e  >  d  retreat  (1 - e  S J  >  d  blast  retreat  c a v i n g method b e c a u s e o f  diagrams  recoveries  for with  disunsym-  each c o n f i g u r a t i o n least  dilution;  are  optimum  developed.  and w i d t h work  is  h a v e been c h o s e n , of  extraction  started  such as s u b - l e v e l  drift  and r i n g  and k e p t a h e a d o f  burden,  production  interetc. date  28. for  a year or  two.  Blast  retreat  t a n t v a r i a b l e w h i c h may g i v e A change content. of waste bably  This  in b l a s t  cover  almost eight  retreat  concern  in a y e a r .  accentuate this  problem, unless  devised.  varying  Also,  consolidation iable  air  leaking  (due  method.  study  retreat  in  charges  rock)  is useful  moisture  small  it w i l l  the cave  to the nature of  mat o f w a s t e  impor-  is covered with  through  smaller explosive  type of  d e t e r m i n i n g an o p t i m u m b l a s t  in t h i s  Granduc Mines because of  a t e r r a i n which  fragmentation  This  flexibility  t h e most  some a l t e r n a t i v e means o f w a t e r  the o v e r - l y i n g  of moisture content.  by f a r  When t h e c a v e s t a r t s ,  Any h o t  ( c a u s e d by b i g g e r o r  thickness of  for  catchment area of  months  then,  d i s t a n c e c a n occur by v a r i a t i o n  t h e t o p most l e v e l .  a large  is,  any c h a n c e o f  is a matter of  rock above  distance  cover pro-  snow, might  diversion  are  ground,  etc.)  and  and/or  by a  var-  hold d i f f e r e n t  from the p o i n t  of  amounts view  of  distance.  T h e r e a r e two a l t e r n a t i v e s w h i c h c a n be c o n s i d e r e d  from a p r a c t i c a l  standpoint. 1.  In  the case of  ness  before actual  throughout, which  is  To s t u d y  production,  the s u b - l e v e l  in p a r t i c u l a r l y  the v a r i a t i o n  beforehand with the mine  s u b - l e v e l s which w i l l generally  may h a v e  an e x a c t m u l t i p l e o f  profitable 2.  ring d r i l l e d  the  and a l s o e x p e c t e d w e t n e s s  and d e s i g n e d a c c o r d i n g  ferent  portions  to  a uniform ring  burden  retreat  in order  distance  t o be most  the  the e l l i p s o i d o r cave rock  limits  in the area -  varied  readi-  situation.  particular  ( r o c k may b r e a k b e t w e e n  of  burden  i n t h e depth o f  respectHo  in  to use a b l a s t ring  changed  with  be k e p t  type t o be e n c o u n t e r e d of  so t h a t  very f i n e  to  r i n g burdens  the s p e c i f i c c o n d i t i o n s  t h e same s u b - l e v e l .  figure  for  in  coarse) may be dif-  29. If  the  i s a need o f  first  developing  to conform w i t h retreat  alternative  i s more p r a c t i c a l  some f l o w c o r r e c t i v e  the nearest  and a c c e p t a b l e ,  then  there  measures to cause the  rock  flow  s i n g l e o r m u l t i p l e r i n g burden  -  d e f i n e d as  blast  distance. Principles  of  t o know t h e c h a n g e  arching  in the  in the depth o f  ideal  soils  have been u t i l i z e d  the e l l i p s o i d of motion behind  in  order  the  solid  face. From T e r z a g h i encountered  in s o i l s  the support  of  soil  adjoining  adjacent  both  a mass o f  the y i e l d i n g stationary arch over  part of  parts  section a.b.  of  of of  The  and  to  the s u r f a c e ,  the zone o f  one p a r t  in p l a c e ,  position  contact  it  reduces  1  the  soil  between  resistance  of  between  the  the  tends  to  the pressure  on  t h e p r e s s u r e on t h e  l o c a l y i e l d of  According  and t h e s o i l  the h o r i z o n t a l  by g r a d u a l l y  to  the  sufficiently  adjoining is  said  radial  shear s t r e s s  i n a downward  s l i d i n g which  rise  the g r a n u l a r  photographs,  support  lowering a  to  from the  Terzaghi  downward. (hO).  of  a  strip-shaped theory,  direction,  material.  t h e g r a i n s move v e r t i c a l l y  b e e n d e m o n s t r a t e d by t i m e e x p o s u r e  If  r e l a t i v e movement w i t h i n  increases  the s u r f a c e of all  its original  phenomenon  support.  two s u r f a c e s o f  the s t r i p  of  position,  c a n be p r o d u c e d  has y i e l d e d  remainder stays  'arching effect  the  F i g u r e h the  laboratory.  S i n c e the s h e a r i n g  its original  the s u p p o r t .  along  the  moves o u t  masses.  part of  material  s o o n as t h e s t r i p f a i l u r e occurs  to  while  soil.  the support  the y e i l d i n g  granular  yields  part  t h e most u n i v e r s a l  f i e l d and i n t h e  i n commonly c a l l e d  Referring  boundries  mass i n  i s one o f  resistance within  and t h e s t a t i o n e r y  keep the y i e l d i n g  vicinity  soil  masses o f  i s o p p o s e d by a s h e a r i n g  bed o f  in the  the y i e l d i n g  stationary  yielding  arching  (kO),  as  a shear  outer In  the This  has  30.  A  FIGURE 4.  FAILURE IN COHESIONLESS GRANULAR MATERIAL PRECEDED BY ARCHING. (A) FAILURE CAUSED BY DOWNWARD MOVEMENT OF A LONG NARROW SECTION OF THE BASE OF A LAYER OF GRANULAR MATERIAL. (B) ENLARGED DETAIL OF DIAGRAM (A).  31. S u c h a movement tersect  the h o r i z o n t a l  faces of lines  and b ' . d .  have not  yet  been s o l v e d .  In  the case o f  draw p o i n t  (45° + 0 12) the eventual determining  o  r  t  n  [k5°  larity,  particle  internal  + 0 /2) »  to  T* Where  <r i s  shear  stress  equal  to zero f o r  on t h e  s  blast  stopes,  of  of  study of  =  0 - tan  +  stress  failure  sliding  Hence, Figure  the  k by  plane at  the  have s u g g e s t e d  that  from almost  90° f o r  high values  a high value of  b.d.  o f Z/2hexists  overlying  in the  angle  the opening  is very  the  low  Z/2b  rock  the v a r i a t i o n  and  important  in  for  of  distance.  void  in the e x p r e s s i o n ratio,  Failure  moisture  angle  content,  angu-  etc. Law'.  3 (1 D  failure failure,  plane at C  failure  stands  for  m a t e r i a l s and 0 i s a n g l e o f  the p r e c e d i n g  sur-  and  0  on the  in-  s l i d i n g a.c.  t h e b r o k e n mass n e a r  pressures,  Coulomb  in  t h i c k mat o f w a s t e  '0' u s e d  'Mohr -  0 in  indicated  + 0 12) f o r  retreat  function  C  angles.  the curved s l i d i n g s u r f a c e  Cohesionless  of  in  friction, a  that  {h5°  a fairly  and c o n f i n i n g  the normal  Values  equation  and  T* i s  Cohesion internal  c a n be d e t e r m i n e d  the  and  is  friction  by means  of  tests.  In o r d e r  as  '  size  According  vertical  of  surfaces of  right  decreases  caving  siiding  at  the  the s u r f a c e s  Therefore,  t h e most s u i t a b l e  sliding  the y i e l d i n g  ore.  development  Angle of  laboratory  sub-level  if  the experiments  approaching  angle of  e  for  However,  considering  the b l a s t e d column of  to  these surfaces  Z/2b t o v a l u e s  only  material  The e q u a t i o n s  slope angle of  values of  near the  surface of  s l i d i n g have a shape s i m i l a r  a.c.  average  is c o n c e i v a b l e  to c a l c u l a t e  strip  -  Terzaghi  i n d i c a t e d by  the  the s t a t e of  stress  located  has a s s u m e d t h e s u r f a c e s lines  a'.e.  and b ' . f .  of  immediately  above  s l i d i n g are  to  ( F i g u r e h.).  T h i s way  be  the  32. problem of identical ing  computing with  bottom of  the v e r t i c a l surface  for  the v e r t i c a l  the problem of  pressure  computing  the p r i s m a t i c b i n s . stress  The  the v e r t i c a l following  on a h o r i z o n t a l  a Cohesionless  on t h e y i e l d i n g  section  strip  pressure  formula  is  becomes  on t h e  used to  a t any d e p t h  Z  yielddetermine  below  the  material.  3 (12) Where  K  =  R a t i o between as  =  Half width of  0  =  Angle of  Y  =  Unit weight a unit  b = 8, 0 = 4 2 ° , Z  (See  Figure  -  Taken  strip,  5)  resistance.  of  the g r a n u l a r  material.  width of  the y i e l d i n g  strip  T = 100 I b s . / c u .  887-9  =  887-9  Corresponding computed  and by s u b s t i t u t i n g  K = 1,  ft.  lbs./sq.ft.  or  6.15  P.S.I.  lbs./sq.  normal  stress  ft.  or  (crh)  6.15  P.S.I.  on t h e v e r t i c a l  s u r f a c e of  s l i d i n g c a n be  from:  OZ. -  the p a r t i c u l a r for  is a p p l i c a b l e to  case of  a sub-level  Convergent hoppers  f l o w a r e more in  3 (13)  K. o - v  The a b o v e a n a l y s i s  outlet  shearing  the y i e l d i n g  pressure  = 160'  Z  derived  the s t r i p  and t h e v e r t i c a l  = 6 0 ' =  For  immediately above  b  Considering  For  unity  the h o r i z o n t a l  relevant  stopes.  with  the  flow  caving  stope with  surcharge  in c a l c u l a t i n g  i n an o p e n m a s s , b u t side  (See W a l k e r  the nature of  slopes  considering -  formulas  (10) ) f o r  stresses  close  to  massthe  33. The a v e r a g e v e r t i c a l V  r  =  Substitute  the  h 1  pressure  V is given  by t h e f o l l o w i n g  formula:  c  0  following  T  =  100  C  =  3.13  "(fe)  - ' )  c  in Equation 3  +  °  v  (fe)  c  3 ( ,  *>  (14)  lbs./cu.ft.  ( t a k e n as  the n e a r e s t  P . 9 9 4 ; f o r c_, =  approximation  15°,  0  =  from Walker  S =  40° a n d  (10)  Table  2;  50°)  and f r o m F i g u r e 5 h  c  =  41  feet  h  Q  =  60  feet  V  Q  =  100 x  =  loo  v  100 l b s . / s q .  (\ (\  x 4i  ft.  -- Ai Ai  as t h e  surcharge  \\ 2.13) 2.13)  + +  10,000 10,000  Ai Al "\"\  3-13  2.13 28.5 A range o f (14)  which  P.S.I  confining  represent  the pressure  coupled with  a range o f  the m a t e r i a l  used were  laboratory sented  3.4  at  U.B.C.  in Chapters  Design of In o r d e r  A.  of  at  derived  from Equations  the o u t l e t s  moisture content  of  tried with  t e s t e d by means o f T r i a x i a l Details of  tests  different varying  3 (12)  and 3  stope  layouts  sieve  sizes  t e s t i n g machine in  c o n d u c t e d and t h e i r  results  of  the  are  pre-  4 and 5  M a s s - F l o w B i n s v/s  Stope  to assess the s u b - l e v e l  f l o w b i n and f u n n e l - f l o w variety  pressures  situations  bin condition,  can d e v e l o p .  Transverse sub-level  stopes:  For  Design:  caving  s t o p e s on t h e b a s i s o f  the f o l l o w i n g  analysis  shows  mass-  that  example:-  c a n h a v e m a s s - f l o w c o n d i t i o n on  three  a  34.  PRESENT EXTRACTION DRIFT-H  FIGURE  5.  STANDARD  T R A N S V E R S E SUB L E V E L  CAVING  LAYOUT.  35. s i d e s and p l u g - f l o w side slopes  c o n d i t i o n on o n e s i d e  t o t h e n e x t sub  f l o w c o n d i t i o n on t h r e e  B.  Longitudinal  1.  Narrow  level  (back-end)  a b o v e and b e y o n d  that  Narrow  Sub L e v e l  Stopes:  & steeply* dipping  £ gently  dipping  Wide o r e b o d i e s , (2 E x t r a c t i o n  h.  Wide o r e  has  plug-  side.  PIug-Flow  stopes  dipping  =  3 sides  1 side  =  2 sides  2 sides  =  2 sides  2 sides  =  1 side  3 sides  stopes  on same l e v e l )  gently  drifts  it  the  stopes  steeply  drifts  bodies,  (2 E x t r a c t i o n  height  Mass-Flow  can have 3.  t h e end o f  s i d e s and m a s s - f l o w c o n d i t i o n on one  can have 2.  up t o  dipping  stopes  on same l e v e l )  F.W.  drift or  2 sides H.W.  2 sides drift  NOTE: * Steeply  d i p p i n g w o u l d mean:  From t h e a b o v e more v a r i a b l e s Walker  theories  it  appears  as compared t o of  dip of  gravity  above.  that a stope design w i l l  present  the b i n d e s i g n a n d , t h e r e f o r e ,  f l o w as a p p l i e d f o r mass f l o w  need a c o n s i d e r a b l e  improvement b e f o r e  the g r a v i t y  blasted  flow of  7 5 ° and  rock  in the  their  many  Jenike  and  in hoppers  and  a p p l i c a t i o n c a n be e x t e n d e d  stopes.  bins to  36. CHAPTER  4.  CONSTRUCTION AND OPERATION OF THE TESTING EQUIPMENT.  4. 1  General: The model and a l l  s c a l e of  1:30.  was f o u n d allow  Preliminary  t o be t o o s m a l l  proper  4.2  to permit  it  pattern.  are  s c a l e , but sectional  this  the  scale  diagrams  was made w i t h  to work w i t h ,  to  and  1:20  as t h e c h a n c e s  of  reduced.  Construct ion:  18  in.  vertical  deep.  (see  sides,  moveable  sub d r i f t s , front wall  etc.  1/2"  A provision  the e x t e n s i o n extension required placing  round  for  lowest  It  inside  bars,  was made f o r t h e model  testing  an a d d i t i o n a l t h e model  flat  dipping  plexiglass in p o r t i o n s  c o u l d be done  x 4"  level  positions  plywood,  the  while  the  the  low h o r s e s ,  to prevent  was  re-  plexiglass bulging, permitted  when d e s i r e d . .Upward  and s i d e e x t e n s i o n  stopes.  ease of  The  two  of  the model, which  tests  wide  lumber, with  the model. irons  p l a t e on t o p o f provided  in.  as s i d e w a y s ,  longitudinal  comfortably.  high x 4 f t .  frame c o n s t r u c t i o n  frames f o r  as w e l l  doing m u l t i p l e  2"  1/2  The  by h o r i z o n t a l  two s i d e  upwards  of  strengthened  The model b o x was p l a c e d on two part  with  plexiglass. which  3 ft.  to a l l o w d i f f e r e n t  was c o v e r e d  1/4"  a box,  was made o u t  t h e box  on t h e o u t s i d e  i s needed w h i l e  building  model.  of  6)  The b a c k w a l l  f r o n t was s u p p o r t e d etc.  Figure  was c o v e r e d w i t h  inforced with  of  1:60  One t e s t  The model was made i n t h e s h a p e o f x  have been c o n s t r u c t e d  the drawing of  i t was f o u n d much e a s i e r  and d e v i a t i o n s  for  t e s t s w e r e made o n  s t u d y on the d i g g i n g  s c a l e model and disturbance  accessories  is  T h i s was a c h i e v e d  first  one.  This  feature  l o a d i n g and u n l o a d i n g so t h a t  scooping  by  from  the its  FRONT  FIGURE 6 A .  MINE M O D E L  VIEW  A S S E M B L E D FOR  SIDE  T R A N S V E R S E SUB L E V E L  CAVING.  VIEW  FRONT VIEW  FIGURE 6B l i l MINE M O D E L A S S E M B L E D FOR LONGITUDINAL  SIDE VIEW  SUB L E V E L  CAVING. V_v>  CO  FIGURE" 6B (iii)  ko. Ore a n d W a s t e M a t e r i a l :  k.3  It blasting  t h e maximum s i z e o f  It  is  known, however,  that  A v e r a g e g r a d e o r e was b r o u g h t  laboratory  crusher.  Choke f e e d  p r o d u c e d more a n g u l a r o r e crushed  rock  into  particles.  in the mine.  operation.  k,  of Appendix  was p r e p a r e d . Although  hangingwall,  it  t h e same as t h a t characteristics tests  With normal  i n some o f  the o r e m a t e r i a l  III.  about  testing,  the ore m a t e r i a l p a r t i c l e s  t o be n e a r l y  for  reasons d e t a i l e d  However,  t h e same s i z e as t h a t o f o r e was u s e d  Drifts  The e x t r a c t i o n s c a l e d down t h i r t y  times.  and L o a d i n g B u c k e t ,  drifts The  lbs.  of  w e r e made o u t o f  to  actual is  in-  crushed  ore  beside the model. the  is  caved  to  be  flow  No o r e and w a s t e  r e c o v e r y and w a s t e  intensity  drifts  the g r a v i t y  the o r e .  mite crushed  Extraction  t h e same  in the  s i z e of waste  tests  k.k  loading  the  in each t e s t  5,000  and a l s o ,  i n S e c t i o n 5-4. the  that  in a p r o p o r t i o n  used  demonstrational to  and f o r  since  the f r a g m e n t a t i o n o f  t h e same as t h a t o f  have been p e r f o r m e d t o d e t e r m i n e t h e o r e  estimates  in a small  the shape o f  in the bins  that  12 i n .  recovery  the experimental  Approximately  known y e t  i s a s s u m e d , f o r model  production  range t o  ]/k i n . , had a p p r o x i m a t e l y  The o r e was t h e n p l a c e d  n o t much i s  of  feed,  s i m i l a r t o w h a t was e x p e c t e d  The s c r e e n a n a l y s i s o f  in Table  material  t h e c r u s h e r was a v o i d e d ,  r o c k was s c r e e n e d and t h e n m i x e d  have f r a g m e n t a t i o n d i s t r i b u t i o n  in the  f r o m t h e m i n e and c r u s h e d  the broken o r e observed  Crushed  size  from the  c o a r s e f r a g m e n t a t i o n makes t h e  down t o a minimum s i z e o f  s h a p e as t h a t o f  cluded  the ore  s h o u l d n o t e x c e e d 20 i n . and t h e a v e r a g e  - 16 i n . worse.  was a s s u m e d t h a t  for  tests,  dilution  the purposes  etc.,  white  of  dolo-  in the model.  Etc.: 1/6" g a l v a n i z e d  l o a d i n g b u c k e t was made o f  plates,  1/16" s t e e l  plate  41. and  its  design  is  (30)3  =  with at  then the  1:20  are approximately turned  around  thumb a t scale.  For  Blast  4.5  of for  tables,  this  purpose,  The model  plates,  testing.  volume  separating  It  of  1/16"  a new  the d e s i r e d  blast  etc.,  The  of  was  arranged  and  scoop-  1:30  scale  plate,  (see  tests.  during  Figure  This  mill  7)•  laboratory  p l a c e was a v a i l a b l e  here  to accommodate  area  entirely  benches,  t o do any  fittings  and c a r p e n t r y  some s o r t w e r e  required  almost a f t e r  of  the  cave f i g u r e  the  drift retreat  front hole,  desired  plexiglass is pushed  angle of  side slopes,  or  t h e draw f i g u r e s  as d e s c r i b e d a b o v e .  distance.  This  panel.  into  work, every  repose of  the d r i f t .  slope angle.  For  have  A drift  A wooden  etc. test  the hole  the  rock  opening  is  with  t h e same d i s t a n c e  in  transverse S l o p e s were  longitudinal  been  block,  b l o c k was c u t w i t h  in the case of  p l a c e d on e a c h s i d e o f  wood b o x e s w i t h  drifts  handle  configuration.  s o as a n a t u r a l  be d e v e l o p e d .  t h e muck  and w a s t e c o l u m s  in a f u t u r e  convenient  t h e model a r r a n g e d  the  One t e s t  extraction  sheet  x 20 f t .  was q u i t e  the bottom of  in the f r o n t  40 f t .  t h e model o f of  raised.  the ore  into  char-  the M o d e l :  and t o o l s ,  t h e same s h a p e as  were  Its  down t h e d i g g i n g  t h e same a s t h a t  t e s t s were c a r r i e d out  c a r r i e d out with  test,  by p r e s s i n g  The model  to  b u c k e t was p u s h e d  a new s e t o f box was  used f o r  Determinations  as  points  of  screens  at  pivot  The  Operation  the s t a r t  cut out  the same.  t h e model w e r e made o u t  Alterations for  its  the dimensions approx. model  the scooptram ST-4A.  t h e same t i m e t h e b u c k e t was  t r a m b u c k e t was m a d e .  loading of  s c a l e d down c o p y o f  27000 t i m e s l e s s t h a n t h e s c o o p t r a m b u c k e t and i t s d i g g i n g  acteristics pile,  is exact  sub  an  incline  t h e model  sub  level  caving  s i m u l a t e d by level  could  ply-  testing,  the  FIGURE 7B  WOODEN BLASTING BLOCK , EXTRACTION  DRIFT, AND  BUCKET  43. t h e H.W.  and F.W.  the base o f with  panels were f i x e d a t  t h e model s o as t o a d j u s t  respect  to  the f o o t w a l 1 .  a f a l s e f l o o r was b u i l t cut  into  it.  The model was  for  Whenever  on t h e t o p o f  See F i g u r e  t h e d e s i r e d a n g l e and a d j u s t e d  loaded w i t h  F.W.  the  15 i n A p p e n d i x  the proper  location of  panel  pattern  (5  in.  were  ft.  5ft.,  x  required  for  for  flatly  particular layer vide  test.  after  A total  This  l e f t of  about  expected cave f i g u r e  contour  (50 f t . ,  understudy.  t h e wooden b l o c k , w h e r e a f t e r ,  of  at  the bottom  and t h i s repeated  f a c t was n o t e d on in t h i s manner,  l o a d e d h i g h enough  entire  These s t o n e s were depth of  full  scale)  above the  the l o a d i n g could s t a r t .  was n o t d o n e o n t h e b a s i s o f Therefore,  all  broken mass.  p l o t s were  After  This the  point  (5 f t . ,  cummulative weights  made on t h e b a s i s o f  With the a p p l i c a t i o n of  were m o d i f i e d .  model,  intervals  r e q u i s i t e amount o f  i t was u n l o a d e d and a l l  pro-  highest  Five  further scoops  diagrams c o v e r i n g  the  full  swell  scale). it  is  Plotting  erroneous.  drawn o u t o f factors,  the  these  plots  S e c t i o n 5.4.  h a v e b e e n drawn f r o m  the marked stones were  buckets the  volumes  under  pull-  in  because  appropriate  is e x p l a i n e d  of  and  The b l a s t i n g was s i m u l a t e d by  then p l o t t e d on s e c t i o n a l  t h e model a t 2 i n .  x  the  to  w e r e drawn a t a t i m e and m a r k e d s t o n e s w e r e p i c k e d a s t h e y a p p e a r e d tunnel.  2 in.  The o r i g i n was moved s o m e -  t h e model was  20 i n c h e s ,  dimen-  red c o l o u r e d marked s t o n e s  its origin  the d r i f t .  l o a d i n g was  l a y e r was p l a c e d u n t i l  4,200  of  tests  three  i n t e r f a c e had a g r i d  s y s t e m had  longitudinal  The p r o c e s s o f  a capping of  ing at  to the  dipping  Each s u c h  scale).  the purpose.  t h e model a n d 12 i n . times  full  be  t h e o r e m a t e r i a l by s p r e a d i n g 2 i n .  sional  2  could  V.  a t a t i m e and t h e n p l a c i n g m a r k e d s t o n e s on a s p e c i a l interface.  drift studied,  so as a r e c e s s  layers  at each  the  s l a s h was n e e d e d t o be  F.W.  along  recovered  for  the reuse.  kk.  O r e m a t e r i a l was p r o p e r l y  mixed a g a i n ,  was made on t h e m a t e r i a l b e f o r e  the next  S i d e s l o p e s made up o f level  stopes  dinal  stopes,  efficient shown  and a l s o  the o r e .  the f r i c t i o n  are almost equal  4.51  plywood  to  Tests  required, t e s t was  boxes  and H.W.  b o t h were c o v e r e d w i t h  as f o r  that  t h e F.W.  if  testing  performed for  hand v i b r a t o r  model was a c h i e v e d by hole  into  A blast of  the h o l e  to get  behind  was v i b r a t e d h i n d and  Column o f  normally until cedure drawn.  pushing  plate.  detailed  paper  Ore: the column of o r e The  5.k.  block with  sections  to j u s t  between of  plate  layers at  under  above  loading of  20  blast  retreat  plate  above  and t h e  the  plexiglass  to keep  in b a l a n c e as the of  the  level  the b l a s t  From t h e r e  on,  t h e model was  Thereafter,  r e p e a t e d and s e c t i o n a l  be-  loading  up t o  p l a c e d on g r i d  end  course,  Ore m a t e r i a l was p l a c e d  it  drift  distance.  the b l o c k and, of  i n c h e s was a c h i e v e d .  S e c t i o n k.5 was  the  2 inches.  and m a r k e d s t o n e s w e r e  least  by means  t h e same s h a p e as t h e  the b l a s t  had been v i b r a t e d  p l a t e was p u l l e d o u t .  a capping of  co-  have  r o c k on r o c k and r o c k on s a n d  in S e c t i o n  a wooden  The o r e  the b l a s t  When t h e o r e  in 2 i n .  longitu-  t h e same f r i c t i o n  had t h e same s h a p e a s t h e b l a s t , was p u t  in v e r t i c a l  the b l a s t  as d e t a i l e d  O r e was f i l l e d  in f r o n t of  continued. then  block.  the b l a s t  sub  by S w e d i s h e x p e r i m e n t e r s  t h e same d i s t a n c e as t h e d e s i r e d  p l a t e , which  the d r i f t  test  0.7-  Tests With Vibrated  a small  transverse  p a n e l s meant t o e x p e r i m e n t  A few c h e c k t e s t s w e r e made by v i b r a t i n g of  factor  performed.  for  sand paper  coefficients  and a s w e l l  plate  loaded  intersections the  diagrams  prowere  45. 4.52  only. the  Ore and W a s t e  Tests:  Ore and w a s t e  t e s t s were  In a few t e s t s ,  top o f  panel  from the  H.W.  F.W.  or  were c o n t i n u o u s l y V.  Figure  for  a 30'  with 55° or  H.W.  the d e s i r e d  14 shows orebody  angle. side of  s i d e of  drifts  the d r i f t  15  for  a r e shown  a r e shown on t h e s i g n  drift  shows a 50  scoops  scoops from  Appendix  on two  levels stope  wide orebody  drawn e i t h e r  placed  in  either  events  longitudinal  ft.  the  i.e.,  the sequence of  a single  a n g l e and F i g u r e  c u m m u l a t i v e number o f  the  loading sequence,  these p i c t u r e s  on t h e same l e v e l  As  band was v i e w e d  Photos o f  stope with  purpose  d o l o m i t e was p l a c e d on  the b l a s t .  this  the proper  Two s e t s o f  F.W.  shape o f  drift.  a longitudinal  a t 65°  The  the  the d e m o n s t r a t i o n a l  white  the flow of  to determine  taken.  two e x t r a c t i o n F.W.  of  from the bottom d r i f t ,  front plexiglass  for  a 2 i n c h w a s t e band o f  the contours  w e r e drawn  performed  at  from the  in f r o n t of  F.W.  the  mode 1 .  Triaxial  4.6  Compression T e s t i n g  These t e s t s were performed obtained  from one p a r t i c u l a r A number o f  techniques. axial  shear  tests, s i z e of  For  etc.  4-in.  compacted s a m p l e s ,  equipment.  However,  flowability  its  shear  tester,  testing  availability  at  (A m i x t u r e o f diameter  this  cell  a vibrator  of  ore  samples  in the mine.  A triaxial  the sample t e s t e d . for  the  t e s t i n g machines are a v a i l a b l e  mainly because o f  A cell  to study  place  For e x a m p l e , d i r e c t tester,  Equipment:  ring  in the s o i l shear  tester  testing and  m a c h i n e was u s e d f o r the U . B . C .  fines  to  1/2"  laboratories crushed  s a m p l e s was u s e d as t h e t e s t i n g  permits was u s e d  t h e use o f  standard  to c o n s o l i d a t e  the  Triabove for  the  rock.) equipment.  compacting  the s a m p l e . Samples  46. up t o a maximum g r a i n test  s i z e of  3/4 i n c h may be t e s t e d ,  s p e c i m e n s a r e more r e a d i l y  inch s i e v e  size,  u s e d was 8  obtained  B i s h o p and H e n k e l  if  the  although  limit  ( 4 1 ) . The h e i g h t  satisfactory  is placed at of  the  test  the  3/8  specimen  inches.  Figure  8 shows  the p i c t u r e s  of  the  test  s p e c i m e n and t h e  testing  equipment. It have  1.  the  c a n be a r g u e d  following  time a t e s t  A new s a m p l e h a s because a large data.  (In  Errors (Up  4.  itself  particularly  the  reasons of  may n o t  be  obtained  repeated.  t o be f o r m e d e a c h t i m e . number o f  a range o f  tests  have  This  factor  t o be p e r f o r m e d  Ring Shear T e s t e r ,  confining  the use o f  pressures,  rubber  is  important  for  complete  any o n e  sample  etc.)  membrane a r o u n d  -  need t o be a p p l i e d due t o  especially of  important  1 P.S.I.  his  because of  the s t o p e s .  use o f  This  in J e n i k e ' s  mass-flow bins with  range o f  work.  is  corrections  the o u t l e t  narrow  u s e d as a b o v e may  the  sample.  P.S.I.)  Appropriate  near  equipment  c o m p a c t i o n and u n i f o r m i t y  c a u s e d due t o  t o 0.6  sample  testing  the case of W a l k e r ' s  may be u s e d f o r  3.  triaxial  limitations.  Required degree of every  2.  that  near  small  the  low p r e s s u r e s  aspect  analysis,  outlet  the o u t l e t  a low and s m a l l  the weight  direct  to  in which c a s e ,  and t h i s  be  tall  have p r e s s u r e s  i s one o f  shear  the  existing  has been n o t e d  openings  of  tester  and in  the main for  design  PICTURE I. Sample ready for testing  PICTURE 2. Failed sample  PICTURE 3. Triaxial cell under loading (assembly)  FIGURE  8.  TRIAXIAL  TESTING  EQUIPMENT  48. However, size,  in the case of  this  error  the preceding range of  2 of  Equations  or  Observations in Table  may n o t  6 P.S.I.  mass-flow,  Stopes w i t h  comparatively  be v e r y s e r i o u s ,  3 (12) and 3 (14) t h a t  t o 30 P . S . I .  made and r e s u l t s o b t a i n e d III  and  it  in Chapter  5.  opening  c a n be s e e n  pressures  d e p e n d i n g on w h e t h e r  f l o w on t h e s i d e s l o p e s ,  Appendix  and  larger  it  is  from  are  in  a  free  the  etc.  from these  tests  are  presented  49. CHAPTER 5 TESTS DESCRIPTION PROCEDURES & R E S U L T S .  G e n e r a 1:  5. 1  The  t e s t w o r k was s t a r t e d w i t h  i n t h e open mass.  Cave f i g u r e  the study of  determinations  the cave f i g u r e s  i n o p e n mass mean t h a t  model was f i l l e d w i t h o r e m a t e r i a l and m a r k e d s t o n e and was w i t h o u t structions  a g a i n s t a f r e e development of  other words,  These t e s t s  4.5.  the d i f f e r e n t tance for  tests  but  the  is  sufficient  in the  that  Therefore, layouts  of  render  level  it  caving  thesis. al  every  sub  work o f  first  suitable for  Instead level the  of  caving 'A'  Loading  caving  tests,  sub  level  this  a few t e s t s w e r e p e r f o r m e d sub  level  of  impor-  cave  caving method, studies  T h i s was  contact  in o r d e r  observed  is  and  it  faster  in the  a few m o d i f i c a t i o n s w e r e done w i t h t e s t i n g of  b e i n g the main a r e a of  t e s t i n g every  the  possible configuration  is generally  for  the  of  plan-  sub  this  longitudin-  to check the  n a r r o w and s t e e p l y  the  t h e model  longitudinal  investigation  more e m p h a s i s has b e e n g i v e n  ore body, which  to check  c a v i n g w h i c h h a v e been u s e d  the comprehensive  layouts,  such  such cave f i g u r e s  possible configuration.  Sec-  studies  fundamental  One s e t o f  the t r a n s v e r s e  in  mass.  Thereafter,  layouts,  In  t e s t s w h i c h w e r e c o n d u c t e d by us b e f o r e ,  the broken  the t r a n s v e r s e  n i n g work a l r e a d y . to  level  flow.  t h e p a r t i c l e movements a l o n g t h e H.W.  rest of  figures.  the s o l i d g e o m e t r i c a l  the g r a v i t y  to study  sub  almost with  in doing  the ob-  the d r i f t .  t h e f l o w and t h e y a r e a l s o o f  t h e p r e l i m i n a r y model  was o b s e r v e d than  sequences of  longitudinal  are e s s e n t i a l during  are useful  ore  any  and s e c t i o n a l d i a g r a m s p l o t t e d as d e s c r i b e d  the u n d e r s t a n d i n g of  figures for  f l o w and c a v e  no s i d e s l o p e s w e r e p l a c e d on e a c h s i d e o f  was done f r o m t h e d r i f t tion  gravity  in  dipping  design  50. (widths  range approx.  The  o r e body  'A'  the procedures  between  i s one o f  of  1 5 ' t o h0' and d i p s v a r y b e t w e e n 65°  the  first  5.2  configuration  Description of  at  of  t h e Model  These comprised of  lk", 79° and 8 4 ° .  in order  these were  found  the a n g l e of  that  this  other  angle  a close  range of  t e s t w o r k c o u l d be t a k e n up f o r be r e q u i r e d  79°  A total  of  eleven  the  tests  covered  side slopes.  Tests  side  Two o f  size  79°.  the above  slopes  tests  is  the were  error;  i n t h e o p e n mass  It  distribution  was  5° a b o v e and b e l o w  performed  i s b e t w e e n 75° -  is a f u n c t i o n of  layout.  tests  t o e v a l u a t e any d i s c r e p a n c i e s due t o p e r s o n n e l  sliding  any  t o c h e c k any  i n t h e o p e n mass and t e s t s w i t h  Therefore,  accur-  Tests:  t o be n e g l i g i b l e .  that  After  Caving Method:  tests  standard adopted p a t t e r n of repeated  few a r e a s on t h e m i n i n g p r o g r a m .  the time i t w i l l  Transverse Sub-Level done.  80°).  t e s t i n g and i n t e r p r e t a t i o n w i t h i n  acy have been e s t a b l i s h e d , e x t e n d e d particular  to  realized,  indicate  however,  i n t h e b r o k e n mass and  factors. Longitudinal  completed f o r  Sub-Level  t h i s method.  i n g between f o o t w a l l  Ore body w i d t h s  angles of  the f i r s t  tried.  For  contact  and draw c o n f i g u r a t i o n s  place  the d r i f t  70°.  These r e s u l t s  footwall  slash.  well  Caving Method:  55° and 75° w i t h  few t e s t s ,  into were  of  the e x t r a c t i o n were s t u d i e d .  the f o o t w a l l compared w i t h  Quite encouraging  Twenty-six tests 20',  30',  Later,  where f o o t w a l l similar  been  k0' and 50',  increments of drift  have  5°,  was p l a c e d  vary-  have in  footwall  i t was d e c i d e d a n g l e s were  been  to  less  than  l a y o u t s w h i c h had u s e d no  r e s u l t s were o b t a i n e d w i t h  this  improve-  ment. B a s e d on t h e a b o v e c o n s i d e r a t i o n s ,  the  test  p r o g r a m was  evolved.  51 A total  of  programme.  5.3  thirty-seven General  Test  A.  B.  tests,  breakdown o f  2.  i n c l u d i n g on  the t e s t s  1:20  i s as  TRANSVERSE  SUB-LEVEL  Cave f i g u r e  tests  2.  Test with  74°  side  slopes  -  central  Test with  74°  side slopes  -  alternate  loading.  3.  Test with  79° s i d e s l o p e s  -  alternate  loading.  4.  Test with  84°  -  alternate  loading.  side  LONGITUDINAL S U B - L E V E L  20  i n open m a s s .  slopes  CAVING T E S T S :  Footwal1  ft.  Angles:  60°,  30 f t .  60°,  40 f t .  50  55°,  ft.  loading.  Footwal1 no  65°  90°  slash  65°  85°  slash  65°  80°  slash  65°  75°  slash  no  slash  80°  slash  no  slash  80°  slash  80°  slash  65°,  60°,  55°,  20 f t . (1:20 scale  Some o f check  the e f f e c t s  the of  Slash:  65°  75°  65°  70°  slash  (in 5.  enti  follows:  1.  65° 4.  the  CAVING T E S T S :  65° 3.  s c a l e covered  Program:  Orebody W i d t h : 1.  one  65°  drift  80°  'A')  slash  test)  tests  mentioned  different  in  'A'  S 'B'  ore m a t e r i a l , swell  above were factors,  repeated loading  to pattern  52. and t h e e f f e c t distance,  consolidating  by means o f The  but were  of  from the p r e v i o u s  Testing After  cription studied  screen  not  tests  the  4.5,  using e x i s t i n g  depending the view  is  in that  gravity  h a s an i m p o r t a n t total  that  the  l o a d i n g t h e model  was  percentage of  Considerable In o r d e r  of  the e x t r a c t i o n  direction.  It  drift,  was f o u n d  f l o w changes w i t h  because  that in  blast  and t h e v o i d s  proper  swell  the draw  is considered,  figures and  in the b u l k  in the b u l k ) .  the o r e  factors  effect  retreat  do  the  could  dis-  consolidation  t h e model  the change  was  upon  the  the m a j o r i t y  cave  b a s e d on t h e draw f i g u r e s .  t h e use o f  of  voids  des-  consolidation to study  a particular  b e a r i n g on t h e c a l c u l a t i o n o f  interpretation It  manner.  to  The  a vibrator.  c o l u m n and t h e muck i n t h e b u c k e t o f  proper  order,  obtained  in a p r o g r e s s i v e  T h i s was done on t h e a s s u m p t i o n t h a t  extractions  became a p p a r e n t ore  used.  column f o r  ( d e r i v e d from the s p e c i f i c g r a v i t y  and t h e  aspect of  upon how t h e o r e m a t e r i a l was f i l l e d that  information  test  facilities.  being  the broken ore  in the d i r e c t i o n face  i.e.,  p a c k e d and p a c k e d o r e m a t e r i a l , d e p e n d e n t  the m a t e r i a l  t a n c e was v i b r a t e d .  free  retreat  sequence or  been c o m p l e t e d , a c c o r d i n g  the p a r t i c u l a r  loosely  of  consolidation,  place  i n any p a r t i c u l a r  the next  had a l r e a d y  be a c h i e v e d by p a c k i n g by means o f of  blast  Procedure:  and t e s t e d ,  analysis  out  was u s e d f o r  a few t e s t s  in  carried  the e l i m i n a t i o n p r i n c i p l e ,  in Section  t e s t e d both  ore over a desired  vibrator.  t e s t s were  done a f t e r  5.4  a  column o f  takes  of  the  change  confirmed density This  recoveries,  aspect  dilutions  From t h e f o r e g o i n g , for  the choke  blasted  a scooptram are  important  for  it  the  figures.  therefore,  that  a model  l o a d e d w i t h o r e and w a s t e  53. material  without  no b e t t e r  purpose For  obtained  recoveries,  realistic  consolidations  than being a v i s u a l  the above  draw f i g u r e s centage  proper  reasoning,  waste d i l u t i o n s For  were dropped  intensity  with of  and t o t a l  are o b t a i n e d ,  marker g r i d  every c o n f i g u r a t i o n  A few  stones  After  is  consistent.  Further,  c o u l d not ore,  and  mass,  final  its  description  (a  r a t i o of  the c o n d i t i o n s  procedure,  will  be u n in  point and  the of  loading  section  diagrams  i n S e c t i o n 4.5, i n t h e  case  column o f  i t was f o u n d  ore  that  (Section t h e use  this  the a c t u a l the  method  not  still  b l a s t e d column  results.  of  of  Therefore,  these  procedure.  however,  evolved  after  the above  experimenta-  follows,  t h e model was done w i t h in  f r o m t h e F.W.  or  ore material o n l y ,  the e n t i r e  S c o o p s w e r e drawn w i t h  muck drawn  s o m e t i m e s g u i d e d by  of  interpret  Marker s t o n e s were p l a c e d  in each t e s t .  tests  by means o f  the v i b r a t e d  a few t e s t s ,  a r e needed to  The  vibration.  etc.,  per-  i n S e c t i o n 4.3.  as d e t a i l e d  c o n t i n u e d as a r e g u l a r  Loading of  illustrative  t h e c o n s o l i d a t i o n s o b t a i n e d by  fully  and c o r r e c t i o n s not  the  c o n t r o l l a b l e and t h e c o n s o l i d a t i o n s o b t a i n e d a r e  represent  t e s t s were  tion  not  b a s e d on  studied.  the completion of  the v i b r a t o r  serve  the c a l c u l a t i o n of  extraction,  therefore,  T e s t i n g was c a r r i e d on w i t h 4.50-  analysis  time consuming from the s o r t i n g  t e s t s w e r e done a s m e n t i o n e d  the help of  would  only.  used as s u c h f o r  from the program.  Draw f i g u r e s  regions  t h e same r e a s o n , o r e and w a s t e t e s t s  model, which are a l s o extremely view,  aid  respective  any q u a n t i t a t i v e  from the t e s t s  and m i s l e a d i n g .  in the  volume o f  the d e s i r e d  t h e H.W.  of  the  loading  the d r i f t ) ,  t h e w a s t e band l a i d on t h e t o p o f  without  any  loaded intensity  w h i c h was  the o u t l i n e of  the  5h. actual  shape of  the b l a s t .  cation of  proper  culations  for  ore  as c o n s i d e r e d  c a u s e d by further  (Section  t h e w o r k done a t M t .  factor of  is used f o r  1.10  t h e e x p a n s i o n when a r i n g such t h a t  factor  between  intermediate swell  factor  i s an  In o r d e r  to d e r i v e  scoop bucket used f o r  actual It  bucket  m a t e r i a l used  is  less  fragmentation  coveries  calculations field loaded  of  Cal-  a r e made  extractions  observations,  swell  c a l c u l a t i o n work.  It  is,  swell is  factor  1.37-  o r e , which  is  1.5, b u t  In draw  a  the  control,  the ore m a t e r i a l  from the v a l u e of test  (see T a b l e  factor of swell  swell  a c t i o n of  the  factor  1 S IA,  factor of  in  conducted.  1.37 u s e d f o r  of  the  Appendix the  Il).  heaped  1.5 b e c a u s e  of  the scoop over a wide  that  the computed v a l u e s o f o r e  W i t h some p r e l i m i n a r y have been d e r i v e d  in s i t u  however,  is  is e x t r a c t e d ,  a r e as good a s t h e a s s u m p t i o n s made i n  factors  a con-  point.  factor.  i n t h e model and t h e  When t h e o r e  that  variable.  the d i g g i n g  i n t h e draw  the swell  1.5  than the o v e r a l l by  is noted  a few e x p e r i m e n t s w e r e  in any swell  (50), i t  factor of  testing,  s h o u l d be m e n t i o n e d h e r e  and t o t a l  fired.  an o v e r a l l  swell  in s i t u  c o n s o l i d a t i o n brought about  It  in use.  extractions  the b l a s t e d column of  1.10 and  i n t h e model  then that  i n the mine  range o f  and t o t a l  Isa,  important  this  t h e model  is  f o u n d was n o t much d i f f e r e n t  c a n be s a i d ,  the m a t e r i a l  appli-  Factor:  expansion occurs  value  5-41) o f  the  5.43.  intermediate swell  The  volumes were c o r r e c t e d w i t h  recovery, waste d i l u t i o n s  On r e v i e w i n g fined swell  factors  in S e c t i o n  Swell  5.41  swell  Extraction  swell  factor  known t h a t  of  experiments  for  the broken  the  loaded bucket  t h e r e a r e not  very  rethe and.  rock for  precise  >  means a v a i l a b l e y e t materials.  It  for  ore  region  the  has been o b s e r v e d  lar material dilates column  finding  in s i t u  by v a r i o u s  as f l o w e n s u e s .  i n t h e model  faster this  i n t h e upward d i r e c t i o n  account a l o n e ,  total  extractions  happen  in  can be p r e d i c t e d  show h i g h e r  values  a particular  SCOOP FACTOR  For  blast  draw  of  proceeds  i n t h e model and on and  t h a n what w i l l  thereby actually  retreat  t h e number o f  for  buckets to  d i s t a n c e has b e e n c a l c u l a t e d as  X  be  drawn  follows:  I n - s i t u S . F . of the muck i n t h e h e a p e d bucket.  simplicity,  scoop f a c t o r s  comparison purposes  figure will  have  the heaped b u c k e t  generally  cu.ft.)  b a s e d on t h e a b o v e h a v e been  throughout  t o be a d j u s t e d  (112  the c o m p u t a t i o n work.  in actual  outside of  practice since  the o r e  and w a s t e  In  used fact,  the o u t l i n e inter-face  in  stope.  5.43  C a l c u l a t i o n Procedure for  Ore  Recovery  and T o t a l  Extractions:  The v o l u m e s o f o r e and w a s t e , w h i c h a r e c o n t a i n e d by c a v e of  ore  =  t h e draw v o l u m e s t a y s the  that  to the depth  i n t h e model  the  granu-  the b l a s t e d column  that waste d i l u t i o n s  a scoop f a c t o r or  Volume o f  this  of  i n t h e model  I n - s i t u volume o f rock b l a s t e d f o r the b . r . d . under i n v e s t i gation.  purely  consolidated  Factor:  From t h e a b o v e , for  relation  granular  c o n s o l i d a t i o n of  than that  also  that  the  the m i n e .  Scoop  5.42  it  in  f a c t o r of  workers  Now t h a t  i s much l e s s  i n t h e s t o p e and i t was o b s e r v e d  swell  different  total  extractions  h a v e been e s t i m a t e d f o r  different  figures  sizes  of  of  56. blasts. volume  S i n c e the cave integration  Instead,  figures  and c o n s e q u e n t l y  the volumes o f  formulas,  are unsymmetrical,  by w h i c h  no r o t a t i o n a l  the cave f i g u r e s  the areas of  very  it  i s not  possible  use  s o l i d c o u l d be e s t a b l i s h e d .  w e r e e s t i m a t e d by u s i n g  thin  to  s l i c e s of  the s o l i d  prismoidal  figures  are  measured. Figure total ore  extraction  the procedure  In a g e n e r a l  x = y  in F i g .  Test  5-5  Ore  recoveries,  II.  when t h e S . F .  total  It  extractions  i n S e c t i o n 5.^3 f o r  i s not  These a r e  S.F.  of  c a s e , when  than  the  the e n t i r e  rest  the  of  mass i s  the  t h e same  accordingly.  in the e x t r a c t i o n  p o s s i b l e to discuss  Table  sub  all  also  here but  in the above  i n c l u d e the  calcu-  intervals  1 and T a b l e  the t e s t s  appropriately  1 and I A ,  level  in Table  and d i s t u r b a n c e s w e r e o b s e r v e d However, cave f i g u r e s  draw w h i c h  Due t o  a range o f  are  intensity  and  IA  in  t h e most  tables of  for  loading  drift.  Hang-ups from the model.  and w a s t e d i l u t i o n s  tabulated  o n e s h a v e been g r o u p e d  comparison purposes.  is  represented  the p r o b a b l e  f a c t o r of  the v i b r a t e d  values of  the  were  in the s p e c i a l  and has a d i f f e r e n t  i.e.,  distances.  representative  pattern of  etc.,  recovery,  Results:  retreat  Appendix  case,  the c a l c u l a t i o n o f o r e  9, c a l c u l a t i o n s a r e m o d i f i e d  l a t e d as d e s c r i b e d blast  for  and w a s t e d i l u t i o n s ,  c o l u m n h a s been v i b r a t e d  mass. or  9 shows  results  repeated with  ore  in the proposed  inconsistencies  c o l u m n i n some o f  factors  s c o o p i n g t h e muck  a r e drawn up a f t e r  m i g h t show v a r i a n c e .  swell  during  the  layout  general  drawings.  in the d e t e r m i n a t i o n of the For  tests, this  the  calculated  r e a s o n , a few  d e t e r m i n e d as c a r e f u l l y  swell  as was  tests  possible  57. ORE ZONE A  WASTE ZONE B  SECTION  ORE PACKED WITH VIBRATOR  VOLUME 'C  0' A TYPICAL SECTION ALONG THE  ORE RECOVERY  10'  15' 20' 25' 30'  CENTER OF THE EXTRACTION DRIFT  Volume C T X  %  TOTAL EXTRACTION WASTE DILUTION  5'  x 100 = O  r  (Volume C -fx ) + (Volume D-ry) x 100 = T.e V Volume D-i-y x 100 = W, (Volume C-rx)+( Volume D-ry)  % %  WHERE a = BLAST RETREAT  DISTANCE UNDER STUDY  b = x-a (VIBRATED COLUMN OF ORE ) V = IN SITU VOLUME OF THE ORE BLASTED IN THE BLAST DISTANCE OF 'a'  FIGURE  9.  CALCULATION TOTAL  PROCEDURE  FOR  E X T R A C T I O N AND W A S T E  RETREAT  ORE RECOVERY, DILUTION.  58. within  the p r a c t i c a l  widths  of  ore  recovery,  the  total  results  information  extraction  but  It  Before are  1 & IA  for  F.W.  of  angle  the c a l c u l a t e d  ll),  various  the problem of  orebody  values  etc.  (Appendix  importance of  remains yet  it  c a n be  layouts  or  said useful con-  properly  scaling-up  regard  to the actual  the stope w i t h  the ore  extractions.  information tests,  A further according  representative  33 a n d 32 f o r  5 5 ° and 70°  and w a s t e d i l u t i o n ,  relative  c a n be f o r e s e e n ,  f r o m t h e model  tions  a n g l e and 50' a t  the Table  the behaviour  and t o t a l  r e v i s e d a s more  areas.  the  there  to p r e d i c t  recoveries  of  3 7 , 36, 31,  o b t a i n e d f r o m g e o m e t r i c a l l y s c a l e d model h a s g i v e n  regarding  figurations, results  numbers  c a n be c o n s i d e r e d most  From t h e s t u d y that  Tests  2 0 ' , 3 0 ' , 40' a t 6 5 ° F.W.  respectively of  range.  that is  these figures  learned about  and f r o m a c t u a l  modification of  to the grade  will  have  draws  t h e draw v o l u m e w i l l  t h e d i s c u s s i o n on t e s t s  is  constantly  t h e draw c h a r a c t e r i s t i c s ,  controlled  in the s t o p i n g  t o be  i n t h e sub  both  level  change t o t a l  cave  extrac-  area. started,  the f o l l o w i n g  notations  described.  1.  #,  i n t h e d i s c u s s i o n on v a r i o u s  Table 2.  1 or  IA  Recommended l a y o u t are presented  3.  in Appendix  Configurations patterns  to  V, 'H'  b a s e d on T a b l e  to s e r i a l  V,  Appendix  in  Appendix  5.61  20 f t .  the  results  IV.  in Appendix  D i s c u s s i o n on t h e L o n g i t u d i n a l width.  number  II.  5•6  Orebody  refers  p a r a m e t e r s b a s e d on t h e a n a l y s i s o f  in Table 'A'  tests  IV  show p r o p o s e d  layout  IV.  Sub L e v e l  Caving Tests.  1  59. 5.611  A t 60° #1 a t  F.W.  a n g l e @ 60 f t .  7' b . r . d . ;  no F.W.  #2 a t 7' b . r . d . ;  than even  t h e H.W. was  Contact  rilling  total  is  less  than  narrow o r e b o d i e s were  =  59-5%  Te  =  O  =  85.0.  Te  = 134S.  is erroroneous  r  F.W.  slash.  because the  Te  top w i t h  no m a r k e r s  shown on t h e s e c t i o n a l This  100..  and f l a t t e r  error  angles.  in  removed by p l a c i n g t h e m a r k e d s t o n e s  i n #1  show  it.  So a p a r t  possibly  chances of  much b e y o n d  appear this  the  along  and l a t e r ,  waste  of  d i a g r a m s and h e n c e ,  can q u i t e  However,  83.  increased flow  t h e m a r k e d s t o n e s much f a s t e r  in from the v e r y was n o t  Or  O r improves w i t h  removed a l l  extraction  l a t e d Te  This  100..  slash;  80° F . W . s l a s h ;  C o m p a r i n g #1 & #2; less  S.L.I.  the  calcu-  with  occurrence  top o u t l i n e of  the  blast.  5.6121  At  65°  F.W.  60  angle,  b.r.d.  slash  Or  =  #13, 8 5 ° F W.  slash  0  r  8 0 ° F.W.  slash  0  r  #4,  9 0 ° F.W.  recoveries,  the d r i f t  ft.  = 71 .0%  no F.W.  slash  Comparing the above,  t h e F.W.  @6  S.L.I. 0v  #3>  #6,  ore  ft.  but  s l a s h of width  the waste  rock.  though  8 5 ° F.W.  it  ore  recovery  =  ,  Te  = 146.  = 84.6.  ,  Te  =  138.  =  ,  Te  =  128.  86.6.  82.6.  production while  drill  the  jumbos s u i t  best  best  to  k e e p i n g a minimum p o r t i o n  Therefore, produces  slash gives  layouts with  slightly  lower  80° F.W.  Ore  that  total  extractions  recovery  a r e b a s e d on an a s s u m e d a v e r a g e  used f o r grade of  any the  of  slash  slash.  s h o u l d be m e n t i o n e d h e r e  comparison of  Te  t h a t 9 0 ° F.W.  80° to the h o r i z o n t a l ,  (#6) c a n be s e l e c t e d e v e n  It  shows  s p e c i f i c a t i o n s of  into  compared t o 90° o r  it  130.  ,  60. orebody. high or  However,  low g r a d e o r e Now,  23,  24) a t  ies  and t o t a l  b.r.d.  60 f t .  At  #15 a t  27  #20 w o u l d d i c t a t e  F.W.  @ 45  angle  @ 8 0 ° F.W.  slash  recoveries  and t h e y  45  Therefore,  is  in the c a s e o f  developing ore  F.W.  T e s t No.  and t o t a l  that  best ore  recoverft. para-  a r e c o m p a r a b l e t o #20 a s d i s c u s s e d  ft.  S.L-I-  65°  shows  2 0 , 2 1 , 22,  S.L.I.  #26 a t 6' b . r . d .  At  it  37 (#19,  the s e l e c t i o n of optimum l a y o u t  slash  the s e l e c t i o n of  coveries  slash,  ft.  i s more e c o n o m i c a l  5-6123  orebody.  a r e o b t a i n e d on a c o m p a r a t i v e b a s i s , a t 8  b u t a 60' S . L . I ,  rently  the  (#5, 6) a n d T e s t N o .  @ 8 5 ° F.W.  it  of  to  S.L.I.  5-6121.  t i p l e of  portion  7' b . r . d .  good o r e  Section  No.  and 8 0 ° F . W .  extractions  65°  w o u l d h a v e t o be a d j u s t e d a c c o r d i n g  in any p a r t i c u l a r  S.L.I,  Therefore,  5.6122  extractions  comparing Test  m e t e r s a t 60 f t .  give  total  angle &  30 f t .  and T e s t  It  interpret  to  extractions,  fore,  preferable.  the  Granduc o v e r a l l  45 f t .  practical  in the s i m i l i a r  to s a t i s f y  compared w i t h  other  c a n be a p o s s i b l e  restraint  layout  conditions. of  development  either  parameter  Further,  30 f t .  program  or  in the  mul-  cur-  block.  28 (#17)  is easy  S.L.I,  in  a higher  & operational  From S e c t i o n s  or  S.L.I. No.  60 f t . that sub  37 (#27, S.L.I,  for  level  28, 29) show in t h e i r  low o r e  respective  t h e same p e r c e n t a g e o r e interval  considerations  5-611, 5-6121, 5-6122  which  is  tests. recovery  compatible  i s more e c o n o m i c a l a n d ,  and  5-6123, #20  re-  in Table  with  there-  1  is  61 . the s e l e c t e d  layout.  It  ( T a b l e 5) b o t h g r o u p e d  5.62  30 F t .  5.621  At  shown a s C o n f i g u r a t i o n  under Appendix  Orebody  6 0 ° F.W.  is  A and S e r i a l  No. 1  IV.  Width:-  angle,  60 f t .  S.L.I.  & Loading  Intensity  = H . W . : F.W.::1:3 T e s t No.  9 (#34, 3 5 , 36, 37, 38 and 3 9 ) , w i t h  on a c o m p a r a t i v e b a s i s ever, be  that  i t was f o u n d w i t h  improved w i t h  5.622  65°  At  the  F.W.  60' S . L . I ,  further  testing  i n t r o d u c t i o n of  angle,  60  ft.  S.L.I.,  How-  recovery  values  &8  b.r.d.  can  slash.  no F.W.  slash  ft.  ; 0  r  = 54.7.  Te = 1 1 0 .  #40, l o a d i n g  intensity  = H.W.:F.W.::1:1  ; 0  T  = 81.0%  Te =  l o a d i n g f r o m t h e H.W.  figuration At  B  (#49, 65°  Loading  60  Intensity  and t h e r e a f t e r ,  IV)  about  side at  Section  angle,  alternate  draw f i g u r e s  i s brough  l o a d i n g on t h e F.W.  that  loading  is  better  113.  than  ex-  side.  J & K (Appendix  t h e draw f i g u r e  only  a F.W.  ore  the b e s t .  = H.W.:F.W.::3:1  Configuration  5.6221  that o v e r a l l  is  shows  intensity  A comparison of  of  b.r.d.  slash,  #41, l o a d i n g  The a b o v e shows c l e a r l y cessive  and 8 f t .  no F.W.  representing  respectively.  by a F.W.  #41 and #40 i s shown  A further  improvement  s l a s h and an i n c r e a s e d  the s t a r t of  loading.  This  is  by of  intensity  shown by  Con-  5-6221). ft.  S.L.I.  = First  alternate  & 80°  F.W.  slash.  90 s c o o p s a r e drawn f r o m t h e  loading  i s done f r o m e a c h s i d e o f  F.W. the  side drift.  62. Test best ore  No. 36  recovery  (#47  t o #52)  and l e a s t  shows  total  that  8 ft.  extraction with  b.r.d.  (#49)  the above  renders  layout  the  para-  meters .  5.6222  At  65° F.W. a n g l e , 45 f t . S . L . I .  T e s t No. b.r.d.  36  (#53,  compared to e i t h e r a 5 f t .  5.6223  At  better  T e s t No.  than 5 f t .  recoveries  or  and h e n c e  T e s t No.  figuration  5-623  it  'sub  level  ferable. is  intervals' Therefore,  40 f t .  5.63I  At  =  (#59, and 60'  Orebody  6  ft.  80°  F.W.  slash.  show t h a t b . r . d . 30 f t .  S.L.I,  of  6 ft.  gives  low  is ore  layout  3 ( T a b l e 5)  60, 61, 'blast S.L.I,  p a t t e r n , which  in Appendix  i s seen  that  i s shown a s C o n -  IV.  slash.  62,  63 and 64)  retreat a t 8'  distance'  b.r.d.  F and S e r i a l  indicate thatout  of  c o m b i n a t i o n s , #60  is acceptable.  No. 4 i n T a b l e  5,  Proposed  both  all is  pre-  layout  in Appendix  IV.  Width:-  55° F.W. a n g l e , No F.W. s l a s h and L o a d i n g S e q u e n c e H.W.:F.W.::1:3  T e s t No. c o m p a r e d t o 45 f t . It  is better with  preferable.  the best  No.  shown a s C o n f i g u r a t i o n  5.63  &  57 and 58)  75° F.W. a n g l e & no F.W. 25  recovery  5-622, 5-6221, 5-6222 and 5-6223, i t  36 s u g g e s t s  T e s t No.  slash.  b.r.d.  But on t h e w h o l e ,  i s not  B and S e r i a l  At  or 8 f t .  (#56,  8 ft.  From S e c t i o n s of  36  80° F.W.  show o r e  65° F.W. a n g l e , 30 f t . S . L . I .  Again,  #49  54 a n d 55)  S  14 (#65 or  is c l e a r  t o #70)  60 f t .  i n d i c a t e that  S.L.I,  from t h i s  test  at b . r . d . that  if  of  30 f t . 5 ft.  no F.W.  S.L.I, or  slash  6 is  is  the  best  ft. used, then  for  63. moderately wider orebodies below)  a lower sub l e v e l  theless,  with  improved  further.  5.532  ft.  interval  t o 50 f t . )  a t low F.W. a n g l e s  with a small  b.r.d.  t h e i n t r o d u c t i o n o f p r o p e r F.W. s l a s h ,  gives  better  It  is  t o #76)  recoveries  shows t h a t 45 f t .  Never-  ore recoveries  c a n be  i n t e r e s t i n g to note here that w i t h  p l a c e o f 30 f t .  However,  this  the o p e r a t i o n , so t h e o b v i o u s at 5 f t .  to 6 f t .  b.r.d.  or better ore  5.6321  S.L.I,  at 8 f t .  increase  S.L.I,  i n c r e a s e s t o 45 f t .  in  c a n n o t be i s o l a t e d f r o m t h e r e s t  of  s e l e c t i o n w o u l d be i n f a v o u r o f a 60 f t .  e v e n t h o u g h 30 f t .  S.L.I,  o r 45 f t .  S.L.I,  i s done f r o m e a c h s i d e o f t h e  T e s t N o . 31  S.L.I,  coveries.  with  (#77,  78,  79,  S.L. Intervals 8 ft.  Therefore,  C from S e r i a l  attached  b.r.d.  the f i n a l  80,  81,  give  82,  (#78) layout  gives  83 and 84) c o m p a r e d 60 f t . , retreat  distances.  t h e maximum o p t i m u m o r e r e -  i s s u g g e s t e d by t h i s . IV  f o r t h e recommended l a y o u t s o f 20', 11.  alternate  drift.  o v e r a range o f b l a s t  No. 5 o f T a b l e 5 i n A p p e n d i x  in Figure  S.L.I,  = F i r s t 180  and, thereafter,  Configuration  is the proposed  A graph showing the c o m p a r i s o n between o r e r e c o v e r i e s extractions  to  recoveries.  s c o o p s a r e drawn f r o m t h e F.W. s i d e o n l y  45 f t . a n d 30 f t .  S.L.I.  i n F.W. a n g l e  A t 65° F.W. a n g l e , 80° F.W. s l a s h 6 L o a d i n g I n t e n s i t y  loading  to 7 f t .  c o m p a r e d t o e i t h e r o f 30 f t . o r 60 f t .  65° f r o m 55° as f r o m S e c t i o n 5.631, o p t i m u m S . L . I ,  60 f t .  is d e s i r a b l e .  H.W.:F.W.::1:3  T e s t N o . 13 (#71  equal  (55° a n d  A t 65° F.W. a n g l e , no F . W . s l a s h and L o a d i n g S e q u e n c e =  b.r.d.  (30  30'  and 40  1  layout. v/s  total  orebodies  is  100 90 80  - •—  70 rr  LU  > o o LU CC  60 50  J9 '+  40 30  *  20  *  10  •  •• / /  10  FIGURE  II.  20  30  40  50 60 70 80 90 100 110 TOTAL EXTRACTION ( % )  C O M P A R I S O N OF O R E R E C O V E R I E S / s T O T A L E X T R A C T I O N S FOR 2 0 ' , 3 0 ' A N D 4 0 ' O R E B O D I E S AT 6 0 ' S U B L E V E L I N T E R V A L , 6 5 ° F.W. A N G L E AND 8 ' B L A S T R E T R E A T D I S T A N C E v  120 130 140 150 160 20' OREBODY 30' OREBODY 40' OREBODY  65. 5.64  50 f t .  5-641  At  Orebody  5 5 ° F.W.  Loading  in D r i f t  4 ft.  in  treat  distances  Drift  A.  in D r i f t  g u i d e d by  loading.  6 ft.  Drift  uration  D from  At  Figure  No.  Intensity  T e s t No.  32 (#89,  in the case of  A and 6 f t . ,  combinations of  and 1 0 0 ) , an 8 f t . recoveries.  6 of  4 ft.  Test  in Table  layout  is  re|t  is  b.r.d.  in  Loading IV,  rock  the s t a r t  shown a s  sewas  (white of  l o a d i n g and they  A  (see  7 in Appendix  are  Config-  distances  Configuration  Calculated ore  8 ft.  and 6 f t .  B respectively. A and D r i f t  (#98) g i v e s  i s b a s e d on t h i s  and  t h e same p r o c e d u r e  5-641.  in D r i f t  E)  IV).  Exactly  Section  Drift  combination  layout  in D r i f t  33,  for  and  blast  6 - Appendix  ring at  stages of  are determined for  b.r.d.  6 ft.  combinations.  case.  a band o f w a s t e  a standard  and 9 2 ) .  No.  of  combinations of  in t h i s  Proposed  slash  9 0 , 91  b.r.d.  for  5.  (see T a b l e  retreat  - 6 ft.  Proposed  of  Table  F.W.  extractions  blast  given  and  and  separately  compared t o o t h e r  downward movement o f  70° F.W. a n g l e ,  and t o t a l  b.r.d.  A and a l s o a 6 f t .  layout  taken at d i f f e r e n t  Loading  a d o p t e d as  B,  recoveries  (#93, 9 4 , 95 and 96).  in D r i f t  15 i n A p p e n d i x V .  Serial  various  D)  IV).  and 6 f t .  recoveries  A and D r i f t  Configuration  Calculated ore  B are t r i e d  is acceptable for  P i c t u r e s were under  8 ft.  b.r.d.  p l a c e d on t h e t o p o u t l i n e  grouped  A (see  6 in Appendix  Thereafter,  A and D r i f t  the p r o g r e s s i v e  in colour)  Drift  B.  in b e t t e r ore  combination  quence adopted f o r  coveries  Drift  a combination of  this  5.642  (see T a b l e  in D r i f t  S i m i l a r c a l c u l a t i o n s a r e made f o r  B (#95) r e s u l t  Hence,  slash  are determined for  the case of  seen t h a t  F.W.  33 (#85, 86, 87 and 8 8 ) .  extractions  loading  angle,  Intensity  T e s t No. total  Width;-  From  and i s  re-  b.r.d.  for  different  B (#97, 9 8 , 99  the h i g h e s t  result  is  overall  shown as  ore  Con-  66. figuration  E from S e r i a l  In cover of  No.  the s e l e c t e d  different  depths  7 of  layout,  in D r i f t  Table  combination of A and D r i f t  b l a s t i n g w o u l d h a v e t o be d e v e l o p e d  different retreat  blast  retreat  in D r i f t  foregoing  A,  to find the f i r s t  t h e most s u i t a b l e  the e x t e n s i o n of  the e x t r a c t i o n  sliding  drifts.  the c e n t r e  the s u r f a c e of  sliding.  B i s shown  location for  if  B,  then  A.  The  less  in Table  in the case of  be a p p l i e d t o 60 f t .  (Section it  l i n e of e i t h e r  is  design of sub  draw w h i c h  7,  1  level  A logical  o r even b i g g e r orebody  in l o n g i t u d i n a l  in  rela-  cave  so as  to  observation results  from inner  f o u n d t h a t o p t i m u m maximum  drift  T h i s phenomenon  longitudinal  flow  B  3-37) s t a r t i n g f r o m t h e  B is double  the  horizon-  from the v e r t i c a l  is of  considerable  locating multiple  posi-  value  extraction  c a v i n g methods thus e l i m i n a t i n g  extension of  this  procedure  could  widths.  Slash:-  s l a s h t o be t a k e n i n t h e w a s t e  improving the g r a v i t y  1  a noteworthy  A and D r i f t  E s t i m a t e d W a s t e From t h e F o o t w a l 1 Footwall  Drift  the w i d e r o r e b o d y ,  plane of  Therefore,  in the q u a n t i t a t i v e  t h e g u e s s w o r k e m p l o y e d so f a r .  5.65  a vertical  to c e n t r e d i s t a n c e between D r i f t  a n d c a n be u s e d drifts  in D r i f t  dipping at angles  As t h e t e s t i n g p r o g r e s s e d ,  surfaces of  d i s t a n c e between  t i o n of  In any c a s e ,  d e s i g n was made by t r a n s p o s i n g d i f f e r e n t  was made i n t h e d e v e l o p m e n t o f  tal  sequence  A and D r i f t  retreat  Drift  o b t a i n e d on t h e s e c t i o n s o f  o b t a i n the best draw.  centre  proper  practice. Drift  distances  IV.  already  sides of  in a c t u a l  A or  retreat  Therefore,  is s p e c i a l l y s i g n i f i c a n t with orebodies  to D r i f t  figures  B.  B s h o u l d be k e p t a s t e p a h e a d o f  In o r d e r tion  blast  d i s t a n c e s are chosen f o r  than 6 5 ° . Loading sequence from D r i f t Appendix  5.  sub  rock f o r  level  the purpose  caving stopes  is  of  67recorded dard  b e l o w as a p e r c e n t a g e  of  the  total  ore broken  in a s t a n -  ring: Orebody W i d t h .  5.66  F.W.  Angle  20'  65°  7-8%  30'  55°  9-0%  30'  65°  5-0%  40'  55°  6.7%  h0'  65°  3-7%  50'  55°  2.8%  50'  70°  1.9%  O r e b o d y W i d t h , 65° F.W. W i t h 1:20 S c a l e M o d e l . the  test  T e s t No.  scale.  37 a t  until  1:30  cases.  The  to match w i t h by  changing  swell  group.  with  8 ft.  From t h i s  it  factor  b.r.d. is  s c a l e show a good a g r e e m e n t Barnes Implements  Forces",  made by s m a l l procedure  important  (39),  of  test  in his  of  with  results  each  taking part  in  on  1:30  this  obtained  as u s e d kept  scale.  (#30,  recoveries  in  in  similar  This  arwas  steps  31.  amongst  f r o m 1:20  1:20  t e s t was  tested material  ore  32,  33),  this  s c a l e and  1:30  other. in  technique of a bigger  a r e a s o n a b l e number o f  t e s t i n g were  From T e s t 35  paper " S i m i l i t u d e  has u s e d t h i s  was c o n d u c t e d on a  used  37)  the  the highest  that  s c a l e d models w i t h  variables  (No.  Slash.  Slash .  b a s i c parameters  the m a t e r i a l  was o b t a i n e d .  gives  clear  one t e s t  similar  the screen a n a l y s i s factor  F.W.  the parameters o f  the e q u i v a l e n t  the d e s i r e d s w e l l  60 S . L . I ,  Also,  A n g l e S 80°  work,  r e d u c e d model w i t h  achieved  in the  13.7%  scale geometrically  ranged  Waste  55°  20 f t . Tested  in both  Extra  20'  T o w a r d s t h e end o f  this  volume o f  checking the  model  times.  in the process  the S t u d i e s  than b e f o r e  This  exercise  of  Tillage  predictions and  repeated  helped  a n d , as a r e s u l t ,  show  close  the  predictions adopted  to the prototype  i n t h e mine  5.7  Discussion  5.71  A t 79° Test  model  on  side  No. 4  behaviour  work  to further  the Transverse  5.72  A t 74° From  best  7  side  t o #105)  show  recoveries  £ #104)  & 30  slope  No. 6  test  Sub L e v e l  f t . S.L.I.  r a n g e o f 7 f t . a n d 6 f t . (#103  made.  S i m i l a r approach  c a n be  advantage.  & 30  slope (#101  were  that give  Caving  blast best  Tests:-  retreat distance  o r e recovery  in the  values.  f t . S.L.I.  (#106  t o #109)  a r e t o be f o u n d  with  i s found blast  that  in this  case  also,  of 6 f t . to  retreat distances  f t .  5-73  A t 84° Test  distances  somewhat 79°  slopeas  compared  cost  slopes, though A 30  f t . S.L.I,  planning  work.  Configuration centre  t h e cave  a n d 5-73  line  6 f t . and 7 f t . b l a s t  also  t o 84°  better  which  figure  74°  o r 79°  costs  side was  tests  side  side  side  required slopes,  ore recoveries  a n d 79°  1 shows  optimum  slope  with make  of the extraction  o f draw  drift.  must  retreat  mass.  However,  a layout  with  74°  has a l r e a d y  been Serial  in a vertical  with  lower  Sec84°  o f 79°  side  used  and  side  develop-  choice  84°  found  From  pattern  i ta desirable  H from  be  t o be between  show up b e t t e r  are obtainable  pattern  angle  i n t h e open  slope.  i s shown b y C o n f i g u r a t i o n the pattern  slope  found  above, o r e recoveries  to either  This  that  of sliding,  and o p e r a t i o n a l  somewhat  115), h e r e  however,  from  as compared  £  f t . S.L.I.  ore recoveries.  the angle  5.72  5.71,  (#114  is clear,  above  & 30  slopes  11  high  as determined  tions  ment  No.  give It  side  side  even slope.  in the  No.8 o f T a b l e  section  along  the  5.  69. In conclusion, it can be said that the design of these proposed layouts permit adoption to the already existing development work, when flexib i l i t y is of great value for the f i r s t period of operation. 5-8  Change in the Angle of Sliding - Determined by Triaxial Compression Testing Equipment:Table 2, attached in Appendix III  - records some of the tests per-  formed, which clearly show the change in the angle of sliding and thereby a change in cave figures upon varying the test conditions.  These tests were  carried out with the ore samples from one particular place in the mine, but samples of ore collected from various locations in the mine representing different composition, can be tested to determine the difference in the flow properties for the purposes of quantitative design work. To illustrate the importance of Triaxial tests in designing the blast retreat distance, attention is drawn to Test Nos. 10, 11, 12, 13 and 14 of Table 2, Appendix Test No.  III. Moisture Content (M.C. %)  Angle of Sliding (Degrees)  10  NIL  65°  11  1.8%  64°  12  3.6%  69°  13  7.2%  61°  14  10.8%  51°  Figure 10 shows that the angle of sliding for the dry sample (Test No. 10) is 65°. A moisture content of 1.8% (Test No. 11) does alter the angle of sliding to 64°, but it is not very significant.  70.  ELLIPSOID OF MOTION  60'  ( 45 +<))-7-2) = 6 5 °  ANGLE OF SLIDING  II'  FIGURE 10 ANGLE OF SLIDING DETERMINED  WITH V A R Y I N G M O I S T U R E  BY T R I A X I A L  TEST  CONTENT  71 • Moisture content t h e mass and t e n d s the depth of  of  3.6.  to steepen  (Test No.  the a n g l e of  show a p r o g r e s s i v e  increase  of  t o 61° and 51° r e s p e c t i v e l y  soid of  motion. Material 14, f o r  an a r b i t r a r i l y of  description  c h o s e n No.  a solid  the f i n e  shearing  fraction.  hence  t o 69° -  hence  of  reduces  is  This  invariably  the  these  d i r e c t i o n , with  and f l a t t e n  Appendix It  is noted  in h i s  sieve  III) that  tests,  by  the f a c t  the angle  Jenike  the  of ellip-  in  tests  (38)  used  because the includes  the f l o w that  and 14)  13  was u s e d  s i z e s , which  governed  i s e x p l a i n e d by  Nos.  increase the depth of  ( T a b l e 3,  20 mesh m a t e r i a l  takes place across  in t h i s  "F"  -  c o n t a i n i n g a range o f  Nevertheless, study  the f l o w a b i l i t y  1.2% and 1 0 . 0 . ( T e s t  the above c o m p a r i s o n .  f i n e and c o a r s e p a r t i c l e s , of  sliding  in the f l o w a b i l i t y ,  sliding  bility  reduces  ellipsoid.  Whereas, moisture content  10 t h r o u g h  12)  flowaboth  properties  during  flow  the  fines.  tests  do  regard  i n d i c a t e the  importance of  t o G r a n d u c o r e and w a s t e .  extended  72. CHAPTER 6 CONCLUSIONS  While f u l l essential tainly Level  as f i n a l  scale testing  demonstration of  much p r e l i m i n a r y Caving  of  these  conclusions  1.  orebodies  is  at  reported treatment  results  s h o u l d be a v o i d e d  that  model  of  kind of  layouts  of  remain  tests,  cer-  Longitudinal  and t h e e f f e c t s  that  are d e s c r i b e d .  The  a few most  until  representative  extrapolation  further  analysis  Sub  of  d a t a on a l l  will following  configurasome  of  possible  may a t  completed at  the present  t h e model  permissible,  reduction of  r e c o v e r y and t o t a l  extraction  for  the conversion  and b u l k d e n s i t y  less  t h a n 70°, w i t h  production  drill  recoveries  a t 60 f t .  Higher  level  sub  bodies or  narrow  a footwal1  Jumbos sub  of  of  con-  results  slash,  so the  purposes.  based m a i n l y  is  on  required.  widths  which  stage  from  comparison  orebody  specifications  level  intervals  for  obtained  in the s t o p e  c o n d u c t e d on 20, 30, kO and 50 f t .  angles  is  figures  l e a s t be u s e d u s e f u l l y  a correction  the c o n s o l i d a t i o n  Tests  models,  geometrical  tests  However,  with  are  G r a n d u c M i n e s , and h e n c e ,  From t h e t h e o r y o f  that ore  3-  trial  these  would  available.  shows  2.  the  in t h e o r e t i c a l  a r e based on the  tions  figurations  conditions  the worth of  screening of  observations  t o be d e a l t w i t h  conclusions  natural  Method c o u l d be c o n d u c t e d on t h e m o d e l .  Qualitative have  under  is  at  footwal1  compatible  h a v e shown  improved  intervals.  60' w i t h  either  a n d medium d i p p i n g o r e b o d i e s  narrow with  and s t e e p  proper  F.W.  ore-  73. s l a s h show b e t t e r of  or  30'  suited  4.  It  to lower  there  sures  or  angle of blast  sub  level  s l i d i n g can,  same l e v e l  orebody  ore  with  footwall  steeper  recoveries  with  are  in terms o f waste development overall level  ore  ft.  30  s e e n f r o m t h e draw f i g u r e s c a n be e x t e n d e d loading  t o 60  intensity  level  50  per  level ft.  orebodies  the  drifts  on  orebodies  also,  longitudinal  the  revealed  angles,  but  a t 60  re-  ft.  sub  i s more e c o n o m i c a l  t o n o f o r e m i n e d and transverse  interval.  'A' and  in a p a r t i c u l a r  basis.  drifts  compared to  Further,  that  this  with  proper  This  is where  cost  also,  sub it  is  method  control there  standpoint  or t h e t r a n s v e r s e  situation.  in  optimum  acceptable ore  caving  from the development  s e l e c t i o n between c a v i n g method  level  dips  sub  for  in d r i f t s  much t o g a i n p r i m a r i l y proper  ft.  sub  twin  pres-  the change  in the d e s i g n o f  and a b o v e ) ,  footage  recovery at steeper  c a v i n g method a t  Study of  low f o o t w a l l  A layout with  longitudinal  equipment,  c a v i n g m e t h o d , has  low a t  (70°  a r e more  when t h e c o n f i n i n g  two e x t r a c t i o n  level  interval  ft.  30  testing  on t h e q u a n t i t a t i v e  sub  angles  are o b t a i n a b l e .  interval  triaxial  be u s e f u l  width, with  on a l o n g i t u d i n a l  that overall  the o r d e r o f  are v a r i e d .  therefore,  sub l e v e l  dipping orebodies  in the cave f i g u r e s  distance, etc.,  ft.  of  the a i d of  the m o i s t u r e contents  T e s t s on 50  level  interval  with  i s a change  retreat  coveries  compared to a lower  H o w e v e r , w i d e and f l a t  hS'.  has been o b s e r v e d ,  that  5.  recoveries  of is  by sub  the  74. CHAPTER 7 RECOMMENDATION  Recommendations f o r  7• 1  The inclusive, gravity fore,  literature  reveals  be c o n c l u d e d  The  this  It light  the is  relative  while  understanding is very  not  all-  in the f i e l d  limited.  It  in the  may,  of  there-  development  methods. 1, A p p e n d i x  II,  a r e not  conclusive,  a s s u m p t i o n s made i n t h e c a l c u l a t i o n s o f etc.  However,  importance of  appropriate  these  various  results  revealed  ore  rein  layouts.  from the work  such recommendations f o r  pro-  are useful  t o make r e c o m m e n d a t i o n s f o r o t h e r  o f w h a t has been  the f o l l o w i n g  s t a t e of  report,  f i e l d has q u i t e a c h a l l e n g e  in the T a b l e  several  in t h i s  the stope design  caving  results  Work:  contained  the p r e s e n t  and w a s t e d i l u t i o n s ,  determining  mind,  that  level  because of  coveries  in the  that  Future  review  f l o w as a p p l i e d t o  o f modern sub  marily  FOR FURTHER WORK AND D I S C U S S I O N .  so f a r .  further  investigations, With t h i s  and a d v a n c e d w o r k  in are  offered.  1.  Stoping  layouts  c a n be made o f their  ing  2.  and w a s t e .  Further  flowability  B a s e d on s u c h f l o w a b i l i t y  test  to check the p r e d i c t i o n s  and  also  of  the  data,  before  a mine  implement-  in the mine.  experimental of  b a s i s and u s e  and W a l k e r t h e o r i e s  in d e t e r m i n i n g the  c a n be c o n s t r u c t e d  the design  effect  J e n i k e and J o h n s o n  t e s t i n g equipment  broken ore model  s h o u l d be d e s i g n e d on a q u a n t i t a t i v e  blasting  w o r k c o u l d be d e v e l o p e d  in the model, or  to  introduce  some s c a l e d e f f e c t  the  thereof.  75.  T h i s would mean t h a t a n a l y s i s o f the model s c a l i n g laws has to be improved upon so t h a t model p r e d i c t i o n s are at  least variance with  reality.  It  i s seen t h a t mine model t e s t procedure adopted so f a r has  been  time consuming because o f the placement and r e c o v e r y o f s p e c i a l l y numbered rocks i n the model on t h r e e d i m e n s i o n a l g r i d . rocks were used as  indicators  o f the cave f i g u r e s .  i n o r d e r to draw s e c t i o n a l  There i s a scope f o r  c r e a s i n g the e f f i c i e n c y o f the t e s t i n g  Observations  in the f i e l d  o f any d e s i g n a d o p t e d .  (a.)  diagrams  improvement here i n i n -  procedure.  s h a l l have to be made to check the m e r i t  This, generally,  i s an e x t r e m e l y slow p r o -  cess s i n c e each problem u s u a l l y has f e a t u r e s p e c u l i a r t o However, techniques  The numbered  and i n s t r u m e n t a t i o n  To m o n i t o r the flow p a t t e r n  itself.  s h o u l d be d e v e l o p e d .  i n the stopes so as any c o r r e c -  t i v e measures be taken based on measurement  r a t h e r than on  hunch ( m o n i t o r i n g i n the mass-flow b i n s can be e a s i l y i n s t a l led and has been used w i t h some s u c c e s s ,  but f o r the p l u g -  flow type b i n s proper m o n i t o r i n g has y e t to be d e v e l o p e d ) . (b.)  To determine is  the e x t e n t o f c a v i n g i n the s t o p i n g area which  important from the o p e r a t i o n a l  as w e l l  as the s a f e t y  point  of v i e w ,  i.e.,  i n o r d e r to know i f t h e r e i s an adequate mat  o f waste  rock on the top o f a p a r t i c u l a r column o f o r e at  any  time and a l s o i n a s s e s s i n g a s i t u a t i o n beforehand when dangers from an a i r b l a s t  areimminent.  76. (c.)  For  f l o w p r o m o t i o n and f l o w c o r r e c t i o n  countering  an a r e a w h i c h  to the average  5.  Only v e r t i c a l However,  a few t e s t s  be t h e b e s t  6.  reacts exceptionally  conditions  blast/drill  for which  just  the caved waste  The model  tests  is  finer  than  c o u l d not g i v e exact but  intensity tional  of  do p r o v i d e  retreat  a very  t a k e n up  in t h e mine  tion operation. attention  control  7.2  here  7-21  in the  light  for  Drilling,  for  i n c l i n a t i o n of  area.  This  is  it.  of  The  lay-  i n some p a r t s ,  f a n s and  follow-up  d o e s n o t d e p e n d on t h e  the  to the should  test  operabe  area  regular  produc-  b l a s t i n g and l o a d i n g must be c a r r i e d  and, therefore,  & Practical  range  may  in the mine,  to the question  adjustments  a practical  more s l o w l y  c a n be k e p t by t h e p e r s o n  Operational Some o f  it  far,  relationship  the b l a s t e d ore  close  in a s e l e c t e d t e s t  designed.  i n t h e model s o  c a n be i m p r o v e d a c c o r d i n g  Therefore,  s h o u l d be s o c h o s e n t h a t  with  distance,  loading, e t c . ,  experience.  l a y o u t was  i n c l i n e d f a n s , as t h i s  answers  o u t s w h i c h h a v e been p r o p o s e d p r o v i d e For e x a m p l e , b l a s t  unfavourably  in case the f r a g m e n t a t i o n  such t h a t  optimum l a y o u t ,  the  f a n s have been t e s t e d  s h o u l d be done w i t h  proposal  i n t h e s t o p e on e n -  out  t h a n n o r m a l s o a good  in charge of  this  operation.  Detail:  the parameters of  sub  level  o f o p e r a t i n g and p r a c t i c a l  c a v i n g method a r e  discussed  detail.  Fragmentat i o n : It  parameters.  is  known t h a t  fragmentation of  How much f i n e o r e  o r e and w a s t e  is  t h e key t o  s h o u l d be b r o k e n , d e p e n d s on t h e  other  appearance  77. of waste  from the cave.  As t h e o r e  be d e s i r a b l e  to accept  a rather  not  seriously  at  look  too  which w i l l  7.22  with  to  irregular  the  coarse  for  to  break  it  fragmentation. costs,  the e n t i r e  but  would,  of  course,  However, one  permit  a  should  fragmentation  operation.  Interval:  One c a n f i n d terval  costly  the b l a s t i n g  be most p r o f i t a b l e  Sub L e v e l  is  normal  f r o m t h e model  conditions.  shape o f  tests,  the best  possible  B u t s o m e t i m e s much a t t e n t i o n  the orebody  as w e l l  as  to  its  sub has  dip  level t o be  and p i t c h  ingiven  on  making such a d e c i s i o n . Another  factor  t a t i o n of  ore.  increases  the d r i l l i n g  t o be u s e d cal  Higher  to achieve  Fan  regard  level  costs  is  intervals  rapidly,  the ease of require  especially  acceptable fragmentation. limit  for  each type of  b l a s t i n g and  longer  if  closer  Thus,  ore,  drill  holes  hole  there  fragmenwhich  placing  has  i s an e c o n o m i -  w h i c h must n o t  be  exceeded.  1nclinat ion:  Optimum f a n recovery,  this  sub  and a l s o p r a c t i c a l  7.23  in  longhole  inclination  drilling  is  determined which  efficiency,  safety  is compatible with  and o t h e r  operational  ore  pro-  blems . Theoretically, compared w i t h  90°  the  inclined  first  layouts.  used  in the  fans  inclined  forward  10°  rings rings.  -  have  from the d r i l l i n g  point  of  is  there  this  recovery which inclination  seem t o be o t h e r  is  better  should  be  reasons  for  hole  20°.  rings  the c o l l a r i n g  Therefore,  However,  Vertical  as  g i v e an o v e r a l l  certain  view;  done f u r t h e r  potential  whereas,  operational  inclined  holes  away f r o m t h e o p e r a t o r  disadvantages  have and,  the  advantages  therefore,  78.  w a t e r and  sludge  do  not  fall  d i r e c t l y onto the machine or  is a l s o e a s i e r t o charge the d r i l l  fan c l o s e s t  inclined  be a v a i l a b l e  forward  as more room w i l l  t o the f r o n t  T h i s , a l s o , c r e a t e s a s t r o n g e r brow w h i c h  have  grounds.  With drill  t h e H.W.  footages  r e t r e a t method  are 20  -  25%  angles w i t h orebody dips considered been  Blast  Retreat  the  important  f r o m F.W.  h o l e s compared  t o H.W.),  to  This point should  to  vertical be s t r o n g l y  r e t r e a t method  has  Distance:  Blast  retreat distance or for vertical  used, the b l a s t depth  the f o l l o w - u p system be  7-25  adjusted  will  be  the b l a s t depth hole fans.  smaller.  (Section 7-1)  determined  If inclined  H o w e v e r , as  are obtained,  from the  model  hole fans are  s o o n as  the b l a s t  results  retreat  to from  distance  i f necessary.  Time F a c t o r : It  i s known t h a t t i m e  granular materials. time,  inclined  i n t h e c a s e o f G r a n d u c M i n e s w h e r e t h e H.W.  tests are only v a l i d  should  retreating  range o f 6 5 ° .  in the  i s most  are  planned.  7.2k  be  less with  (i.e.,  It  i f the holes  b e t w e e n t h e b a c k and  muck p i l e . i n bad  the o p e r a t o r .  the s o l i d s  s o l i d a t e d , which the cohesion  has  certain  I f the b l a s t e d column o f o r e  remain under a c t i o n o f s t a t i c reduces  their  flowability.  f o r c e s i n the b l a s t e d ore  hangups o r doming can loaded  too  long.  effect  in  fu11.  e f f e c t s on  occur.  Field  still  Therefore,  is left  pressure  unloaded  and,  strengthen  is present,  i t , at which  should  be n e c e s s a r y  f o r some  t h e r e f o r e , con-  Further, i f water  the b l a s t s  investigations will  the flow p r o p e r t i e s of  not  be  to study  left this  serious un-  79. 7.26  The f o l l o w i n g a d d i t i o n a l practical  A.  It  den t o f i v e  feet  how " t i g h t "  the p o s i t i o n  be n e c e s s a r y  extraction  is  drift  in other words, sub  tween t h e H.W. this  corner  the c o n t a c t It  ly,  perhaps  c o u l d be d r i l l e d angle  to the  7.27  13,  ensure  training, quality of the  stope.  -  5 ft.  burdens  e a s e r h o l e s as shown  there  of  a successive narrowing of  break.  caving  and t h e f a n s so t i g h t  layout  tends  (Figure  12),  t o be t i g h t .  because  it  it  "tight"  12. ore  corners,  In a n o r m a l  the c o n t a c t On t h e F.W.  i s normal  would  in Figure  a s t o p e f r o m an to get  bur-  d e p e n d i n g on  are t r i e d ,  is a tendency  less desirably  re-orientating  the b r e a k i n g of  from the p o i n t of  in a v e e - s h a p e d normal  to d r i l l  be-  side,  along  the fans  the  ring.  view of  (in  but  as  Alternative-  recovery,  to the f o o t w a l 1 ,  plan)  the  fans  a t an o b t u s e  hangingwall.  Loading:  f r o m t h e F.W. important  proper  bigger  from d r i l l i n g a l l  to ease s l i g h t l y  Loading/mucking  extremely  If  t o 4,1/2  reduce the fan  thus e n s u r i n g a b r e a k .  Intensity of  ing e i t h e r  is.  may be p o s s i b l e t o c o n s i d e r  in Figure  but  toe burdens  that  level  i s not  a t some m i n e s , t o  to d r i l l  arises  longitudinal  shown  and t h e  One p r o b l e m t h a t  or  to  trial:  has been f o u n d n e c e s s a r y ,  probably B.  p o i n t s may be c o n s i d e r e d w i t h a v i e w  intensity or  side of  in the case o f  f u n c t i o n i n g at  closer  H.W.  supervision  much p r o d u c e d  i s e x p r e s s e d as a p r o p e r the e x t r a c t i o n  longitudinal  the o p e r a t i n g  level,  and i n t r o d u c t i o n  rather  sub  of  t h a n on t h e t o t a l  r a t i o of  drift.  level  This  tons of  is  caving method.  i t would r e q u i r e a bonus  load-  operator  s y s t e m b a s e d on rock  To  removed  the  from  THE HOLES FOR THE EASER RING (BROKEN LINES) SHOULD BE DRILLED FROM THE SAME SET-UP AND ANGLED FORWARD SO THAT THE COLLARS ARE NOT DAMAGED BY THE PREVIOUS BLAST.  ;  VERTICAL  FIGURE  SECTION  ^-  -  - -  ^  t  a , „  ALONG THE LONGITUDINAL  12. LONGITUDINAL  AXIS OF EXTRACTION DRIFT  SUB L E V E L  SECTION  CAVING - P O S S I B L E POSITIONING  OF  I-I  EASER  HOLES.  81.  PLAN  FIGURE 13 . LONGITUDINAL HOLE FANS.  SUB L E V E L CAVING - V E E  SHAPED LONG  82. .3  Comments on t h e Q u a n t i t a t i v e Quantitative  tope 1.  layouts  for  design of  the f o l l o w i n g  The s l o p e s o f ing  bin  is e a s i e r  the hopper  portion of  stope d e s i g n ,  of  it  flow  may be p o s s i b l e  side only  by s l a s h i n g  than the d i p of overall,  level  for  as  2.  from the  or  1  t h e dead  bin. for  loads or  i n g may n o t  tests.  flow  Whereas,  the s l a s h  steeper  rock  caving  is  F.W.  steeper  is economical  s l o p e s o n t h e H.W.  the p r o h i b i t i v e  level  properties  design of  of  only  bulk s o l i d  are determined before  in  length  side  of  b e l o w s p e c i a l l y on a s u b  in the bins  is either  caused  hand.  o f o r e and w a s t e  bins, is  generally  samples of  in  flow  a stope,  rock have d i f f e r e n t  o r e and w a s t e  the  blast-  stope.  the storage  c o n s i d e r e d whose  In t h e c a s e o f  w h e r e b r o k e n o r e and c a v e d w a s t e intermixing of  the c o n s o l i d a t i n g e f f e c t  the  r e p r o d u c i b l e on t h e t e s t e d s a m p l e meant  the q u a n t i t a t i v e  continuous  level  c a n be s i m u l a t e d on t h e t e s t e d  In  one t y p e o f  sub  and w a s t e  due t o t h e f a l l i n g m a t e r i a l on t h e t o p o f  be c o m p l e t e l y  to d e t e r m i n e the  the ore  Now,  higher.  These c o n s o l i d a t i o n s flowability  of  accord-  the d e s i g n e d s l o p e on the  C o n s o l i d a t i o n of m a t e r i a l which occurs by  3.  60  of  the Tr.  l o n g as  the maintenance of  of  is charged w i t h .  (when t h e d e s i g n e d s l o p e c a l l e d f o r  t o be d r i l l e d  interval  it  properties  may n o t be p o s s i b l e m a i n l y b e c a u s e o f longholes  than the d e s i g n  t h e b i n c a n be d e s i g n e d  to achieve  the orebody)  whereas  Stopes:  to a c h i e v e  material  c a n be d e t e r m i n e d and s i d e s l o p e s stopes  the  reasons:  to the f l o w p r o p e r t i e s  the case of  Design of  and  flow  properties  especially flow  properties,  in the e l l i p s o i d of  motion  83. may p r o d u c e modern sub ful of out  only  products level  of  variable  flowability.  The d e s i g n  s t o p i n g m e t h o d s w o u l d be c o n s i d e r e d f u l l y  when p r o b l e m s a r i s i n g  form a s p e c i a l l y changed  designed for  dilutions. brought  the e x t r a c t i o n  There  is a vast  in the d e s i g n of  ance can e a s i l y crease  average c o n d i t i o n s  Granduc Mines a l o n e t h i s mately  $29-0  expected  sub  ore  million.  planned ore  level  say f o r  example, even  sub  36.0  be  import-  a 5%  c o u l d be a c h i e v e d ,  approximately level  its  if  lay-  and w a s t e  improvement w h i c h c o u l d  c o u l d mean an a d d i t i o n a l of  in a  effectively  recoveries  c a v i n g m e t h o d s and  recoveries  (5%  t o be m i n e d w i t h  c o u l d be d e a l t w i t h  scope f o r  be r e a l i z e d -  in the o v e r a l l  of  success-  situation  f l o w c a u s e d by f r a g m e n t a t i o n o r m o i s t u r e c o n t e n t , e t c . ,  so as t o e n s u r e  of  in-  then  income o f  for approxi-  m i l l i o n tons of  c a v i n g methods 3 (> s a y  $16.0  ore  ore).  84 LIST  OF'REFERENCES  1.  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ASCE, Paper No. 2939, PP. 792-811.  30.  Johanson, J.R. - "The Placement of Inserts to Correct Flow in Bins", Powder Technol., 1 (1967/68) PP. 328-333-  31.  Handley, M.F., and Perry, M.G. - "Stresses in Granular Materials Flowing in Converging Hopper Sections", Powder Technol., 1 (1967/68) PP. 245-251-  32.  Bepco Canada Ltd. - "Monitoring Levels of Granular Solids", Canadian Chemical Processing, Dec. 1958, PP. 95~96.  33-  Beck, M.S., and Wainwright, N. - "Current Industrial Methods of Solids Flow Detection and Measurement", Powder Technol., 2, (1967/68) PP. 189-197-  34.  Nicholls, H. - "A Case Study of the Validity of Scaling Laws for Explosion-Generated Motion", U.S. Bureau of Mines - Report of Investigation 6472, 1963, PP. 14.  35-  Duncan, W.J. - "Physical Similarity and Dimensional Analysis, an Elementary Treatise", (1953)-  36.  Jenike, A.W., Elsey, P.J., and Wooley, R.H. - "Flow of Bulk Solids. Progress Report:, Bulletin 96. 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APPENDIX  The  pertinent  the s t o p e ,  variables  a r e as  considered  I  in the a n a l y s i s  of  the g r a v i t y  NOTATION  1.  Draw  2.  A significant  3.  Any p e r t i n e n t  h.  Area of  5.  Hydraulic  L3  distance  1  L  distance  Ai  L  the opening  (free  diameter of area -  7.  Average  s i z e of  the  8.  Head o f  p a c k i n g above  9.  True d e n s i t y  of  solids  10.  Bulk density  of  packing  11.  Volume o f  12.  Digging  13.  Velocity  of  14.  Angle of  internal  15.  Angle of  side  V = f It  is  (1, A i ,  t o be n o t e d  made b e f o r e  opening  the m a t e r i a l  (dead  load)  ML  w  particle  the  discharge  opening  _ 2  L  H  L  ML"3 ML"3 L  scoop  v  friction  slopes  of  inclination  bottom)  6  DL, W, d ,  that  the  proceeding with  LT-'  0  (angle  of  H,  f>s,  following the  the stope /°b, V  is a function c >  d , d  v,  analysis:  of:  0, 6)  s i m p l i f y i n g assumptions  3  L  dd  from opening  T  d  A A  draw c o m i n g o u t A,  %  container  depth of  So t h e v o l u m e o f  A  Perimeter  of  the hopper  flow)  the  S p e c i f i c weight  the  DIMENSION  V  Volume  6.  of  in  follows:  VARIABLE:  = 4 x free  flow  -  have  (l) been  "  2  91 •  1.  No e f f e c t  2.  No o t h e r  o f m o i s t u r e has been forces  t h a n o f t h e mass o f b r o k e n  sides of the stopes  h a s been  P'o o f t h e o r e a n d w a s t e  3.  considered. r o c k a b o v e o r on t h e  considered.  i s a s s u m e d t o b e t h e same i n t h e a r e a o f  draw. Consolidating pressures offered  k.  by t h e b l a s t i n g a c t i o n h a s n o t b e e n  considered. Generally  5.  equal  l o a d i n g o f t h e m a t e r i a l h a s b e e n done f r o m  end o f t h e o p e n i n g f o r T r a n s v e r s e Sub L e v e l  From t h e t h e o r y o f m o d e l s , TTi  = F  2  .TT ) S  3  Where a l l t h e P i (TT)  which  equation  T7 , TTi,  (TT ,  Since equation  i f the general  Caving  Method.  f o r the prototype -  either  is:  (2A)  terms a r e d i m e n s i o n l e s s and i n d e p e n d e n t .  (2A) i s e n t i r e l y  general,  it applies  i s a f u n c t i o n o f t h e same v a r i a b l e s .  Hence,  t o any o t h e r it applies  system  to a s p e c i f i c  system c a l l e d the model.  "^Im An e q u a t i o n equation Therefore:  -  F  ( T T  TTSm.  ^ m  f o r p r e d i c t i n g TTi  "  from T T ]  m  ^  J "  (2B)  may be f o u n d d i r e c t l y  by d i v i d i n g  ( 2 A ) by e q u a t i o n ( 2 B ) . TT,  =  TTi Now,  2m'  i f t h e model  (TT  F  (n  2  m  TT  TT3,  2 >  ,  3  TT  S  2 m  m  TT )  M  S  T T - J , TTZi  i s d e s i g n e d and o p e r a t e d  TT n  F  =  TT  "  ^3  =  TT  TT  S m  -  (2C)  )  so t h a t  2  S  (2D)  92. It f o l l o w s  F  that:  TT3,  (TT , 2  Tlli  TT )  The n a t u r e o f t h e f u n c t i o n equation  TTj  =  (2C) a n d ( 2 E ) , i t TT] ;  To a p p l y  (TT  2 m  »  TT  TT  3 m  S m  - (2E)  )  f o r t h e model a n d p r o t o t y p e  because  is apparent  that:  the p r e d i c t i o n  1 5  equation.  e q u a t i o n (1):  M,  F (1,  =  this  m  rewriting V  is identical  F  (2A) i s g e n e r a l .  From e q u a t i o n  Now,  =  5  A,  W, d, H  DL,  dimensional analysis  ,/=s,  /»b, V , c  and t h e o r y o f m o d e l s ,  d , v,  0, 6) -  d  Equation  (l)  (1) may be  written as: Vd  l dd  c  AC * D c5  c  12  The c o r r e s p o n d i n g  (L3)cl  A i 3  2  v  1  h  cl3  0cl4  L  (ML"3)clO From t h e a b o v e ,  cl5  e  L  +  Cg  o  -  M:  C6  (C)  -  L:  3C] + C2 +  Since values  three  T:  - 2C6  equations  - (A)  Lcl2  L C 7 L C 8 (ML"3)c9  (LT~1)cl3  +  C]0 =  (-)clA  (-)cl5  = 0  0  C3 + 2C/, +  Ci 3  =  +  C5 - 2Cg +  C7 + C8  C12 ~ C13  = 0  0  are available for solving  must b e a s s i g n e d  c  is:  - 3Cg - 3C]0 + 3 C i ] -  v 'l  e q u a t i o n s may be w r i t t e n a s :  (B)  (D)  s  C 5 (ML"2 T-2)  (L3)cll  the a u x i l i a r y  HC8 ^ c 9 / ^ b c l O  dc7  c 6  =  dimensional equation  C 2 C 3 (L2)c4  L  W  to ten o f t h e unknowns,  thirteen  unknowns,  arbitrary  many c o m b i n a t i o n s a r e  possible, C11,  C12»  of  t h e s e one  t]k>  involving:  C-|5,  The d e t e r m i n a n t  of  has been  C],  Cz,,  C3,  C5,  Cfc,  C7,  C8,  C]Q,  selected.  the c o e f f i c i e n t s  of  the  r e m a i n i n g terms  C2,  C9 and  C]3  I s:  0  1  0 this  is not  equal is  to z e r o ,  the  resulting  equations  valid.  are assigned a r b i t r a r i l y Cl  1  3  0  C  0  0 - 1  and t h e s e l e c t i o n Values  *  1  -3  1  Since  0  as  follows:  0 5  0  C6  0  7  0  C8  0  10  0  1  0  C12  0  c  C  c  Cl  Substitute  these values  in equations  (B),  Cg  3 + C From e q u a t i o n s  C  2  3Cg - C13  1 3  3a, C  -  2  3b =  "3  and  (C),  (D)  = 0  •3a  0  •3b  = 0  •3c  =•  3c:  and f r o m a b o v e :  C]  = 1  are  independent  3k.  From t h i s  and e q u a t i o n  TT,  =  (A)  -  dropping  I  v_  13 From t h e P i mined.  theorem,  Another  arbitrary  Substitute  i s seen t h a t  a total  of  10 P i  t e r m s must be  t e r m may be f o u n d by s e l e c t i n g a d i f f e r e n t  values  for  the s e l e c t e d e x p o n e n t s ;  Cj  =  0  C  -  1  Cz,  =  0  c  5  =  0  c  6  =  0  c  7  =  0  C8  =  0  C  =  0  Cl i  =  o  c  =  o  3  1 0  1 2  above  C  in e q u a t i o n s  (B),  9  C  From E q u a t i o n s  = +  2  -C  1  1 " 3Cg  3  -C|  3  (C),  0  for  example:  (D)  -ka  =  0  -kb  =  0  -kc  ha, kb, kc: C  From t h i s  it  2  =  -1;  and e q u a t i o n TTo  =  (A)  Ai  and fpom a b o v e : dropping  Co,  C^ or:  ||  =  1  deter-  combination  of  95. Another  Pi  t e r m may be f o u n d by  equal led to  letting  Cj, =  I with other  selected  exponents  zero:  TT3  A_  =  III  12 Similarly, C8,  Cg,  s e v e n more  C11,  ponents  equal  C]2  independent  and C13  to zero,  Pi terms a r e developed  in t u r n ,  equal  unity,  with  by  letting  the other  selected  thus: IV  TT  n  =  5  6  w.l  -  1  =  1  TT-,  =  H_  VI  -  VII  1 TT  8  TTg  =  A  -  VIII  =  V  -  IX  c  13 TT  And a l s o f o r  =  10  £d  = 0  n  TT12  6  A general  s o l u t i o n may,  V_  ( Ai , k_, D h , w j _ , 1 l 1 />s v  l3  F  X  the d i m e n s i o n l e s s v a r i a b l e s  n  =  -  1  2  -  XI  -  XII  therefore, d, 2  1  0,  be w r i t t e n  6:  as:  A,  ^c,  £d,  1 /°s  l3  1  H_,  0,  6)  C5,  -  (5)  C5, ex-  A P P E N D I X  TABLES  1 and IA -  II  RESULTS.  T A B L E  1  (LONGITUDINAL  SUB  LEVEL  CAVING)  LOADING PATTERN  F.W.  H.W.  1  2  3  4  5  1 19 20' 60° 60' 2 26 20' 60° 60'  6  7  8  9  10  7'  1.46 1.50  G  7'  1.68 1.60 1.35  D  11 0-125 0-85  SC = SC =  12 1: 1 0: 1  13  14  15  16  17  18  83 59.5  19  8736 9163  125 125 132 132  134 85.0  80°  NO  F.W.SLASH F.W.SLASH  85-200 SC = 1 : 1 3 22 20' 65° 60' 4 24 20' 65° 60'  6'  1.68 1.60 1.35  D  0-100  SC =  1 :1  7128  100 100  130 71.0  NO  6'  1.68 1.60 1.35  D  0-120  SC =  0 :1  7980  115 115  146 86.6  90°  F.W.SLASH  80°  F.W.SLASH  F.W.SLASH  120-200 SC = 1::1 5 27 20' 65° 60'  8'  1.68 1.60 1.35  6 27 20' 65° 60' 7 27 20' 65° 45' 8 27 20' 65° 45'  6' 8'  1.68 1.60 1.35 1.68 1.60 1.35  A  6'  1.68 1.60 1.35  A  8'  1.68 1.60 1.35 1.68 1.60 1.35 1.68 1.60 1.35  9 27 20' 65° 30' 10 27 20' 65° 30' 11 28 20' 65° 60'  6' 8'  A  II  II  9944  142 142  A  II  II  7458  106 106  130 86.3 33-9 127 82.6 35-4  II  n  7216  II  II  5616  103 103 80 80  129 80.7 37.4 118 78.4 33-9  A  II  II  4536  65  A  II  n  3726  52  A  0-90  SC =  0::1  10048  65 52  123 69.O 43.9 120 69.4 35.5  144 144  144 90.8 37-1  • 1  ..  i, 85°  F.W.SLASH  90-200 SC = 1::1 V*  VOLUME  OF  HEAPED BUCKET  N * * - DRAW F I G U R E S SC - S C O O P S DRAWN.  OF SCOOP  P L O T T E D AND COLUMNS  -  112 16,  CU.FT. 17,  18 C A L C U L A T E D  FOR N O .  OF  SCOOPS  DRAWN  1  N  1  U3  1  2  3  12  28  13 14  4  5  6  7  20'  65° 60'  1.68  28  20'  65° 60'  7' 6'  28  20'  65°  8'  45'  8  9  11  10  90-200 S C =  1.68  1.60 1 -35 A 1.60 1.35 A  1.68  1.60 1.35  0-90  A  II  SC  90-200 15  28  20'  16  28  20'  65° 45' 65° 45'  17  28  20'  65°  30'  18  28  20'  65°  19  37  20  126  152  90.5 4 0 . 6  7536  106  106 1  138  84.6  38.8  1.  0::1  7320  105  105  137  85.0 37.8  .1  SC =  85°  F.W.SLASH  1::1  A  II  11  5430  78  78  114  80.5 39.4  ..  A  II  n  4536  65  65  124  66.3 4 6 . 5  ,,  A  II  II  3402  49  131  73-0 44.6  ,.  F  II  II  II  n  II  II  II  30'  1.68  20'  65° 60'  10'  1.56  1.60 1-35 1.56  37  20'  65° 60'  8'  1.56  1.56  F  21  37  20'  65° 60'  8'  1.56  1.56  F  22  37 20' 65° 60' 37 20' 65° 60'  7' 6'  1.56  1.56  F  1.56  1.56  F  37 20' 65° 60' 37 20' 65° 45' 37 20' 65° 45'  5'  1.56  1.56  8'  1.56  1.56  F  6'  1.56  1.56  F  8'  1.56  1.56  F  6'  1.56  1.56  F  1.56  1.56  F  1.56  1.56  E E  A  F  23  37 20' 65° 30' 37 20' 65° 30' 37 20' 65° 30*  30  35  20'  65° 60'  5' 8'  31  35  20'  65° 60'  6'  1.56  1.56  32  35  6'  1.56  1.56  33  35  65° 45' 65° 30'  8'  1.56  1.56  E  9 30' 60° 60'  8'  1.80  1.80  B  34  126  1::1  .,  1.68  20'  8732  II  86.3 38.2  8' 6'  20'  19  18  140  1.60 1.35 1.60 1.35  28  17  92  1.68  27  16  92  6'  26  15  6405  1.60 1.35  25  14  II  1.68  24  13  II  7'  23  =  12  E  54  12560  173  191  120  81.9  10048  140  154  121  86.1  28.3 28.4  10048  140  167  134  87.1  34.2  II  8792 121  135  121  82.3 31.8  II  II  7536 103  115  125  II  II  6280  86  96  124  79.7 35-9 74.0 4 0 . 5  II  II  7520  124  83-5 3 2 . 5  n  II  5395  74  82  81.1 29.2  II  n  5024  70  77  115 122  63.6 43.2  II  II  3360  46  51  118  66.7 43.2  ,,  11  II  2800  39  43  120  59.3 50.5  .1  II  II  140  154  112  74.9 33.0  II  II  7536  104  115  113  71.2  II  II  5652  72  79  113  II  II  5024  70  77  15520 199  219  0-230 S C = 1::3  10048  104  115  37.1  80°  F.W.SLASH  .1  1.  .. '  ,.  80°  F.W.SLASH  1:20  SCALE  71.3 37.1  11  11  107  54.0 49.1  11  11  13  82.5 1 8 . 0  NO  F.W.  TEST  SLASH  1  2  3  4  5  58  36 3 0 '  65°  30'  6  7  8  5'  1.56  1.56  9  11  10 F  0-9-  SC =  12  0::1  9 0 - 2 7 5 SC = 59  25 30'  75°  60'  10'  1.68  1,60  1.35  A  0-110 SC =  4430  13  14  15 68  6.2  16  17  123 55.4  19  18  5 4 . 7 80° P . W . SLASH  1::1 0::1  1691 2 242  242  132 83.5  NO F . W . SLASH  1 10-130 SC = 2:: 1 130-260 SC = 1 : : 1 75°  60'  8'  1.68  1.60  1.35  A  II  II  13529  193  193  121  87.4  27.9  75°  45'  8'  1.68  1.60  1.35  A  II  II  10150  145  145  126  80.3  36.3  25 3 0 '  75°  45'  6'  1.68  1.60  1.35  A  II  II  7340  102  125  67.0  46.4  63  25 3 0 '  75°  30'  8'  1.68  1.60  1.35  A  II  II  6757  97  64  25 3 0 '  75°  30'  6'  1.68  1.60  1.35  A  it  II  4650  65  65  14 4 0 '  55°  60'  6  1.80  1.80  B  66  14 4 0 '  55°  60'  5'  1.80 1.80  B  II  n  67  14 4 0 '  55°  45'  6'  1.80  1.80  B  II  II  68  14 40'  55°  45'  5'  1.80 1.80  B  II  II  69  14 4 0 '  55°  30'  6'  1.80  1.80  B  II  II  70  14 40'  55°  30'  5'  1.80  1.80  B  II  II  71  13 4 0 '  65°  60'  1.80 1.80  B  72  13  40'  65°  45'  5" 8'  1.80 1.80  B  73  13 4 0 '  65°  45'  7'  1.80 1.80  B  74  13 4 0 '  65°  45'  5'  1.80 1.80  B  75  13  40'  65°  30'  7'  1.80 1.80  B  76  13  40'  65°  30'  5'  1.80 1.80  77  31  40'  65°  60'  10'  1.56  60  25 30'  61  25  62  30'  1  1.56  0-260 SC =  0-210 SC =  1::3  II  II  n  II  II  II  n  II  B  II  II  F  0-180  SC =  0:: 1  72  125  .. .,  52.2 5 8 . 2  1,  28,4  .1  261  102 73.0  13550 218  218  127 6 8 . 7 4 6 . 2  12198  196  196  102 75.8  10165  I63  I63  126 7 5 - 7 39.8  ..  8130 131  108  81.4  24.9  ,.  109  131 109  127  81.4  35-6  .1  12450 200  200  118 74.8  36.7  239  239  105 8 2 . 5  21.7  11  13027 209  209  121  8 4 . 7 29.5  1,  77.6 32.1  1,  14888  25-5  .1  ,,  131  131  115  8547  137  137  117 70.0  .,  6105  98  98  1  ,i  392  10 6 4 . 9  119 90.0  25.4  1.  ..  9305  25450 356  180-300 SC = 1 : : 1  123 52.4 57.6  97  ..  16260 261  6775  1::3  115  ..  80°  F.W.SLASH  1  2  3 k  35 9 30' 60° 36 9 30' 60° 9 30' 60° 37 9 30' 60° 38 9 30' 60° 39 4o 7 30' 6 5 ° k] 10 30' 6 5 ° kl 21 30' 65° k3 21 30' 65° kk 21 30' 65° 45 21 30' 6 5 ° 46 21 30' 6 5 ° kl 36 30' 65° 48 k3  50 51 52 53 5k  55 56 57  36 36 36 36 36 36 36 36 36 36  30' 30' 30' 30' 30' 30' 30' 30'  5  6  7  8  60' 60' 30'  7' 6' 8' 7" 6' 8' 8' 8' 8' 6' 8' 6' 1 0'  1.80 1.80 1.80 1.80 1.80 1.80 1.80 1.68 1.68 1.68 1.68 1.86 1.56  1.80  B  1.80  B  II  II  1.80  B  II  II  1.80 1.80 1.80 1.80 1.60 1.35 1.60 1.35 1.60 1.35 1.60 1.35 1.60 1.35 1.56  B  n  II  II  II  9' 8' 8' 7' 6' 8' 6' 5' 8' 6'  1.56 1.56 1.56 1.56 1.56 1.56 1.56 1.56 1.56 1.56  30'  30' 60'  60' 60' 45' k5'  30' 30' 60'  6 5 ° 60'  65° 65° 65° 65° 65° 65° 65° 30' 65° 30' 65°  60'  60' 60' 60' H5' k5'  45' 30' 30'  1.56 1.56 1.56 1.56 1.56 1.56 1.56 1.56 1.56 1.56  9  10  B B B A  11  12  0-230 SC = 1 : :3  0-260 SC = 1:: 1 0-260 SC = 3:: 1 0-210 SC = 1::1  A  II  II  A  II  II  A  II  II  n  n  A F  0-90 SC = 0::1 90-275 SC = 1::1  F  II  n  F  II  II  F  II  II  F  II  II  F  II  II  ii  II  F  II  II  F  II  II  F  II  II  ti  II  F  F  13  14  13580 152 11640 112 7440 114 6510 101  5580  86  14880 239 14880 239  14720 10792 8145 6832 5045 19280  210 154 116 98 71 270  17352 15424 15424 13496 11568 11252 8250 6875  16  167 123 126 111  102 77.6 25.0 110 74.8 32.0 117 68.0 41.8 109 59.0 45.6  95 261 261  108 71.0 25.0  210 154 128  17  18  113 81.0 27.9 1 10 54.7 32.3 118 80.1 32.1 117 84.7 27.7 134 84.1 37.4 132 73.4 44.2 123 86.8 25-7  242  266  215  237  215  258  188 161 157 115  207  122 88.1 124 89.3 138 90.4 122 85.9  95  74  19 NO F . W . S L A S H  177 173  11  n  in  11  11  11  11  11  11  11  11  n  11  n  n  11  11  n  11  F.W.SLASH  80°  27.5  11  11  28.0  11  11  32.8  11  11  29.5  11  11  11  11  n  11  11  11  11  11  11  11  n  11  126 81.0 35.4  120 73.5 127 123 77.5 105 121 71.7 115 122 57.7 81 124 59.9  11  NO F . W . S L A S H  132 83.O 37.0  98 78 296  7499 104 5310  15  39-4 36.8 40.6 53-3 51.9  o o  1  2  78  31 40' 65° 60'  3  4  5  6  7  8  8' 1.56 1.56  9  10  11  12  F  0-180 SC = 0::1  13  14  15  16  17  13  18  20720  296  314  115 90.5 21.3  20720  296  345  134 91 .2 32.1  233 1 5270 212  257 236  117 85-7 27.3 120 76.4 36.6  14976  210  230  118 84.6 31.0  11232  156  172  111 65-8 35.6  6100  85  94  99 45-5 53-9  80° F . W . S L A S H  180-300 SC = 1::1  8' 1.56 1.56  F  80  31 40" 65° 60' 31 40' 65° 60'  7' 1.56 1.56  F  81  31 40' 65° 60'  6' 1.56 1.56  F  .,  82  31 40' 65° 45'  8' 1.56 1.56  F  ,,  83  31 40' 65° 45'  6' 1.56 1.56  F  84  31 40' 65° 30'  5' 1.56 1.56  F  85  33 50' 55° 60'  8' 1.46 1.50  G  SEE TABLE 6  18624  246  270  110 59-8 48.1  DRIFT  'A'  86  33 50' 55° 60'  6' 1.46 1.50  G  SEE TABLE 6  13968  184  203  111 62.0 50.6  DRIFT  'A'  87 88  33 50' 55° 60'  6' 1.46 1.50  G  SEE TABLE 6  88  97  115 82.0 42.0  DRIFT  'B'  33 50' 55° 60'  4' 1.46 1.50  G  SEE TABLE 6  89  32 50' 70° 60'  8' 1.56 1.60  F  90  32 50' 70° 60'  6' 1.56 1.60  31  32 50' 70° 60'  92  32 50' 70° 60'  6' 1.56 1.60 4' 1.56 1.60  79  II  11  „  n  17815  673?  11  11  n  11  11  11  11  11  11  11  59  65  110 61 .0 44.1  DRIFT  'B'  SEE TABLE 7  4488 14120  201  221  110 77-6 23.4  DRIFT  'A'  F  SEE TABLE 7  10590  151 1  166  1 11 67.1 42.0  DRIFT  'A'  F  SEE TABLE 7  106  DRIFT  'B'  SEE TABLE 7  117 78  110 79-8 27.4  F  9300 6200  110 62.5 43.0  DRIFT  'B'  71  DRIFT 'A^'B'  94  33 50' 55° 60' 8'-4' 1.46 1.50 33 50' 55° 60' 8'_6' 1.46 1.50  23112 25356  110 60.1 112 65-8  95  33 50' 55° 60' 6'-6' 1.46 1.50  20700  112 68.4  96  33 50' 55° 60' 6'_4' 1.46 1.50  18456  111 61.7  93  o  1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  DRIFT 'A'-'B  97  32 50' 70° 60' 8'-4' 1.56 1.60  20320  110  73.0  98  32 50' 70° 60' 8'-6' 1.56 1.60  23420  110  78.4  99  32 50' 70° 60' 6'-6' 1.56 1.60  19890  1 10 73-0  100  32 50' 70° 60" 6'-4' 1.56 1.60  16790  110  65-3  18  19  TABLE  IA  (TRANSVERSE SUB LEVEL CAVING)  LOADING PATTERN W.::F.W.  101 102 103  104 105 106 107 108  4 4 4 4 4 6 6 6 6  79°  30'  10' 1.80  1.80  B  79° 79°  30'  1.80  B  79°  30'  8' 1.80 7' 1.80 6' 1.80  79° 74°  30'  74°  30'  74°  30'  30'  30'  109 74° 30' 1 10 20 79° 30' 11 1 20 79° 30' 112  20  °  30'  113  20 79°  30' 30'  7 9  1 1 84° 115 11 84° 114  V*  -  30'  0-200 SC = 1::1  10360  167  184  8284  133  147  7252  120  132  69-8 37-9 109 77-6 29.2 108 81.8 24.8 109  1.80  B  .,  1.80  B  M  6216  102  113  5' 1.80 8' 1.80  1.80  B  ..  5180  85  94  1.80  B  ..  8912  144  158  7' 6' 5" 8' 7' 6'  1.80  B  ..  7252  128  128  6216  101  111  5180  92  8272  84 118  118  7238  103  103  6204  89  89  £.170 6328  74  74  104  5424  90  1.80 1.80  1.80  B  ..  1.80  1.80  B  ..  1.75  1.60 1.38  C  1.75  1.60 1.38  c  1.75  1.60 1.38  c  5' 1.75 7' 1.80 6' 1.80  1.60 1.38 1.80  r,  ,1  B  I.  1.80  B  .1  VOLUME OF HEAPED BUCKET OF SCOOP -  " II  113  87.3 20.1 114 80.0 29-7 110 80.0 27.2  114 86.4 24.1 111 86.6 20.0 111 80.4 27.4 83.4 39-6 138 83.7 39-4 138  136  81.8 39.6  1 ?R 77 4 40 5 115 114 87.5 23.8 99 109 89.2 18.3  112 C U . F T .  N** -  DRAW FIGURES PLOTTED AND COLUMNS 1 6 , 1 7 , 18 CALCULATED FOR NO. OF SCOOPS DRAWN ' N .  SC  SCOOPS DRAWN.  -  1  o  A P P E N D I X  TABLES  2,3  AND  III  k  T A B L E  2.  REMARKS:  130  40  3-12  640  296  NIL  -  950  B  100  3-7  5  C  NIL  6  C  7  1  A  NIL  2  A  NIL  3 4  B  1 .22 2.56  1.6  26  66  Loosely  23.6  2.5 5.0  2.45  9.65  3.1  54  72  Vibrated  530  42.4  15-0  7.35  5.76  2.4  44  -do-  820  430  34.4  11.0  5.37  6.4  2.53  67 68  Tamped t h e S a m p l e W h i l e  -  150  46  3.68  1.25  0.61  6.02  68  Vib.  300  10.8  135  40  3-2  2.5  1 .22 2.62 1.618  26  58  -do-  C  300  10.8  260  80  6.4  5.0  2.45  2.62 1.618  26  58  -do-  8  D  NIL  -  420  130  10.4  5-0  2.45  64  -do-  9  E  1.76  650  300  24.0  15.0  7.35  4.24 2.06 38 3.26 1.80 32  10  F  -  640  290  23.2  10.0  4.90 4.74  11  F  50  1.8  620  280  22.4  11 .0  5-38  4.16  12  F  100  3.6  810  424  34.0  10.0  4.90  6.94  13  F  200  7-2  530  206  16.5  10.0  4.90  3-37  14  F  300  10.8  300  94  7-5  10.0  4.90  1.53  50 NIL  46 2.46 46  Packed the Sample. the Sample.  the Sample W h i l e  REPEAT OF  Forming.  '6'  61  Tamped t h e S a m p l e .  40  65  Tamped t h e S a m p l e W h i l e  2.04 38 2.64 48 1.84 32 1 .24 12  64  -do-  69  -do-  61  -do-  51  -do-  2.2  Forming.  EXACTLY.  Forming.  T A B L E  SIEVE  ANALYSIS (IN  \  %  OF  TABLE  SAMPLES 2,  OF  3.  USED  IN  APPENDIX  THE  TRIAXIAL  TESTS  III)  SIEVE \ A N A L Y S 1S  -0.625"  -0.525"  -0.371" -O.263"  -0.185"  -0.0328" -0.0232"  -0.065"  100%  -0.0164"  -O.0328"  TOTAL -0.0116"  DESCR.N. OF T E S T E D N . MATERIAL N.  +0.525"  A  40.56%  34.33%  14.00%  5.92%  4.05%  0.58%  0.56%  2858.60  B  45-74%  35.03%  11 . 2 0 %  4.06%  3.00%  0.52%  0.45%  2669.70  C  5.26%  6.62%  15-09%  17.10%  32.87%  9.70%  13.36%  2770.50  D  9-36%  13-94%  15.90%  15.12%  27-55%  7.97%  10.16%  2885-40  E  2.81%  6.22%  16.20%  18.82%  32.73%  9.52%  13.69%  2841.40  F  +0.371"  +0.263"  +0.185"  +0.065"  +0.0328"  +0.0232"  +0.0164"  +0.0116"  WEIGHT IN GRAMS  72.30%  11.00%  9.65%  7.05%  2772.80  T A B L E (ORE MATERIAL  'A'  32  65  'B  1  13  •c 'D' •E  1  ' F' 1  G  1  10.0  4. USED  IN  MODEL)  3  1.68  1 :30  60  1.80  1 :30  SCALE  25  27 60.6  14.4  1.75  1 :30  SCALE  22.5  60.7  16.8  1.68  1 :30  SCALE  24.6  23.7  11.0  21.8  7-7  1 .2  1.56  1:20  SCALE  0.7  45.6  25.5  17-4  6.7  4.1  1.56  1:30  SCALE  27.0  13-0  25.0  25.0  10.0  1.46  1:30  SCALE  SCALE  A P P E N D I X  TABLE 5 " DESIGN DATA FOR THE  IV  RECOMMENDED  LAYOUTS.  T A B L E SUMMARY  5.  DESIGN DATA FOR THE RECOMMENDED LAYOUTS,  Av.  23  to  AC  As.  Uj  X  r i  -  A^ Co  tty  —i  Co  C?  A. /3  ^  Co  *NT  to "V.  03  to  o\o  NT  AC  Or  A?  CO  10 A  20'  65  c  60'  126  86.  28.4  0-90 SC = 0::1  80'  20  90-200 SC = 1::1 80°  30 (1:20 SC)  20'  65°  60'  112  74.9  33.0  30  65  60'  124  89-3  28.0  0-90 SC = 0:1  80°  49  27.9  90-275 SC = 1:: 1 0-110 SC = 0::1  NIL  60  80'  78  SEE TABLE 6  80°  SEE TABLE 7  80<  95 98  1  30'  c  75  c  60'  121  87-4  110-130 SC = 2::1 130-260 SC = 1 40'  65°  60'  115  90.5  21.3  0-180 SC = 0::1 180-300 SC = 1:1  50'  55  c  60'  6'- 6'  112  50'  70'  60'  8'  110  68.5 78.4  79°  30'  109  87-3  T.S.L.C.  20. 1  0-200 SC  1 : :1  104  APPENDIX  110.  IV  CONFIGURATION - A STANDARD LAYOUT FOR 20-FT. ORE BODY - F.W. ANGLE 65° (ITEM NO. 20 AND 30 TABLE 1 OF APPENDIX III)  (TO  75°)  PRODUCTION JUMBO IN ORDER TO EQUALIZE THE WORK LOAD ON TWO BOOMS.  111. CONFIGURATION  B  STANDARD LAYOUT FOR 30 FT. ORE BODY (ITEM NO. 49 A B L E 1 OF APPENDIX I I) T  F.W.  ANGLE 65°  (TO  75°)  112. CONFIGURATION  C  STANDARD LAYOUT FOR kO FT. ORE BODY (ITEM NO 78 TABLE 1 OF APPENDIX l l )  F.  W. ANGLE 65°  (TO  75°)  113. CONFIGURATION  D  STANDARD LAYOUT FOR 50 FT. ORE BODY (ITEM NO. 95 TABLE 1 OF APPENDIX l l )  F.W.  ANGLE  55°  CONFIGURATION STANDARD LAYOUT FOR 50 FT. ( ITEM NO.  98 TABLE  E  ORE BODY -  1 OF APPENDIX  ll)  F.  W. ANGLE 70°  115. CONFIGURATION F STANDARD' LAYOUT FOR 20 F T . , F. W. ANGLE 75° AND ABOVE.  30 FT.  AND kO FT.  ORE BODY  116. CONFIGURATION G  STANDARD LAYOUT FOR 20 F. W. ANGLE 55° - 65°.  FT.,  30  FT.  AND kO FT.  ORE BODY -  CONFIGURATION H STANDARD LAYOUT FOR TRANSVERSE SUB LEVEL CAVING SUB LEVEL INTERVAL 30 FT. - S i p E SLOPES. 7 9 ° (ITEM NO 103TABLE IB OF APPENDIX I I )  16'  . 118. CONFIGURATION  I  STANDARD LAYOUT FOR TRANSVERSE SUB LEVEL CAVING SUB LEVEL  INTERVAL 30 FT -  SIDE SLOPES  79°  VERTICAL SECTION ALONG THE CENTRE LINE OF THE EXTRACTION DRIFT. FROM CONFIGURATION 'H'  CONFIGURATION J 119. COMPARISON OF LOADING 30 FT. LOADING  ORE BODY -  F.  W. ANGLE 650  INTENSITY 3 : 1 : :  (ITEM NO. 41  TABLE  INTENSITY  F.W.  : H.W.  1 OF APPENDIX  II)  CONFIGURATION K COMPARISON OF LOADING 30 FT. LOADING  ORE BODY -  F.  INTENSITY 1:1  (ITEM NOkO TABLE  120. INTENSITY  W. ANGLE 65° ::  F.W.  1 OF APPENDIX  :  H.W. II)  TABLE T e s t No.  33  (#85  t o #88  C u m m u l a t i v e number o f  of  TABLE  6.  1)  scoops drawn a r e  tabulated  DRIFT B H.W.  below:  DRIFT A F.W.  H.W.  F.W.  0 - 250  251 - 350 351 - 380  TABLE Test  No.  32  (#89  t o #92  C u m m u l a t i v e number o f  of  TABLE  7.  1)  s c o o p s drawn a r e  tabulated  DRIFT B H.W.  below:  DRIFT A F.W.  H.W.  F.W.  0-170  171 - 290 291 - 350 351 - 360 361 - 365 366 - 370 371 - 375 376 - 380 381 - 385  386 - 390 391 - 395 396 - 400 401 - 450  122. APPENDIX  FIGURE 14  Longitudinal with  Caving  - shows s e q u e n c e o f draw  s i n g l e e x t r a c t i o n d r i f t on e a c h s u c c e s s i v e  level. and  Sub L e v e l  V  F.W.  Ore body w i d t h 20', slash  S . L . I . = 60',  Longitudinal  angle  65°  80°.  (PP  FIGURE 15  F.W.  sub  Sub L e v e l  C a v i n g - shows s e q u e n c e o f d r a w  with  two e x t r a c t i o n d r i f t s  50',  S . L . I . = 60',  F.W.  120 t o 124)  on a s u b l e v e l .  a n g l e 55°  and F.W.  (PP  Orebody w i d t h slash  80°.  125 t o 127)  126.  14 M  14 0  14 P  127.  14  S  14  T  DRIFT A  nniFT ii . C O U P S I) 11 AW  s cool's  nv  H\V  II ii  AW;  HW  0  0  0  15 A  1)111 F T  I1BIF  scours II nw 0  \  S C O O P S 1) 1 1 AWN  •  HW  t  0  15 C  0  FW  30  15 G  15 H  15 K  15  L  131. A P P E N D I X  VI  DETAILED GEOLOGY  Granduc M i n e s ' o r e o c c u r s with  an a v e r a g e w i d t h  e x t e n t o f about  in long,  o f kQ',  2,500'.  series  t h i c k between which  faults  The o r e b o d i e s  feet wide,  the a n d i s i t i c footwall  are generally a t 90°. t h e wings  15 f e e t  pre reserves  wall,  ore control  is  portions  in width.  some p a r t s  in " C " orebody  dip at  a r e up t o  120  a n d o t h e r A , B a n d B] o r e b o d i e s A l m o s t 50% o f t h e t o t a l  minable  portions.  (1966) a r e 43 x lo6 t o n s a t a v e r a g e ].73% c u .  10% d i l u t i o n , o r e r e s e r v e s  A typical  500'  zones.  of " C " orebody  t o 50 f e e t  (silicious  i s about  The s t r u c t u r a l  d i p p i n g a t 70° a l t h o u g h Thick  l i e in a  lime stone hanging  i n N o . 1 M i n i n g Zone a r e t i e d up i n t h i n  Geological  They  and d i s -  folded phyllonites  and t h i n  greywackes.  and s h e a r e d crumpled  whereas  between  tonnages  With  and m a g n e t i t e .  bodies  3,500' a n d v e r t i c a l  i n a g r o u p c a l l e d t h e m i n e member, w h i c h  50 - 55° a n d o t h e r s  vary  chalcopyrite  i s s u c c e e d e d by a l t e r e d  folds,  length of  l e n s e s a r e composed o f s t r i n g e r s  o f weakly metamorphosed and s t r o n g l y  metasediments),  conformable tabular  combined s t r i k e  These  seminations of p y r r h o t i t e ,  irregular  are approximately  s e c t i o n and p l a n o f t h e o r e b o d i e s  h7 x 106  t o n s a t 1.49% c u .  a r e a t t a c h e d on P a g e  132.  O  O o 11 0 00  E  II 0 0 0 E  4U  S  Volcanics  HW, F 2 Vo'cani-cs  s  WTftlge  \  y  0  "Ch"  M e l a sediments c E n  Mela sediments 10 5 0 0 E  10 5 0 0 E  AS" Fault L imeslone  A  FW A " Fault  L E G E N D  •  0)  c o  ORE  0>  Limestone  FW  ZONES  DYKE  E  METASEDIMENTS V 0 L C AN ICS  3630  PLAN SURFACE  o o  01  o o  LIMESTONE O  o  If)  100  

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