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The decomposition of pyrite and other sulphide minerals by sulphur chloride McElroy, Roderick Owen 1972

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TEE  DECOMPOSITION  SULPHIDE  MINERALS  OF  PYRITE  AND  BY  SULPHUR  OTHER  CHLORIDE  BY  RODERICK  OWEN  McELROY  B.Sc. (Honours C h e m i s t r y ) , U n i v e r s i t y M . S c . , M o H a s t e r U n i v e r s i t y , 1967  A  THESIS THE  SUBMITTED  IN P A R T I A L  REQUIREMENTS DOCTOR  in  FOR  OF  of Alberta,  FULFILMENT  THE DEGREE  OF  OF  PHILOSOPHY  the Department of METALLURGY  We  accept  required  THE  this  thesis  as c o n f o r m i n g  to the  standard  UNIVERSITY  OF  March,  BRITISH 1972  COLUMBIA  1965.  In p r e s e n t i n g t h i s t h e s i s  in p a r t i a l  f u l f i l m e n t o f the r e q u i r e m e n t s  an advanced degree at the U n i v e r s i t y of B r i t i s h C o l u m b i a , 1 agree the L i b r a r y I further  s h a l l make i t f r e e l y  available for  agree t h a t p e r m i s s i o n f o r e x t e n s i v e  r e f e r e n c e and copying of t h i s  It  i s understood  that c o p y i n g o r  thesis  permission.  Department o f  Metallurgy  The U n i v e r s i t y o f B r i t i s h Columbia Vancouver 8, Canada  Date  M a y 4,  1972  or  publication  o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l not be a l l o w e d w i t h o u t my written  that  study.  f o r s c h o l a r l y purposes may be g r a n t e d by the Head o f my Department by h i s r e p r e s e n t a t i v e s .  for  ABSTRACT  The minerals  reactions of pyrite with  liquid  investigated extraction  i n an a t t e m p t  of metals  sulphide  minerals  sulphur)  as b o t h  purpose,  flotation  powders  percent  "  reacts  2  to react  40  %  2  found  S. 2  t o be  antimony, zinc  ) and  S C1 2  completely  c a t a l y z e d by  significantly  2  Cu,  Mo,  S C1 2  f o r the  dissolved  For  this  mineral  reacted  at  temper-  containing  2  been  e t c . from  synthetic  with  2  and  solid  with  10  0-40  metal  2  2  wt  2  or S C 1 2  wt  %  dissolved  containing  2  Chalcopyrite solutions  completely % S,  Pyrite  25-40  sulphur. 2  chlorides  sulphur.  S C1  S C1  (PbS) r e -  and  containing  with  this  was  distilled  reaction  was  the n a t u r a l i m p u r i t i e s  silver,  Pyrrhotite  marmatitic  only  partially  indicated  attacked  galena  containing  of Investigations with (MoS )  2  a process  were  with  containing  were  2  sizes  (PbS) r e a c t s  and b i s m u t h .  molybdenite  and  dissolved  of dissolved  concentrate  A series  be  2  ( S C 1 ) have  and r e a c t a n t .  t o form  2  sulphide  sulphur.  partially  Galena  or S C 1  <-  with  but only  found  2  2  , PbCl  % or less  S C1  S C1  other  or without  2  10 wt  wt  (with  2  chalcopyrite (CuFeS )  completely  sulphur,  40-150°C  dissolved  excess  , CuCl  2  particle  weight  (FeCl  S C1  F e , Pb,  concentrates  i n the range  with  as  the s o l v e n t  of various  Pyrite,  chloride  to develop  such  using  atures  acted  sulphur  CFeS^) and  by  ( F e S ) and a  d e c o m p o s e d by  sphalerite  that  these  S CI .  S C1 . 2  2  (ZnS) and  minerals  could  not  -  In be  a l l cases,  crystallized  i i i  sulphur  -  produced  in stoichiometric  i n these  yield  by  reactions  cooling  can  the  s olvent. A and  geometric  chalcopyrite  interpret and  for  the  the  basis  f o r the  sulphur  energies  treatment  proposed.  with  the r e a c t i o n  activation On  model  data  chloride  and  f o r the  of this  reactions  to  has  of p y r i t e , been  calculate  reactions  used  galena  and  to  specific  rates  concerned.  investigation, potential  of p y r i t e ,  galena,  molybdenite  processes are  -  iv -  ACKNOWLEDGEMENTS  The Dr.  E. P e t e r s  study. and  author  Other  staff  their  have  help  Canada  for his interest members  support  i n many  acknowledged.  and g u i d a n c e graduate  areas  thanks  to  in this students,  of the study  -  appreciated. from  grants  University  h i s sincere  of faculty,  assisted  through  Metallurgy, fully  to express  i s sincerely  Financial of  wishes  the National  t o members  of British  Research  Council  of the Department  Columbia,  i s grate-  of  -  TABLE  V -  OF  CONTENTS  Page 1.  INTRODUCTION  1  1.1  General  . .  1  1.2  Methods  of Pyrite  .  2  1.21  Roasting  1.22  Chloridizing  Roasting  1.23  Chloridizing  Volatilization  1.24  Hydrometallurgy 1.241  1.242  2 3  of Pyrite  . . .  4  . . . .  5  Hydrometallurgical Treatment of Pyritic Material  5  Rate C o n t r o l i n Hydrometallurgical Decomposition of  1.3  Treatment  Sulphides  1.25  Chlorination  1.26  Summary  6  Processes  8 10  Background t o the Present Investigation 1.31  1.32  Low T e m p e r a t u r e of P y r i t e Properties 1.321  1.322  1.323  1.33  11  Chlorination  of Sulphur  11 Chloride  .  12  C h e m i c a l and P h y s i c a l Properties of Sulphur Chlorides  12  Sulphur-Sulphur Solutions  14  Chloride  Physiological Properties of Sulphur C h l o r i d e . . .  Thermodynamics o f C h l o r i n a t i o n of Metal S u l p h i d e s  15  15  -  v i  -  Page 1.34  1.4  2.  AND  2.3  3.  METHODS  19 19  2.11  Natural  2.12  Synthesis Chemicals Other  Sulphide  Minerals  of Minerals  21  2.21  Sample  Preparation  2.22  Experimental Procedure  AND  and  Apparatus  . . .  3.12  Apparatus  and 22  Methods  24  DISCUSSION  27  Reaction of Pyrite Sulphur Chloride  27  with 27  Reaction of Pyrite with SulphurSulphur Chloride Solutions . . . . 3.121  3.122  3.123  3.124  E f f e c t of Sulphur  21 21  D e c o m p o s i t i o n o f P y r i t e and R e l a t e d Compounds by S u l p h u r C h l o r i d e 3.11  19  and  materials Methods  Analytical  . . . .  19  Experimental  RESULTS 3.1  18  Materials  2.13 2.2  15  Objectives  MATERIALS 2.1  Thermodynamics of O x i d a t i o n of Metal C h l o r i d e s  30  Dissolved 30  Effect of S t i r r i n g R e a c t i o n Rate A Geometric Reaction  Model  on  the 32  of the  Results of Experiments Sullivan Pyrite  32 , on 35  -  v i iPage  3.125  3.126  3.13  3.14  3.15  3.16  The A c t i v a t i o n Energy  42  Reaction of Pyrite a D i f f e r e n t Source  from . . . .  R e a c t i o n o f N a t u r a l and Synthetic Pyrrhotite Reaction Chloride  of Anhydrous with Sulphur  44  Ferrous Chloride  Reactions of Metallic Sulphur C h l o r i d e  Iron  Summary  .  51  . .  3.2  The R e a c t i o n  of Pyrite  3.163  The R e a c t i o n Pyrrhotite  of  The R e a c t i o n s M e t a l l i c Iron  Decomposition 3.211  3.212  3.213  3.214  3.215  3.22  53  3.162  Decomposition o f Other Sulphur Chloride 3.21  . .  57  58 of 59  Sulphides  by 60  of Galena  60  R e a c t i v i t y o f N a t u r a l and Synthetic Galena  60  Determination Catalysts  60  of  Results of Experiments on Pine Point Galena . . . .  62  Calculated Energies  66  Activation  Miscellaneous Observations  Decomposition o f C h a l c o p y r i t e by Sulphur C h l o r i d e 3.221  53  of  Observations.  3.164  50  with  Summary a n d D i s c u s s i o n o f Experiments on I r o n Compounds 3.161  44  Results Phoenix  o f Experiments on Chalcopyrite . . .  68  68  68  -  viii  Page  3.222  3.223  3.23  3.24-  3.3  The C a l c u l a t e d t i o n Energy  73  Qualitative Observations on O t h e r C o p p e r Minerals .  Decomposition of Zinc by S u l p h u r C h l o r i d e  of  73  76 for a  Reaction  Me c h a n i s m The R o l e  3.33  Surface  3.34  3,4-  3.5  76 of Sulphur  77  Reactions  79  3.331  D au t ri v eC h lR oe ra i ct o fi s sS ou cl ip h di e o n.s . . .  79  3.332  Associative Reaction of Sulphur C h l o r i d e . . . .  80  Models f o r Metal S u l p h i d e Sulphur C h l o r i d e Reactions  E l e m e n t a l Sulphur from of Metal S u l p h i d e s  3.51  of  Useful Properties Chloride  Sulphur 3.521  3.523 3.53  Potential  86 Sulphur 86 Uses f o r  Chloride  87  Pyrite  3 . 522  87  Galena  87  Molybdenite  Problems Chloride  80  83 Uses f o r  Specific  . . . .  Chlorination  Potential Metallurgical Sulphur Chloride  3.52  75  Experimental  Requirements  3.32  73  Sulphide  Decomposition of Molybdenite by S u l p h u r C h l o r i d e  Interpretation Results 3.31  Activa-  i n t h e Use o f  89 Sulphur 90  -  i x Page  4.  CONCLUSIONS  .  5.  SUGGESTIONS  FOR  91 FURTHER  WORK  .  94  REFERENCES  95  APPENDICES  99  LIST  OF  FIGURES  Figure 1  Page Schematic  Diagram  of the  Experimental  Apparatus 2  3  23  Reaction  of Pyrite  Chloride  a t 133°C  Effect  of Pyrite  at  (.Substrate:  Effect FeS  5  6  7  40  wt  40  Plot  of r  wt o  + 2  [l-(l-R) +  In  %  2  Reaction  S.S C1 2  o f -70 wt  Absorbed  %  -70  m  + 100 2  33 Sullivan  FeS  2  36 ] vs m  Time  f o r the  Sullivan  FeS  2  .  + 100  Electron  of  2  m  270  2  Plot  2  mesh  2  1/3  S.S C1  Arrhenius  S.S C1  + 100  Chloride  the Reaction  270  % S.S C1  o f -200  wt  on 2  Reaction  %  -70  % S.S C1  o f -200  with  40  Sulphur  31  of S t i r r i n g  Magnification 9  with  on t h e  2  Reaction  40  Sulphur  FeS >  with  2  with 8  Sulphur  Reaction 133°C  Pure  28  of D i s s o l v e d  Sullivan 4  with  m  Sullivan  FeS  2  39  2  Image  = 240  x  Micrographs,  .  41  f o r the Reaction  Sullivan  37  Pyrite  with  of 40  wt 43  -  xi -  Figure 10  Page Plot  Cl-(l-R)  of r  Ivs  1  Time  f o r -70  o +  100  m  Sullivan  Reacted  with  40  and Noranda wt  % S.S C1 2  Pyrites at  2  119.9°C 11  -70  45  + 100  Pyrites 12  2  13  Reaction and  14  S C1 2  2  17  Plot  % S.S C1  Film  Sullivan  2  2  40  wt  FeS  with 48  % S.S C1 2  (a)  2  on  52 Iron  Reacting 54  o f -150  o  Catalyzed Point  m  2  with  of r  46  ( b ) a t 133°C  2  Reaction  Plot  + 200  o f Fe w i t h  S C1  Galena 16  wt  G r o w t h o f FeS with  15  40  and Noranda  Leaching  o f -140  and  2  Sullivan  Before  Reaction S C1  m  10  +  200  wt  Point  % S.S C1 1/3 [1-Cl-R) ] vs Time 2  Reaction  Galena of r  m Pine  with  o f -150 10  [1-(1-R)  1 / 3  wt ]  63  2  f o r the  + 200  % S.S C1 2  vs  m  Pine 64  2  Time f o r  o Uncatalyzed Point 18  Galena  Arrhenius  Point  S.S C1 2  2  with  Plots  Uncatalyzed Pine  Reaction  o f -150  10 wt  t 200  (b) Reactions and  Pine  % S.S' C I  for Catalyzed  Galena  m  ( a ) and  o f -150  10 wt  65  + 200  m  % 67  -  xii  -  Figure 19  20  Page Percent  Reaction  Phoenix  CuFeS  Plot  of r  vs  Time  i n 40  2  [1-Cl-R)  wt  '  f o r -100 %  S.S C1 2  ] vs  +  140  m 70  2  Time f o r  o -100 40 21  wt  140 %  40  +  wt  %  Rhombic from  m 2  CuFeS  in .  f o r Reaction  Phoenix  CuFeS  2  with 72  Metal  Sulphur  71  of  2  f o r the Reaction with  2  2  Plot  S.S C1  Chloride 23  Phoenix  2  140  Models  m  S.S C1  Arrhenius -100  22  +  of  Sulphur  Sulphides  Crystals  S.S-C1. S o l u t i o n  81  Precipitated 85  -  xiii  LIST  OF  -  TABLES  Table 1  Page Enthalpy  and  Reactions with 2  S C1 2  Rates with  4  5  6  2  %  Effect  a t 70Q°K  of Sullivan  S. S C 1 2  . . . .  38  2  FeS and  FeCl  2  Solutions  50  FeS, F e C l  2  Rate  Rate CuFeS  and  2  Fe 55  Extended  FeS, F e C l  S. S C 1 2  2  Time and  Reaction Fe  in  S  C  1  2  Rates 2  a  n  d  . .•  2  of Various  56  A d d i t i v e s on  of Synthetic  PbS  the  Rate  with '. .  of Reaction Galena  o f 150  with  of Reaction 2  i n 40  Reaction  17  Pyrite  2  Point  10  of Oxidation f o r  Chlorides  of FeS ,  Reaction  2  9  2  and  FeS ,  S C1  Sulphides  S'CI  40 wt  8  %  2  Initial  of  Energy  of Synthetic  Reactions  for  7  wt  S.S C1  with  Metal  16  Metal  Reaction  Values f o r  2  of Reaction 40  with  Energy  of Selected  C a l c u l a t e d Free Selected  3  Free  wt  10  wt  +  200  m  %'S.S  61  Pine  C l  2  . . . .  66  (Penetration) of %  S.S C1 2  69  2  of Sphalerite with  S C1 2  2  . . . .  74  -  xiv  -  Table 11  Page Chlorine  Content  of  Precipitated  Sulphur 12  Summary Energies  86 of  Rates  and  Activation 92  -  1.  INTRODUCTION  1.1  General Pyrite  tain Pb,  (FeS2)  significant  ores  1  and c o n c e n t r a t e s  quantities  treatment  (1).  of the entire  Pyrite itself able  Recovery  ( 2 ) and a d j a c e n t . t o  sulphides  quantities.  Pyrite  sulphur  in  production.  pyrite  have  of these  been  mineral,  Non-ferrous  metal  chlorides  from  towards  improvement  treatment of  elemental  many  of these  studies  from  (4) t o i s used  associated (5)  or  with after  non-ferrous  has been  currently  o f new  pyrite  (9-18).  valu-  materials.  of processes  sulphur  more  which  (4,8) of  amount o f r e s e a r c h  and t o development  by  i n large  leaching before  o r by v o l a t i l i z a t i o n roasted  con-  chemical  quantities  oxide  metals  roasting,  considerable  requires  available  i n large  (6,7)  A  to physical  or i n t e r s p e r s e d with  by  ( e . g . Cu,  f r e q u e n t l y found  (SO^) and i r o n  recovered  con-  concentrate.  i s treated  dioxide  metals  metals  ( 3 ) so i t i s r e a d i l y  produce iron  n o t amenable  pyrite  i s a common  frequently  of non-ferrous  Z n , Co, A u , Ag) i n f o r m s  centration  -  used  processes.  has been  directed  for pyrite Production  the subject of  -  1.2  Methods  1.21  of  large  amounts  sulphides oxides  by  (or  Treatment  2FeS  (2)  MS  (3)  S0  (4)  MO  to  (5)  etc.,  and  tionally difficult roasting not  pyritic  oxidation  +  +  2  i  +  S0  +  Fe  any  recoverable  the  material  of  and  metal  4  °2  S  sulphur elimination (M = C u , Z n ,  2  etc.)  sulphation  e l i m i n a t i o n of  by  MO.Fe  Og  form  a  spinel  insoluble are  the  M0.Fe  (more an  residue  in  production.  u 2  3  where  correctly  undesirable  metal  unsuitable  sulphur  reaction:  structure -  conventional  leached iron  treat  decomposes  dioxide  3  (19)  non-ferrous by  to  reactions:  +  S0  the  d i s s o l v e ) and  since  2°3  complete  ->  acid  overall  S0  formation  0  Roasting  sulphur  +  i s used  MSO^  u s u a l l y having  to  the  MO  X  3  compounds  termed  form  t  2  leaching,  material.  F e  roasting for  ferrite  -  0  acid  2  +  j  by  to in  |°  |o  +  MO  Ferrites  of  2  Dead leads  followed  sulphates)  (1)  make  -  Roasting Roasting,  is  Pyrite  2  in  acid for  the  M  are  are  product  form  as  Cu,  a  Zn,  conven-  they  leaching use  =  of and raw  very  of ferrite may  -  Sulphating ferrous oxide dead  metals  roasting  Thus,  leaves  more  some  as t h e form  of the non-ferrous  solubilizes sulphide  purification  and t h e i r o n  iron  sulphatizing  oxide  some  metals  ferric than  of the iron  sulphur  i n the  of the leach residue  of  may  and  calcine.  liquor be  non-  may  be  contaminated  sulphur. To  normally points  carried  oxide  roasting actors  prevent  agglomeration,  films  may  be  reactions proceed  are required.  and  leached  (by  sintering  roasting  out at temperatures  o f the (.solid) r e a c t a n t s  tective  1.22  - selectively  retaining  but also  extensive  required,  iron  while  - solubilizes  frequently  with  roasting  3 -  reactions are  below  the melting  or products.  formed  a n d i n some  slowly,  so l a r g e  A l s o , m a t e r i a l which  in a finely  divided  or p e l l e t i z i n g )  Thus,  form  before  must  cases  pro(20)  capacity r e has been  be  roasted  agglomerated  use i n c o n v e n t i o n a l  production.  Chloridizing  Roasting  Chloridizing  roasting  treatment  of p y r i t e .  for  sulphur  elimination  the  presence  o f sodium  chlorine.  Non-ferrous  chlorides  and r e c o v e r e d  However,  leaching  (6,13,14)  In t h i s  i s also  process,  and t h e c a l c i n e chloride metal  or other  oxides  pyrite i s then  used  i n the  i s roasted roasted i n  low c o s t  source  are converted  by  leaching  the c h l o r i d i z e d  of these  calcines  has proven  of  to calcine.  difficult (4),  -  agglomeration  of  the  residue  be  used  and  a  i s to  complex  chlorides  1.23  leach  and  sodium  i n the  this  type  residues is required  for conventional iron containing  sulphate  is  used  of  of  with  calcium chloride,  pelletized,  kiln  to  volatilize  of  gas  i n hydrogen  low  chloride  the  at  ization  of  process  i s best  arsenic  since A  remove  In  the  tion  green  by  (4).  In a  stream  heated  requires  hydrolysis  of  metal a  heating  calcium  occur.  Also,  calcines  low  in sulphur  only  metals  reaction  from of  zones  dried  second  from  process  modification  and  zone,  a i r and  partially  method  of  eliminated.  chlorine  pyrite  In  i n d u r a t e d by non-ferrous and  shaft first combus-  metals i n the  (Cl^) calcine.  the hot  and  is in  gas  process, a  i s used.  chlorine,  this  and  calcine  pelletized this  volatil-  chlorinating  pyrite  uses  mixed  in a  not  are  pro-  is  will  metals  of  and  a  and  This  the  calcine  non-ferrous  process  different  are  In  chlorination  elements  pellets  gases.  removed  to  non-ferrous  three  metal  another  calcine.  dried, the  where  metals  suited  recent  with  This  temperatures  non-ferrous  most  of  is  (8), pyrite  minimize  substantially  to  zone,  to  these  i n Germany  furnace  and  non-ferrous  volatilizing use  i n Japan  material.  low  mixture  (4,8,21)  pyrite  cess  content  production,  produced.  volatilization treatment  chlorinate  a  i f the  Volatilization  Chloridizing used  -  leach  liquor  Chloridizing  method  fine  4  are final  -  zone  the p e l l e t s  metals of  are a i rcooled.  are eliminated  gas, green  removal  calcium  to the p e l l e t s . roasting  convert  the p y r i t i c  product  i s useful  sulphur  product  processing  which  I s more  sulphuric  desirable easily  acid,  have  a local  However,  a more  treatable  would  transported  f o r the  and i s r e a d i l y  This  acid  the processing  sulphur  converted  they  sulphur  be e l e m e n t a l  than  -  (SO ) .  f o r sulphuric  a r e f a r from  product  feature  dioxide  markets  and  by a d d i t i o n o f  a common  market  where  volume  t o the furnace,  to sulphur  CH^SO^) e x i s t s . of pyrite  non-ferrous  i s not inhibited  procedures  where  the  easily  p e l l e t s , c a n be c h a r g e d  and a r s e n i c  site,  Thus  i n a small,  sulphur  All  5 -  sulphur  dioxide  to other  or  sulphur  compounds.  1.24  Hydrometallurgy  of P y r i t e  1.241  Hydrometallurgical  Treatment  Hydrometallurgical  methods  non-ferrous  sulphide  Cupriferous  pyrites  extraction,  and c o p p e r - , l e a d - , a n d  leached  by aqueous  significant  attack  Pyrite leaching by  have  ferric  been  heap  action  pressure  (28),  been  leached zinc  chloride  on t h e p y r i t e  oxygen  have  of  sulphides  present  or e l e c t r o l y t i c  pyrite.  have  been  without  (23,24).  i n an a q u e o u s with  to leach  (5) f o r copper  solutions  (18),  Material  used  i n the presence  c a n be d e c o m p o s e d  under  bacterial  minerals  of P y r i t i c  environment  chlorine  by  (25,26,27),  oxidation (29).  -  Up  to  50%  to  the  of  elemental  sures,' but leaching  aqueous  form  leaching  leaching  o x i d a t i o n and pyritic  of  pyrite  in acid  or  entirely  Thus,  pyrite  be  under  bacterial  sulphur  can  converted  oxygen  pres-  chlorine  to  can  sulphur be  (VI)  decomposed  systems.  of  sulphate  pyrite  otherwise  leaching  by  bisulphate).  Ferric  but  content  anodic  or  -  sulphur  converts  (sulphate in  the  6  are  the  solutions  are  used  iron  and  difficult  to  in  resulting  dump  sulphur convert  or  from  in-situ  products to  oxidizing leaching  of  (28)  pyrite  commercially  useful  forms. The elemental  difficulty form  i n an  unique,  since  such  pyrrhotite  as  CZnS),  galena  verted  to  tions  the  elemental  trast,  pyritic  verted  to  1.242  Rate  the  oxidizing  aqueous  sulphur  (PbS)  containing  in  (FeS), and  of  sulphur pyrite  other  aqueous  or  chlorine  apparently form  sulphides  by  to  minerals  sphalerite can  be  oxidation with  cannot  i n aqueous  (24,26). be  the  almost  sulphide  c h a l c o p y r i t e (CuFeS^),  ion  elemental  in  makes  nickel-cobalt  ferric  Control  system  content  sulphur  sulphur  pyritic  In  completely  consoluconcon-  systems.  H y d r o m e t a l l u r g i c a l Decomposition  of  Sulphides The of  rate  sulphides  transfer  of  can  controlling be  oxidant  grouped from  the  steps into gas  for five to  aqueous general  the  liquid  decomposition classes phase,  (30):  -  7  -  transport  of reactants  or products  across  transport  of reactants  or products  through  film, tion  heterogeneous of  the rate  a leaching  consumed rate  as f a s t  When  reaction  linear  k i n e t i c s are observed  usually  characterized  energy,  and a s t r o n g  (30).  An e x a m p l e  When  of this  a reaction  can only  i s rate  across  a  controlling,  (26) and t h e r e a c t i o n i s  type  product  mechanism ferric  of reaction of control  activation  rate  on  stirring  i s t h e aqueous  Reactions  i s insoluble  of this  surface.  i n the  has been  product  may  When  occurs,  the  this  reported  solutions. parabolic  this  of  Under  chalcopyrite  these  condi-  k i n e t i c s , and t h e r a t e  stirring. i n which  the rate  reaction  determining  exhibit  high  step  heterogeneous  surface  tion  and a r e i n s e n s i t i v e t o s t i r r i n g ( 3 0 ) .  energies  layer.  ( 3 2 ) t o be t h e r a t e  f o r the decomposition  displays  leaching  insoluble  by d i f f u s i o n t h r o u g h  sulphate  the reaction  insensitive to  layer  proceed  a diffusion layer  aqueous  then the  of pyrite (25).  on t h e r e a c t i n g  controlling  solution)  or product  layer)  dependence  be  formed  the gas phase  by a low ( ^ 5 K c a l / m o l e )  a protective  is  combina-  i s constant (31).  (Nernst  solution,  tions  or a  from  into  of a reactant  diffusion layer  in  insoluble  c o n t r o l l i n g ( i . e . oxygen i s  as i t c a n be t a k e n  transport  chlorination  transfer  i s rate  liquid  Such  at the surface,  o f oxygen  mixture  of the leaching  reaction  an  layer,  these.  When into  reaction  a diffusion  apparent  is a activa-  -  Mixed reaction  reaction  proceed  control  In t h i s  cause  i n the rate  in  the aqueous  rate  1.25  Chlorination direct  been  pyrite  i s reacted  temperature is  eliminated  FeS  +  2  Chlorination of  sulphur  reaction sulphur  by  2  Cg)  above  from  cannot  Hohn  b u t a t 20°C  et a l .  for pyrite  (9).  mixed  gas i n a f l u i d  point  treatment  In t h i s  process,  bed a t a  of sulphur.  Sulphur  reaction:  FeCl  +  2  the b o i l i n g  |  point  5^  (g),  as a gas e n s u r e s  be  by a l a y e r  stopped  1-8)  and  that  of s o l i d  of the reacting  chloride  (x =  of sulphur  the system  metal  reaction  i s observed.  chlorine  -*•  on t h e s u r f a c e The  For example,  (33) the  45°C,  process  the b o i l i n g  by t h e  C l  of galena  step.  can  Processes  with  above  of a  i n temperature  determining  control  two s t e p s  at a p a r t i c u l a r  a change  chlorination  developed  when  rates  controlled/above  and t r a n s p o r t  A has  case,  chlorination  i s transport  chemical  occurs  at comparable  temperature. a change  8 -  removal  the  or  liquid  sulphide.  product' o f t h i s  reaction  i s then  oxidized:  2FeCl  to  2  +  regenerate  j  0  2  +  chlorine  Fe 0 2  3  +  and produce  2C1  2  a mixture  of iron  oxide  -  (Fe  0  ) and  chlorine the  9  -  soluble non-ferrous  consumed  non-ferrous  by  the  metals  metal  process  -  the  chlorides.  i s that  remainder  The  associated  only  with  recycles within  the  system. Problems  in  this  temperature  sulphur  the  and  system,  vapour,  dust  Thermodynamic have  shown  that  chloride  selective chlorine  pyrite  or at  found  problem pears  the  or  ferric  may  pose  than  of  handling  back  of  with  mixing  the  the  high  through  Ingraham  (34,35)  cobalt-,  nickel-,  chlorine  gas  favoured to  and  iron  or  that  oxide  involving  chlorine boiling  various  gas  and  chlorination or  point  from of  a  reaction  cases.  distillation  require  and  (10-18,25,27,36-41),  i n many  (14)  product  product or  fused  sulphur  significant  sulphur  but  the  amounts  transfer  or  product  sulphur  produces  sulphur  ap-  methods  sulphur  (36)  mass  metal  of  (40).  i n heat  sulphur.  of  Suggested  of  solid  ferric  products  problems  elemental  of  feasible.  below  combustion  methods  combustion rather  include  and  by  processes  literature  chloride  chlorides,  iron-,  chlorides  sulphides  unresolved  separation  tillation  other  separation  be  of  Pilgrim  sulphides  iron  temperatures  in  of  to  other  of  and  zinc  of  i s thermodynamically  chloride are  s t u d i e s by  o x i d a t i o n of  to  the  control.  i s thermodynamically  References of  include  prevention  chlorination  manganese-,lead-,and ferric  process  of  Dis-  heat  containment, dioxide  input and  -  Where required,  of  of  demonstrated  chloride hot  can  acid  crystallize  be  metal  of  the  temperature  to  present  separation  1.26  sulphur,  the of  has  most  been  in  is  chloride  of by  (15)  solution  Anhydrous  followed  not  suggested  aqueous  chlorination  solutions  the  recovery high  by  product  sulphur—metal  sulphides  chloride  in  the  (25-27,33,38,39).  chloride  However  of  chloride  reactions  produced  lead  -  metal  leaching  chlorination  chlorination  been  in  anhydrous  aqueous  products and  an  10  has  lead  lead  sulphide  cooling  to  (33).  chlorination iron  oxide,  process  of  and  pyrite, chlorine  proposed  by  p r a c t i c a l approach  Hohn  to  the  where is  the  desirable,  et  al.  appears  problem  of  products.  Summary In  designed mineral  general, to  in  are:  iron  trate  of  processes  recover  commercially oxide  (free  non-ferrous  processing, For  a l l the  and  from  metals  pyrite  in  sulphur  (from  elemental  sulphur  is  easily  converted  into  other  forms.  of  harmful in an  a  The  form  may  pyrite of  suitable  be  for  further  at  a  form.  production  and  Decomposition metals)  concen-  desirable,  transportable  products  a  useful  plants,  are  the  desired  impurities),  economically  pyrite)  non-ferrous  of  components  forms.  processing  elemental  solubilization  treatment  valuable  useful  sulphur  future  for  of  can  since be  readily  pyrite  faster  of  rate  (or than  -  that  attainable  with  11  present  -  roasting  methods  would  also  be  desirable. All  the  production pyrite.  of  processes sulphur  However,  associated  with  Background  1.31  Low  sulphur, from of  tion be  iron  to  be  metal  or  mineral  to  to a  be  in  metals  have  the  the from  problems  Pyrite  production  non-ferrous  temperature  chlorides  and  (low  second  stage  iron  could  be  (VI)  of  so  use  iron of  sulphur a  process  iron  from  of  separawould  oxide  chlorides  Chlorination  (26)  a  to  metal  entire  concentrate chlorination  such  separated  the  elemental  temperature)  chlorides  Non-ferrous  of  metal  low  leaching.  sulphur  of  via  converts  and  would  oxide  pyrite  in  content  of  non-aqueous  by  the  solvent  appropriate. Initially,  were  reacted  (CC1  ).  chlorine the  and  The  o x i d i z e d and  solution  but  useful  Investigation  Chlorination  for recycle.  aqueous  seemed  processes  Present  o x i d a t i o n of  volatilization  are  d e r i v a t i v e s ) and  these  route  to  sulphur.  chlorine  Its  of  the  oxide,  seemed  selective  not  to  Temperature  pyrite  of  most  appealing  pyrite  (or  above  them.  1.3  An  described  with  This at  low  pyritic  samples  of  chlorine  work  showed  temperatures sulphur  was  a  pyrite  dissolved that in  flotation in  pyrite a  carbon  tetrachloride  is reactive  non-aqueous  converted  concentrate  to  to  environment,  sulphur  chloride  -  (S^Cl^)  rather The  into  that  this  Properties  1.321  Chemical Sulphur  contacting  and  may  melting  sion  to  properties  (22°C)  i s twisted  metal  C  1  boiling  of Sulphur  The  Chlorides  prepared  chloride  point  viscosity sulphur S-S  S-S-Cl  specific cal/g,  (18°C)  chloride  and S - C l bond angle  giving  Some  (42,43) a r e :  138°C, 64.6  (42).  gravity  surface  i s reported  ten-  2.015 c p s . has t h e s t r u c lengths  are  i s 103° and t h e molei t a structure  similar  peroxide.  Chloride  by  sulphur:  distillation  of vaporization  The  of p y r i t e  sulphur.  i s conveniently  fractional  phase,  and  2  out of plane  of hydrogen  oxides:  2  of sulphur  (44).  a n d 1.99A.  Sulphur  by  S  section)  solvent  - conversion  Properties  dynes/cm,  the vapour  Cl-S-S-Cl  that  U  -82°C,  40.78  a good  gas and e l e m e n t a l  +  2  1.6733, h e a t  2.5A., cule  4C1  be  Ccf. n e x t  Chlorides  (S2CI2)  Chloride  point  In ture  +  might  and e l e m e n t a l  and P h y s i c a l  chlorine  chloride  reaction  of Sulphur  be p u r i f i e d  physical  (20°C)  material  chlorides  1.32  sulphur.  of s u l p h u r  f o r the desired  metal  Sg  elemental  properties  suggested reactant  than  12 -  (45) to r e a c t  with  -  2M0  and  +  2  S  C  1  2  13 -  2  2MC1  +  2  S0  +  2  3S  sulph-ldes:  ZnS  +  S C1 2  and  Is r e a d i l y  and  hydrogen  such  forms  AlClg.2S C1 2  A1C1  o  .SCI  chloride  z  at least  (46).  3S  (.44) t o s u l p h u r ,  tetrachloride  but this  2  +  2  sulphur  but i s m i s c i b l e with and e t h y l e n e  one a d d u c t  with  Reaction  of sulfanes  chlorosulphanes  dioxide,  nonpolar  solvents  chloride.  a Lewis  m a t e r i a l decomposes  (42) produces  reactions  Sulphur  acid  -  on h e a t i n g t o  (HS H) w i t h n (S^Cl,^,  sulphur  n = 3-8) by  o f the form:  2S C1„ 2 2  +  0  These  hydrolyzed  chloride,  as c a r b o n  chloride  ZnCl  2  HS  n  H  ->-  chlorosulphanes  Cl-S -CI n+4  are unstable  +  2HC1  and s e n s i t i v e  to  impur-  ities . Chlorination dichloride even  a t room  sulphur 59.5°C to  - SC1 . 2  of sulphur Impure  temperature  chloride (760mm  t h e impure Sulphur  sulphur  with  and c h l o r i n e  Hg) a f t e r  chloride  produces  dichloride  respect  sulphur  i s unstable  to decomposition  b u t i t c a n be d i s t i l l e d  adding  0.5% p h o s p h o r u s  to at  pentachloride  mixture ( 4 2 ) . dichloride  forms  a variety  o f compounds  with  -  14  —""  Lewis The SC1  acids  -  e.g.  suggested  s t r u c t u r e of  temperature (SCl^)  1.322  of  chlorine  produces  which  decompose  i s m i s c i b l e with  above  the  below  in  by  ments  labelled  above  (49)  when 2  and  instability  from  the S  a  culating  molecules  thermodynamic  The  and  range  and  (S ) g  and  H.  of  the  solubility  as  solubility of  experimental essentially  of  Meyer  sulphur (50)  of  were  shown  exchange chloride. (cf. preare  chloride.  Glasstone  consisting  the  have  solution  sulphur  model  sulphur  Experi-  (42)  i s t r e a t e d as predicted  of  sulphur  in  temper-  0°C-119.5°C  amount  species  solution  to  (44).  at  (48)  chlorosulphanes the  low  extensively  i n Appendix  sulphur  sulphur  system  data  -31°C  solubility  significant  that  close  the  ideal  sulphur  shown  of  ideal  solution  treating the  of  the  is sufficiently  justify  is  dissolved  molecules  Also,  of  temperature  is a  s e c t i o n ) suggests  primarily  the  type  tetrachloride  chloride  (radioactive ) sulphur  there  between  the  the  at  sulphur  above  sulphur  point  Aten(47))  100°C  sulphur  However,  H)  the  Solutions  temperature.  chloride  using  Chloride  melting  this  of  diss'ociatively  Sulphur  (determined  2  i s of  dichloride  crystals  Sulphur  sulphur  vious  yellow  sulphur  -  soluble  that  to  Sulphur  atures  S_C1  compounds  -  Addition  of  these  (46).  AlCl^ .  +  in  A1C1 _-SCl„ , F e C l -SC1_ , S b C l - S C l o 2 a 2 D 2  only  (Appendix  values  ideal.  in sulphur used.  of  to In  cal-  chloride The  -  physical phur  properties  are quite  Sulphur  odours  irritants  (51).  sulphur  1.33  energy phide  changes minerals  ( a t 25°C) with  and  chlorine  ides  (without  to oxides)  1.31.  as acute  both  level eight  of exposure hours.  Sulphides  enthalpy  f o r the reactions  have  respiratory  o f Metal.  the calculated  and  o f common  free sul-  chloride.  of Oxidation  oxidation  by Meyer ( 5 0 ) .  dichloride  over  sul-  Chloride  permissible  i s 1 ppm  sulphur  Thermodynamics  discussed  of Chlorination  1 summarizes  Selective  in  vapour  of elemental  o f Sulphur  and s u l p h u r  T h e maximum  Thermodynamics Table  1.34  Properties  and a r e c l a s s i f i e d  chloride  forms  and a r e f u l l y  chloride  revolting  to  of the various  complex  1.32-3 P h y s i o l o g i c a l  15 -  of iron  conversion  i s an i n t e g r a l  of Metal  Chlorides  chlorides  to iron  of non-ferrous  part  metal  o f t h e scheme  oxide chlor-  proposed  -  Table  1:  Enthalpy  and Free  Selected  Metal  16 -  Energy  Sulphides  Values with  Reaction  FeS  !  2  S  FeS  +  CuS  +  s ci  2  PbS  +  s ci  2  ZnS  +  s ci  2  r  2  2  2  +  MoS  +  2  2  2  S  1  s ci 2  T  ft  S  2  -  2  1  2  •  Free reactions  Glassner  -5 2 . 5  -58 .5  -26 . 3  -24 . 4  -  PbCl  2  +  3S  -48 . 9  -47 .0  •>  ZnCl  2  +  3S  -36 . 5  -35 . 0  -38 . 7  -36 . 9  + 0 .7  +  2AgCl  -* •  energy  from  of f e r r i c have  +  +  data  of  c  been  chloride  vapour  Fe Clg  (54)).  7S  Latimer  (52)  and e q u i l i b r i u m  chloride  ferric  3S  MoCl b  values  (Note  2.  4S  -31. 7  3S  (53).  2  +  3  -32 . 7  +  2  a t 700°K  5S  2  +  1  FeCl  +  3  AF°(Kcal)  CuCl  2  C  FeCl  *  -  calculated  Value s  oxygen  C  C  of  S C I  AH°(Kcal)  2  Ag S  f o r Reactions  and other  calculated  that  using  The c a l c u l a t e d  f o r the  chlorides  the data up  predominantly  values  25°C .  constants  metal  at temperatures  consists  at  4. 0  with  of  t o about  900°K  o f the dimer  are presented  i n Table  -  Table  2:  17  -  C a l c u l a t e d Free  Energy  Metal  at  Chlorides  of Oxidation  70Q°K"  Reaction  F  E  2  C  A F°  3  Cg) +  6  1  2  CuCl  2  • 1  PbCl  2  • k °2  ZnCl  2  • k °2  NiCl  2  •  Values  7  ->  °2 -> -«-  °2  ->  -«-  -> -<-  °2  calculated  For  _  F  2  E  the  1  2  PbO  +  C  1  2  ZnO  +  C  1  2  NiO  +  ci  2 ° 3  E  2  of f e r r i c  calculated -5  C  3  C  1  6  1  2  1  2  2  the data  C  C  0 Q  (Kcal)  l°g  1 0  -31  + 9.6  +  - 1 . 55  5  + 28  -8 . 7  +  9  -2. 8  +  3  -0 . 9  of Glassner  chloride,  _  1 0  9.6  °2  set at 0.01 (corresponding  c h l o r i d e i n a continuous  equilibrium P  (at P  to 1%  0 7  '  .  Thus  chlorination  very  little  2  oxygen  will  r e a c t i o n s , and t h e h i g h  be  introduced  P  value C  suppress  oxidation  Experiments  of non-ferrous performed  p r o c e s s ) , the  = 1 atmosphere) i s  2  by  metal  Hohn  1  K  ( 5 3 ) at 700°K,  6  carryover  10  +  is arbitrarily  n I  +  CuO  from  E  F  P  2 °3  6  the r e a c t i o n of f e r r i c  K  If  F  f o r Selected  2  chlorides.  e t a l . ( 9 ) have  into  will  -  qualitatively oxidation fast  at  1.4  of  confirmed ferric  main  under  to  of  were:  to  rates,  the  shown  this  extent  such  the  agent the  be  and  nature  in  reaction  to  the to  be  the Cif  of  be  find  any)  of  the  metal  of  reaction  of  as in  a  sulphur  processing  metals  and  by  rate  chloride specific  sulphur.  data,  and  size  sulphur  on  chemical the  and  objectives  reactivities  on  which  sulphur  reaction  i m p u r i t i e s on  and/or  products  conditions  decomposed  particle  relative  metallurgy.  c o n d i t i o n s under  mineral  origin  used  reaction  Other  effect  geographical  chloride  could  interpret the  seriously  determine  completely  of  been  for extractive  extraction  reactions.  reaction,  effect  never  was  desired to  could  effect  different  reagent study  for  i t was  the  of  has  p r o p e r t i e s o f sulphur  determine  rate  the  of  rate  minerals  composition, and  extent  reaction. The  aim  of  collect  determine  the  process  minerals  products  of  and  chloride  chlorinating  particular,  chloride,  and  a  concentrates  specific  of  as  the  and  sulphide  and  chloride  sulphur  purpose  which  solvent  to  predicted equilibrium  Objectives  investigated  In  the  -  700°K-800°K.  Liquid  The  18  of  this  determination study.  of  reaction  paths  was  not  a  primary  -  2.  MATERIALS  2.1  Materials  2.11  Natural With  a  few  tion  concentrates. are  natural  galena  (MoS ).  The  2  als  are  Natural dustrial would form  frequently  treatment  differ  latter  have  2.12  Synthesis In  chloride  Appendix  minerals  flotation  not  the and  chemical  were the of  course  natural  Minerals  anhydrous  for  methods  annealed  of  analyses  used  in reactivity  of  this  form  which  and  be  described of  have  flotabeen  chalcopyrite molybdenite of  these  miner-  A.  concentrates),  been  to  the  (FeS),  s p h a l e r i t e (ZnS)  and  a p p l i c a t i o n of  involve of  in  in  minerals  pyrrhotite  2  sources  experiments  minerals  natural  (FeS ),  (PbS),  presented  the  sulphide The  pyrite  (CuFeSj),  Minerals  exceptions,  done  -  METHODS  Sulphide  were  studied  on  AND  19  study  ferrous  minerals  from  and  reasons:  developed  and  over  two  natural  in  this  (probably  instudy  in  the  minerals  synthetics  geologic  any  since  time  the  periods  (32).  Chemicals some  chemicals  c h l o r i d e ) and  (sulphur  synthetic  -  minerals  (lead  prepared  i n the  chemical  analyses  The by  sulphide  and  of  these  -  low-sulphur  laboratory.  sulphur  passing  20  The  c h l o r i n e gas  methods  materials  c h l o r i d e used through  in a  chloride mixtures.  distillation  137  (at  the  (.-  distillation  batch.  The  average  material  was  4-7.5  wt  %  chlorine.  1)°C.  composition  weight These  percent  results  theoretical  composition  For  experiments  using  ide  were  weighed  mixed  vestigate  the  intermediate als  with  prepared  by  gas. (vs  The  to  theoretical  found  in  of the  the  lead  in a  lead  of  grade stream 46.0.  46.1  sulphide  sulphide  wt  diffuser  %)  - was  into  of  sulphur  i n good wt  %  was  from  and  of  this  and  52.4  %  chlor-  sulphur. was  iron  used  to  in-  ferrous  of  dried  hydrogen  wt  %  and  53.8  53.9  - used of  prepared  to  wt  miner-  chloride chloride wt %  study  %  CI  CI). the  impurities by  an  was  2  and  be  sulphide  hydrated  absence  CI.  Cl^)  sulphur  (FeCl )  Fe  wt  (S.S  material  %  with  c h l o r i d e might  Fe  by  each  agreement  chloride  (FeCl^)  done  fore-run  S and. 52.6  sulphur  (PbS)  i n the  natural mineral  prepared  was  discarded  r e a c t i o n of  contained  study  several lots  (wt  and  below.  amount  ferrous  This  preparation  discussed  d i s s o l v e the  that  reagent  values  Synthetic reactions  in  400°C  product  of  47.4  chloride  chloride.  heating  2  to  possibility  sulphur  (FeCl .4H 0) 2  ferrous  product  was  sulphur-sulphur  heated  of  Purification  are  q u a n t i t i e s of  and  Anhydrous  of  this  small  temperature)  the  solutions,  A  are  glass  sulphur-sulphur at  p y r r h o t i t e ) were  heating  -  powdered  test  furnace. mixture  The was  minimize product values  pared pyrite  wt S  % in  S  dix  with  86.7  of  wt  wt  %  passing  from (vs  Pb  Pb  low-sulphur  and  and  this  for  13.3  gas  two  values  Other  materials  -  study  listed  are  wt  wt  %  %  in a  the  lead-sulphur  crucible  a n a l y s i s of S  (vs  to  the  theoretical  S).  p y r r h o t i t e (FeS) through  of  muffle  at  a  sample  550°C.  63.5  60.5 wt  %  was  pre-  of  Sullivan  The wt  %  Fe  and  solid  Fe  and  35.7  36.5  wt  %  FeS).  Materials  this  500°C  larger  contained  Other  in  a  The  hours  treatment  theoretical  in  12.9  artifical  at  containing  charge.  hydrogen A)  sulphur  charcoal  the  %  -  crucible  s t o i c h i o m e t r i c , pure  2.13  used  87.0  (Appendix  residue  excess  covered  oxidation  of  by  and  packed  was  A  lead  21  chemicals,  metals,  according  to  and  solvents  -  grade  in  Appen-  sized  by  screening  B.  2.2  Experimental  2.21  Sample  use.  ial.  to  were  After  concentrates  Apparatus  were  P y r r h o t i t e (both  dry-screened minerals  and  Preparation  Mineral before  Methods  minimize  screened sizing,  acetone  and  galena,  i t was  the  air dried. necessary  natural  surface  wet  and  carefully  synthetic)  oxidation.  dry  mineral  and  to  eliminate  samples  To  obtain  to  wash  A l l  were  each  sample  other  fine  washed  reproducible  was  materin  results  with  hot  with  sodium  chloride  solution  leaching. ity  Other  after  2.22  long  -  22  -  (followed  by  water  minerals  p e r i o d s of  showed air  Experimental Apparatus Leaching  schematically lytic  beaker  coated were  experiments  i n Figure  magnetic  stirring  p r o v i d e d by  Temperature ature  71  and  i n the  partially heating  403  done  to  All  a  covered  bar.  the  maintained  i n the  by  an  (Yellow  leaching  to  infrared  pyrex  cc  mixture  by  a  vapour  and  and  a  Teflon  basal  (model  heating  PC  351). temper-  Springs  Instrument  A  indentation  small the  probe  mixture.  lamp  shown  electro-  Thermistemp  to  Co. was  be  Variable  connected  temperature  experiments  chloride  250  allow  reaction  i n the  reactiv-  apparatus  Agitation  beaker  in  i n the  heater-stirrer  probe  relay  sulphur  done  respectively).  immersed  regulator  prevent  and  l i p of  was  was  difference  before  Procedure  reaction  Corning  control  controller  models made  a  and  A  contained the  no  acetone)  exposure.  were  1.  and  via a  voltage  controller.  were  done  in a  from  entering  fume the  hood  to  laboratory  area . For agitation inch  on  reaction  diameter  speed  electric  inserted  300  experiments  g)  at  to  rates,  stainless motor,  test  steel  and  two  opposite sides  For  an  individual  was  brought  to  of  the  effect  stirring  more  violent  done  by  a  1  impeller  mounted  on  a  variable  1/2  inch  radial  the  beaker.  experiment,  temperature  and  was  of  the a  baffles  solvent small  1/4  were  (usually  (usually  1-2  g)  -  F i g u r e 1:  Schematic A. B.  -  23  Diagram  of  the  Experimental  Apparatus  C. D. E.  Heater -magnetic s t i r r e r . Covered 250 cc e l e c t r o l y t i c beaker c o n t a i n i n g the r e a c t i o n m i x t u r e and a s t i r r i n g b a r . Temperature probe. Temperature c o n t r o l l e r , . Power s u p p l y f o r h e a t i n g lamp.  F.  Infrared  heating  lamp.  -  sample had  of solids  was  for fifteen  solvent for  was  then  analysis)  carbon  samples  retained  t h e r e s i d u e washed  weighed.  to  room  and  chloride these  2.3  samples  t o remove washed  and  the f i n a l  wash  glass oven  at  wash  chloride,  the solvent chilled  but  sequence  the residue  chloride sulphur  and water  rinse  water.  a double  elemental  acetone  acetone  i n an  lead  the sulphur  removed  chloride;  briefly  by  and  sintered  required  clean  diluted  to a  product  tetrachloride  disulphide  metal  solutions  solutions.  solution a bent  by  glass  develop  and  monel  alloy  to investigate Solid  a nickel  i n the and  removed  facilitated  any  metal  drying  metal  were  treated  their  reactivities  specimens  plated  with  of  were  sulphur in  suspended  in  test-tube  holder  or  supported  of the i n v e s t i g a t i o n  i t was  necessary  rod.  Analytical In  to  dried  acetone,  with  residues. Iron  on  acetone,  being  i n the beaker  disulphide,  transferred  Galena  carbon  sulphur  chlorides,  the  with  solution  carbon  remaining  the  were  temperature  residue,  carbon  r e s i d u e s were The  and l e t  (selected  80°C,  given.  o f f the hotplate  decanted  rinsed  other  lifted  time  Excess  and  hot s a l t  was  the pre-determined  the s o l i d s .  crucible,  with  When  to settle  the s o l i d s  and  -  seconds  tetrachloride,  Finally,  all  added.  elapsed, the beaker  stand  24  Methods  the course analytical  methods  f o r sulphur  and  chlorine  in  -  sulphur  chloride,  and  -  25  for chlorine  in  low  concentrations  in  sulphur. Chlorine dissolving  a  sodium  off  CS  When  the  sulphur ensure  CS  pH 0.1  7  The  -  was  or  saturated  to  silver  potassium  S C1  sample  of  the  Chlorine  was  sulphur  acidified  this  chloride  barium  sulphate.  to  be  in  a l l cases  of  Ferrous titration  was  2  with  and  in  with  chlorine  Sulphate  was  filtered,  or  chlorine  %S  +  total  %C1  elements iron  repeated  by  NaOAc  were  to  at  titrated a  drop  with  of  dissolving saturated  aqueous  during  a CCl^  and  hydroxide.  complete  ignited,  were  the  aqueous  conversion solution  precipitated  values  and  totalled  was  with weighed  analysis  was  100  as  found  -  0.4%  determined.  determinations  cerium(IV)  compounds.  the  sodium  resulting  boil  indicator.  by  ensure  to  filtered,  using  as  dilute  to  The  both  standard  aliquots  determined  i n excess  since  into  by  adding  2  was  buffered  solution  CS ,  heating  was  cycle  solutions  unknown  sulphur  where  and  in  S-Cl  mixture  -  determined  and  of  chloride  nitrate  solution,  negligible  of  volume  boiled.  barium  was  unknown  The  solution  sulphate.  and  the  washed.  solution  added  to  Loss  2  the  hydrolysis  chromate  in  hydrolyzing  the  extraction  Sulphur weighed  of  and  diluted N  of  sulphur  CNaOAc) s o l u t i o n  resulting  0.001  in  evaporated,  up  complete  and  2  sample  hasten  had  2  broken  phase.  2  acetate  and  2  S> C1  weighed  aqueous the  in  sulphate  were  done  solution  by  using  -  (1,10)-o-phenanthroline iron  for total  sample  with  iron  test  26  -  indicator.  determination  lead  In  Reduction was  done  hydrochloric  acid  by  of  ferric  boiling  solution.  the  -  3.  RESULTS  AND  3.1  Decomposition Sulphur  3.11  distilled C-l)  DISCUSSION of Pyrite  and R e l a t e d  of Pyrite  with  Sulphur  Compounds  by  Chloride  s t o i c h i o m e t r y of the r e a c t i o n sulphur  chloride  was  of p y r i t e  determined  (See  with  Appendix  t o be:  2FeS. 2  However,  occurs be  +  3S.C1 2  as shown  uniformly  to  -  Chloride  Reaction The  27  0  2  -*  i n Figure  to completion.  ( i n a constant dependent  temperatures  up  2FeCl  on  2, The  weight  the size  +  3  this  10S  reaction  extent  to which  of sulphur  point  n o t go  the  reaction  c h l o r i d e ) was  of the i n i t i a l  to the b o i l i n g  does  pyrite  o f pure  found  sample  at  sulphur  chlor-  chloride  on t h e  ide . A mineral plete-'  protective surface  was  reaction.  layer  of product  suspected  The p r e s e n c e  t o be  ferric  the cause  of anhydrous  of the  ferric  incom-  chloride  fa (added was  as r e a g e n t  found  o r as t h e p r o d u c t  to decrease  the extent  of a previous  of reaction.  reaction)  The  results  - 28 -  TIME (MINUTES) F i g u r e 2:  Reaction  of P y r i t e w i t h Pure Sulphur C h l o r i d e a t 133°C.  (a)  1 g FeS  2  i n 300 g  S C1  2  (b)  2 g FeS  2  i n 300 g  S Cl  2  2  2  -  of  these  extent  of reaction  initial pure  experiments  reaction  sulphur  visually  vent  sulphide  the  was  less  present  than  chloride  i n the  that  film  of massive  i n sulphur  with  could  polished  chloride  since  layer  left  of a protective  layer  of  reaction found,  iron  (II) chloride The  chloride  reaction  I t was  could  be  be  pyrite  any a  sol-  clean  by  the b o i l i n g  i n sulphur  with  sulphide of  amount  with  of  amount  the mineral  of p y r i t e  ferrous  associated  substantial  iron of  surface.  i n pure  sulphur  to the reactions  to find  of  conditions  under  decomposed, the r e a c t i o n  addition The  reactor.  the  t h e amount  material  no  ferrous  other  3.162.  the temperature  pressurized  on  significant  in relation  desired  reactant.  extending  reaction  completely  changed  to raise  No  i s associated  i n Section  Since  chloride  soluble  i n d i c a t i n g that  incomplete  were  intermediate)  determining  residue.  i s discussed  materials  by  (dilute) acid  was  sulphur  ferric  was  but the  liquid  investigated  (II)  was  always  the adhering  Ca p o s s i b l e  solid  tions  chloride  the surface  possibility  i n the  pyrite  was  non-reproducible,  surface.  chloride  iron  quite  No  reaction  removed  The  surface  on  -  ferric  chloride.  after  which  when  mixture  detected  specimens  were  29  of sulphur  original point range  However,  chloride  was  purpose  to the  available  found  t o have  addition  mixture,  without  the presence  condi-  sulphur  of this  of the r e a c t i o n  which  of  using  thus a  dissolved  a strong  effect  -  on  the reaction  temperatures  of sulphur  investigated  cussed  below.  3.12  Reaction  30  -  chloride  with  pyrite  CllQ-150°C).  of Pyrite  with  This  at  a l l  effect  Sulphur-Sulphur  is  dis-  Chloride  Solutions 3.121  Effect The  ide  was  of Dissolved  extent  found  dissolved  to which  t o be  sulphur  i n the sulphur  CFigure  3) showed  sulphur  content  of sulphur  ide  C25  and wt  reaction of  2  3,  the  range  the  reaction  are  25-40  2  and  uniformly  goes wt  reacts with  wt  increasing  40  wt  %  there  not s i g n i f i c a n t l y  2  the rate  2  affected  by  and  chlor-  solutions, From  the  sulphur  and t h a t  complete  % sulphur  is a critical  of dissolved  to completion, 2  2  of  dissolved  t o more  wt  S.S C1  chlor-  Experimental the  leads  % sulphur-75  sulphur  the presence  chloride.  chloride  that  %)  % S.S C1  by  to completion.  i t appears  o f 10-25  that  i n 25 wt  % S.S C1 )  goes  Figure  range  that  pyrite  strongly affected  results  reaction  Sulphur  results level (in  above  i n the  extent  which  composition  of the  t h e amount  of  the  reaction  dissolved  sulphur. The pyrite  solvent  composition  decomposition  was  found  to react  has  a higher  ing  the temperature  atmospheric),  was  40  wt  uniformly  boiling  point range  and has a  chosen  % S.S C1 , 2  2  i n which  to completion.  than  25 wt  available  lower  for further  vapour  %  This  S.S C1  without  2  2  work  pyrite solution  (thus  pressure  pressure  than  on  extendabove  pure  -  10  i  -  3 1  20 TIME  F i g u r e 3: Effect  30  40  (MINUTES)  o f D i s s o l v e d Sulphur on the R e a c t i o n of P y r i t e  Sulphur C h l o r i d e t 1 3 3 ° C C S u b s t r a t e ; (a) 1 g F e S i n 300 g S C 1 a  2  2  2  (b)  1 g FeS  2  i n 300 g 10 wt % S . S C 1  (c)  1 g FeS  2  i n 300  2  -70 Sul+ l i v10Q an  2  25 o r 40 wt % S . S C l 2  2  with mFees S h. ) 2  - 32 -  sulphur  chloride.  sulphur  chloride  of  dissolved  amount For  pyrite  3.122  Effect  by  with  shown  i n Figure  of  i n 40  wt  speed  once  effect was  violent  m o d i f i e d by  same  speed  limiting  requirement reach  this  3.123  (.Figure  on  f o r complete  the chlorine  con-  con-  Rate  the rate  independent  of b a f f l e s  To  results  and  of  reaction stirrer  test  the  of Figure  t h e use  (Figure  stirring  i n the  of the  the apparatus  suspension  of a  4 ) show  and  the  t h e same  of the p a r t i c l e s  to  rate.  Microscopic  examination  Indicated equiaxed,  the  i n the  of s t i r r i n g  that  magnetic  Model  (.roughly)  sulphur.  experiments,  i n suspension.  A Geometric  8)  rates  was  The  as w i t h  limiting  changed  agitation,  impeller.  the  is essentially  the Reaction  the i n s e r t i o n  rate  i n these  1 showed  were  level  to minimize product  of  than 1 % .  S . S 2 C I 2  a l ls o l i d s  o f more  variable  %  a high  of the substrate  various  apparatus pyrite  used  used  less  of S t i r r i n g  Experiments  desirable  reaction  application  of sulphides,  of the solvent  g) o f s o l v e n t  of the solvent  industrial  to c r y s t a l l i z e  samples  CS:C1 ratio)  (3QQ  be  necessary  s i n c e .complete  quantity tent  decomposition  of cooling  composition  i n an  s u l p h u r would  the small  stant  Also,  of the Reaction  that and  of the p y r i t e  the i n d i v i d u a l  the form  concentrate  particles  of the p l o t  were  of percent  1  -  2  33  -  20  O < LLI  tr.  Ul  o  tr UJ o.  1 2  3  4  STIRRER SPEED  g O < UJ  tr  o cr ui  GL  0  100  200  300  IMPELLER SPEED Figure  4:  The E f f e c t o f S t i r r i n g on the Rate of R e a c t i o n of FeS,, w i t h 40 wt. % S.S C1 2  2  ( " S t i r r e r Speed" r e f e r s t o c o n t r o l d i a l  A. A g i t a t i o n by Magnetic S t i r r i n g P e l l e t . at S t i r r e r Speed = 1. B. A g i t a t i o n by I m p e l l e r w i t h B a f f l e s . at I m p e l l e r Speed = 100 rpm. Conditions:  (RPM)  T  - 126.2°C,  Reaction  time  A l l Solids  A l l Solids  minutes  in  a l l  cases  Suspended  Suspended  s u b s t r a t e : - 7 0 + 100 m S u l l i v a n = 10  setting.)  FeS  2  -  reaction rate  v s . time  of decomposition  equation when  describing  the i n t e r f a c e  constant  c a n be  3  o  where  r  velocity  the p a r t i c l e reacts  of  surface  =  dt  if  a  constant  of the p a r t i c l e s .  o f an e q u i a x e d  An  particle  surfaces  is  follows: equiaxed radius  at a rate  p a r t i c l e having and a i s a  which  a volume  constant,  i s constant  per  unit  t is R  then  then  k  the f r a c t i o n  area)  with  of the reacting  as  a roughly  area,  consistent  the r e a c t i o n  If  —TT  t o be  i s the i n i t i a l  o  -  (per unit  derived  Consider ar  appeared  34  or  r  = r  o  - kt  of the p a r t i c l e reacted  a t time  3 r-kt, v-t-q = t f r a c t i o n unreacted) = i £ — = (-2 = (1 - iH) 3 r r ar o o o  Cl-R)  therefore  C l - R )  1  7  3  =  1 -  —  r  or  r  o  o  [ 1 - ( 1 - R )  1  /  3  ]  =  kt.  ^ 1/3  If linear, per  this  this  unit  single  a plot  of the function  indicates  of surface  that  area.  p a r t i c l e or a group  case  i t i s used  r  ] v s . time i s  [1-(.1-R)  the reaction  rate  The  c a n be u s e d  function  of equally  f o r a group  sized  of narrowly  ( b e t w e e n two s c r e e n sizes). Values of r were c a l c u l a t e d o  f o r each  i s constant for a  particles. sized  screen  In  particles  size  d  -  fraction.  For a p a r t i c u l a r  calculated  by  The r  o  ] vs t .  geometric  3.124  screen of  1/3  of the screen  of S u l l i v a n  and  were  C55)  values  Samples  reacted  vs time  varies  by  o  were  Sullivan  %  i n the  form  calculated  from  (Appendix  A)  D-4)  of various  over  S . S 2 C I 2  Representative  f o r these  Q  Pyrite  (Appendix  wt  of r  < 4%.  plotted  of r  pyrite i n 40  the value  dimensions.  on  temperatures.  reaction  Figure  The  of Experiments  sizes  fraction,  d a t a were t h e n  Results  times  cent  mean  -  size  s e v e r a l methods  experimental  [1-Cl-R)  the  35  a  plots  range  of  r e a c t i o n s a r e shown  per-  in  5 . The  experimental  d a t a were t h e n  plotted  i n the  form  1/3 r^Cl-d-R) sample with  tion acted for  of such  40  range  ] vs t i m e .  wt  %  Since  i t i s t o be  the smallest completely.  6 shows  f o r the reaction  S . S 2 C I 2 .  of sizes,  of Sullivan  the s t a r t i n g  expected  of the o r i g i n a l This  a representative  effect  that  m a t e r i a l had after  particles  i s shown  pyrite  will  65  %  a  reac-  have r e -  i n Figure  5  (plot  129°C). No  rates will  attempt  calculated be  subject  absolute  terms  was from  made  t o compute  the slopes  t o some  pf r  correction  a shape o  factor, 1/3 [l-(l-R) ] vs  factor  t o be  so the time  accurate  in  terms.  Table in  plots  Figure  3 summarizes  of the c a l c u l a t e d  the r e s u l t s  of these  interface  velocities  experiments (rates  of  -  36  -  TIME (MINUTES) Figure  5:  R e a c t i o n o f -200 + 270 m S u l l i v a n FeS  w i t h 40 wt. % S.S CI  -  37  -  TIME (MINUTES) Figure  6:  Plot of  of r  -200  o  [l-(l-R)  + 270  m  1/3  ] vs  Sullivan  Time FeS  2  f o r the i n 40 wt  Reaction %  S.S C1 2  Table  3:  of  Sullivan  Reaction  40  %  S.S 2^ 2  wt  (  x  of  r  e  penetration  -70  +  a  c  T  l  o  of  the  (cm  -270  rate  T(°C  2 . 01  113 . 0  1. 29  120.0  3  119 . 7  1.86  126.2  5.38 129 . 0  4 . 49  133.0  x  +  10 )) 5  325  )  m  rate  2 . 15  119 . 9  8.70  139 . 7  12 . 6  146 . 9  19 . 2  variations  as  mm  270m  +  113.0  .14  with  expressed  solid  T ( °C )  rate  Pyrite  rates  n  -200  100m  T (°C )*  the  -  of  Screen Size Fract ions  of  38  Rates  rate  Small  -  in  temperature  139 . 7  measured  10 . 2  temperatures  controller  over  the  are  due  period  to  of  drift  experi-  mentation.  penetration)  for  three  pyrite  concentrate.  slopes  of  plots  It various to  These  size  rates  the  form  of  is  suggested  that  the  size  fractions  at  different  tributions corrosion  of  screen  shape  within (Figure  factors the 7)  the or  screen which  fractions were  Figure  Sullivan  from  the  6. rates  for  temperature  different fractions,  exposes  the  calculated  different  same  of  more  may  particle or  to  area  the be  size  due dis-  crevice to  attack  and  -  39  -  Absorbed E l e c t r o n Image Micrographs, 240 x M a g n i f i c a t i o n .  -  may  occur  addition  to a greater i t may  individual that the  Sullivan  samples  i n 40 wt  evidence  mesh  fraction,  one g r a i n ,  surface Figure  a n d -200  In  and  area,  causing  8 shows  + 270  mesh  Point  A sample  trations have  with  fresh  was  ores  40 wt  leach-  pits  or  the s i z e  of  faceting  The  + 100  extent  solvent,  or  other  .  a n y o f t h e common  catalyze  % S.S2CI2  mesh  containing  Sullivan  mixture  of r e a c t i o n that  the rate  inhibit  a  a  large  i n 40 wt  pyrite  %  was  and t r e a t e d f o r ( 2 2 % ) was t h e  a t low  of the impurities on  or  solutions,  chlorinated  indicating  none  % S.S.C1  that  might  completely  a significant effect  with  etch  material,  concentrate  the r e a c t i o n  i n the solvent  amounts of  Although  without  40 wt  galena  at 133°C.  as w i t h  various  the p o s s i b i l i t y  o f -70  into  after  dissolution.  i n sulphide  of Impurities  introduced  pyrite  more  solutions.  of pyrite  of Pine  10 m i n u t e s  ture  than  rates.  decreases  Investigate  S.S2CI2.  same  more  i n the leached  particles  reaction  variety  then  % S.S^Cl^  impurities  sample  + 100  particles.  i n the coarser  exposes  7 shows p y r i t e  of anisotropic  To  the  that  reaction  o f -70  are evident  leached  trace  i n the coarser  pyrite.  channels the  -  contain  attack  calculated  Figure ing  be p o s s i b l e  intergranular  unleached  extent  p a r t i c l e s may  higher  40  concen-  in this  of reaction  mixof  -  Figure 8  :  41  Absorbed E l e c t r o n Image M i c r o g r a p h s , M a g n i f i c a t i o n = 240 x A  -70 + 100 m S u l l i v a n F e S  B  -200 + 270 m S u l l i v a n FeS„.  2  -  To initial  investigate  ratio  reaction, 40  g  of  a  -70  S.S2CI2. added  for  5 minutes  200  over of  at  allowed  posed.  The  The  rates  Sullivan pyrite  an  Arrhenius  smaller  The tion  plot  energy This  stirring  at  of  clear  and  was  done  g  and  pyrite  to  of  was  residue  magnetite  0  held  solid liquid  of  was  the decom-  consisted  (Fe  %  was  then  Analysis pyrite  wt  boiling  supernatant  the  with  25  avoid  the  the  total  500  and  analyzed. of  the  mixture  100°C,  of  ) content  the of  C-3).  40  wt  of %  the  -70  +  S.S2CI2  9).  This  p a r t i c l e s are  nearly  21.7  100  were  size  mesh f r a c t i o n used  to  construct  f r a c t i o n was  completely  reacted  used in  temperatures. the  Arrhenius.plot  -  Kcal/mole.  2  a c t i v a t i o n energy  (.beyond  minutes  insoluble  reaction  (Figure  of  and  130°C  The  99%  on  in  Energy  with  high  slope  5  to  Appendix  Activation  to  The  that  water  The  times  cooled  residue  (see  of  of  variation  experiment  reaction.  CZnS),silica  of  heated  period  showed  solid,  concentrate  because  large  solution  scale  settle.  the  products  short  a  the  to  and  sulphide  was  150°C,  reaction  3.125  mesh  solvent  heat  decanted  the  S.S^Cl^  a  Sullivan pyrite  to  zinc  to  of  +  gradually  products  effect  large  The  the  pyrite  -  relatively  due  was  of  the  42  that  value,  necessary  to  indicates  the  lack  suspend  the  of  an  activa-  effect  of  particles in  -  43  -  TfC)  146 9 1397  -3-6 £ E  1330  1262  120 0  250  255  1130  -3-8  ill -4-0h < cr  ?  g  -4-2 h  O < LU -4*4 h  rr  o  Q  -4-6 -4*8  2-35  2-40  245  2-60  '° /T°K 3  Figure  9:  Arrhenius Sullivan  Plot Pyrite  for  the  with  40  Reaction wt  %  of  S.S C1 2  -7Q 2  t  100 m  -  the  S.S^Cl^  solution)  on  44  the  -  reaction  rate,  and  the  linear-  1/3 ity  of  rate  the  plots  limiting  of  r  factor  [l-(l-R) is  a  ] vs  chemical  time  phase  indicate  boundary  that  the  reaction  (56). 3.126  Reaction Pyrite  were to  reacted  compare  livan were  Pyrite  samples under  the  The  of  Noranda  p y r i t e , but linear  in  from  the  rates  from  both  Mines  conditions  Source  Ltd.  as  (Appendix  Sullivan  A)  material  reaction.  pyrite with  Different  Noranda  same  of  a  reacts ^50%  the  cases  same when  slower  than  stoichiometry. plotted  in  the The  the  Sulresults  form  1/3 r  [l-(l-R)  of  -70  +  ing. are  appears  relatively for  ence  in the  3.13  time  100.mesh  It  area  for  ] vs  surface  and  that  surfaces  —  thus  attack.  It  difference  in  of  reactions synthetic  and  40  S.S C1  stoichiometry found  2  of  (.Appendix  2  the C-4)  is  at  and  Synthetic  be:  less  the  studied.  samples  before  Noranda  leach-  material  effective  that  two  this  differ-  responsible materials.  Pyrrhotite  (Sullivan — with  shows  partially  between  limited reaction to  the  suggested  least  natural  been  of  11  pyrites  presenting  pyrrhotite  have  Figure  Noranda  reactivity  of  sulphur %  is  Natural  low  wt  the  roughness  Reaction  10).  Sullivan  smoother  chemical  The  (Figure  Appendix  (initially) The which  A)  pure  S C1 2  observed occurred  and  was  -  45  -  Noranda P y r i t e s Reacted w i t h 40 wt.  % S.S  CI  at  119.9°C.  -  46 -  A  B  11: -70 + 100 m S u l l i v a n and Noranda P y r i t e s B e f o r e L e a c h i n g . A, B Kimberley F e S ; 2  A,C,D Absorbed B  C,D Noranda  FeS  2  E l e c t r o n Image M i c r o g r a p h s , 240 x  B a c k s c a t t e r e d E l e c t r o n Image M i c r o g r a p h , 240 x.  _  2FeS  The sample  reaction  size  pyrite,  a r e shown  In c o n t r a s t  results  Formation chloride  not  be  removed  adhering  ferric  chloride  determined. on  (II)  partial  with  increased by  some  of experiments ( 4 0 wt  %)  on  of  sulphur  significant effect  on t h e  of f e r r i c  to the  found  chloride  the extent  t o be  surface  of  the case  reaction  with  film  from  reaction  but  a  pyrite,  or  a film  as  which also  ( i fany) t o which  the r e a c t i n g a film  product  surface  surface  were  could  of f e r r o u s  of water  could  carbon  o r dichloroethane  titration  ferric  probable  such  such  the mineral  to detect by  t o be  Solvents  so the e x t e n t on  of ferrous  seemed  disulphide,  surface  i n the s o l i d  after  is stifled  of the r e a c t i o n ,  Attempts  the r e a c t i n g  rate  inhibiting film  solvent  a  with  reproducible.  chloride,  formed  pyrrhotite  and  12.  amount  positively identified. carbon  composition,  of reaction  depressed  at the sulphide  tetrachloride,  moved  no  Addition  o f an  of the s t i f l i n g  extent  large  b u t , a s was not  of Sullivan  in reaction  had  mixture  were  solvent  to the r e s u l t s  solution  8S  the r e a c t i o n  of a  of reaction.  pyrrhotite  cause  that  +  i n Figure  decrease  indicate  reaction  2FeCl  of temperature,  the presence  initial  the  •>  the decreased  the i n i t i a l  extent  C1  the r e a c t i o n  abrupt  and  product.  of  on  chloride The  sample  3S  effects  size  sulphur  in  +  i+7 -  ferric  n o t be chloride  soluble  complicated  re-  iron  by t h e  - 4 8  90  o40%SS CI 2  I33°C.  2  80 L / 70 60 r o ^ iu <  /  -• 4 0 % S S C L  A  2  I33°C  2  50  U J  40  40%S S CI II3°C 0  2  UJ  o cr  UJ Q_  4  0  2  30 20  -o S CI II3°C 2  10\- cr  0 Figure  12:  10  2  12•  50  20 30 40 TIME (MINUTES)  R e a c t i o n o f -140 + 200 m S u l l i v a n FeS S•S  o 2g.FeS • 4g.FeS  with S C 1 2  2  and 40 wt. %  60  -  tendency wash (wash  solution.  High  solution  passed  tained, rous  of the sulphide  but there  chloride To  on  film  on  investigate  the r e a c t i o n  pyrrhotite  was  experimental material  was  and  49  to dissolve erratic  through no  appears  temperature,  e.g. 113°C,  with  wt  than  These the  role  2  wt  2  results  of dissolved  with  was  S C1 2  are d i f f i c u l t sulphur  composition  as  2  4. the  reaction  found  fer-  synthetic 2  of rapid  ob-  material.  % S.S C1 .  way  blanks  substantial  i n Table  i n t h e same  ticular  S.S C1  40  acid  were  of the mineral  are summarized  except  %  o f any  low s u l p h u r  mineral  40  solids)  of leached  with  the extent  slightly  ClI) titration  unleached  the e f f e c t  to react  that  iron  the surface  treated  results  in a  indication  of p y r r h o t i t e , also  -  t o be  The This natural at a  par-  greater  2 >  to explain  i n the  solvent.  i n terms  of  -  Table  4:  Reaction  50  -  of Synthetic  FeS and F e C l  2  with  S.S C1 2  Solutions  Solvent  40  wt  s ci 2  Substrate  % s. s c i 2  (2  FeS  2  Time minutes  T°C  % Reaction  mg Fe reacted  5  113 . 0  47  284  g)  II  II  10  II  50  302  II  n  20  II  52  314.  113 . 0  28  169  FeS  2  g)  (2  5  II  it  10  II  30  181  II  II  20 '  it  32 .5  193  5  113 . 0  s ci 2  FeS  2  g)  (1 it  II  40 wt  % s. s c i 2  FeCl  2  s ci 2  2 it  II  FeCl  2  2  (1  5  g)  (3  g)  5  (1  g)  5  II  II  In  300  3.14  g of  II  10  90  32  95 395  95 . 3  113 . 0 II  88  113 . 0 II  60  30  1241  80 .5  358  78. 7  350  solvent.  Reaction  o f Anhydrous  Ferrous  Chloride  with  Sulphur  Chloride As is  has been  mentioned  previously,  considered  t o be  a plausible  reaction  of iron  sulphides  the test  the s t a b i l i t y  which  sulphides  under  nitrogen  of ferrous  react, t o pass  samples a  ferrous  intermediate with  sulphur  chloride of this  70 mesh  in chloride.  under  were  To  conditions  material  screen)  chloride  in  (broken  treated  with  -  S C1 2  and  2  varied  40  were  oven  drying  results  ferric  with  2  from  % S.S C1 ,  nearly  completely  3.15  Reactions The  and  was  gated. that  This  was  plete  understanding  Also,  large  was of  flat  expected surface  that  films  Strips 40  wt  more the  %  complex  than  experiments It  was  The that  films iron  the  amount In  rapidly  Sulphur  Chloride  with  sulphur  were  might  also the  lead  and  would  chloride investi-  possibility  t o a more  of iron  readily  com-  sulphides.  available,  simplify  and i t  the  detection  existed. were  behaviour  treated  of iron  of the i r o n  that  form  (II) converted  conditions.  to explore  were  a r e summarized  observed  to  converted  solutions  surfaces  i f such  .  iron  of the r e a c t i o n s  such  partially  of iron  with  reactions  of metallic  S.Sg-Cl  was  Iron  i n order  specimens  experimental  chloride.  chloride  knowledge of these  reacted  t h e same  of metallic  done  and  4.  chloride  of M e t a l l i c  sulphur-sulphur  The  was  resi-  of water,  d i f f e r e n t from  under  to f e r r i c  reactions  omitted.  procedure  reaction  instead  t h e amount  quite  ferrous  2  the s o l i d  chloride  pyrrhotite  2  was  However,  chloride  experimental  tests:  i n Table  ferrous  2  chloride.  reacting  The  of the residue  S C1 ,  -  d i e t h y l ether  are summarized  ferric  wt  S.S^^.  f o r these  washed  In  40  %  slightly  dues  to  wt  51  in this  sulphides.  i n Figure  a film  with  formed  S C1 2  2  and  system i s Results  of  13. on  the surface  of  -  52  -  \/ T I M E 0  CM  .  60o[  2 ll_  6  8  10  r  T  • MG. vs. T I M E  2i  o MG. vs. N/TIME  o ro  4  Q  o  500 400  0  20  40 TIME  F i g u r e 13:  Reaction  60  80  100  (MINUTES)  of Fe w i t h 40 wt. % S . S C 1 2  2  (a) and S C 1 2  2  (b) a t 133°C.  -  iron or  treated  water  was  dissolved i t was  The  film  the  entire  film  grew  film  formed  chloride.  reaction  and/or  by  film  until  When  smell was  was  iron  i t appeared The  the  growth  film  noted, sulphide.  to  cover  of  this  14. with  i n water  40 wt  reacted chloride  This  2  film  The  (Figure  gradually  a barrier  S.S C1 ,  a  2  was  form 13)  pale  insoluble  determined  C-5)  v s . time film  %  a n d was  (See Appendix  forming  acid.  i n acetone  t o be  of the p l o t  indicates  thickens  and  to d i f f u s i o n of  slows  reactants  products. Figure  Ct)  plots  the surface form  insoluble  sulphide  the surface.  but soluble  the ferrous  in dilute  treated  on  of iron  was  of the specimen.  was  weight  vs.  that  When  iron  film  a hydrogen  i n Figure  ferrous  the  soluble  i n a streaky  surface  -  The  2 <  in acid,  concluded  acetone  that  2  i s shown  green  of  S C1  but r e a d i l y  so  in  with  53  '  13  also  for iron  shows  in S C1 2  are approximately  evidence  that  film  3.16  Summary  and  3.161  Summary  of  It ferrous  was  and  2  linear,  formation  of weight 40  wt  thus  affects  Discussion  of iron  % S.S C1 . 2  the rate  of Experiments  These  2  providing  reacted  additional of  on  reaction.  Iron  Compounds  Observations  observed  chloride  plots  that  a l l behave  reactions  with  sulphur  reactions  i n these  iron,  somewhat  chloride.  systems  the i r o n  differently  The  are l i s t e d  sulphides,  possible i n Table  in  and their  chemical 5 with  some  -  F i g u r e 14:  54  -  Growth of FeS F i l m on I r o n R e a c t i n g w i t h a  before r e a c t i o n  b  t = 5 minutes  c  t = 10 minutes  d  t = 20 minutes  S2CI  -  appropriate extended  Table  observations.  time  5:  55 -  reaction  Reactions  Table  6 shows  rates  f o r these  of FeS ,  FeS, F e C l  2  the i n i t i a l  systems.  a n d Fe w i t h  2  Reaction  1) F e S  3)  + S C1 2  + j  2  S  ->  2  C  1  2  FeCl '+  4S  2  2  F  e  C  1  3  +  S  2  +  |  FeCl but  was  2  2  2  not observed  i s a possible  tion  = 1) + 2) FeS  S C1  Observations  2  2) F e C l  and  intermediate  Observed  S C1 2  FeCl  2  + 5S  3  The  stoichiometry.  reaction  plete  2  5) F e S + |  S  C  FeCl  2  1  2  2  F  e  C  1  + 3S  2  3  +  4  FeCl  The is  the solvent  >10  w t . % S.  was n o t o b s e r v e d ,  2  Observed  S  i s incom-  unless  contains 4 ) F e S +' S C 1  reac-  stoichiometry,  extent  of reaction  dependent  on  sample  size. 6 ) Fe + n S . S C l 2  2  -»- F e C l  (n+2)S  2  An  FeCl  formed 7) Fe + j  S C1 2  2  -»•  FeClg  + 3S  FeClg uct  )  4Fe + j  S  C 2  1  2  3  F  e  S  +  ;  F  e  C  1  3  2  + ±  S C1 2  2  FeClg  + S  was  s.s ci  i n 40 wt  2  i s the f i n a l  of S C1 2  FeS f i l m  was  in  reaction  with  o n Fe  observed (initial  100% S C 1 . 2  Fast 2  Fast  0  ally  complete  s.s ci 2  2  but incomplete i n  S C1 .  2  2  prod- .  attack  2  An  ly) 9) F e C l  layer  2  and  virtu-  i n 40 wt %  -  Table  6:  Initial  FeS,  Substrate  FeCl  2  56  -  and E x t e n d e d and  T°C  Fe  Time  in S C1 2  Solvent  Reaction  and  2  40 wt  Rates %  f o r FeS  S.S C1 . 2  2  I n i t i a l rate Rate after / -2 . - 1 , e x t e n d e d t i m e Cg cm mm ) _ ( g cm min ) 2  FeS  s ci  113  2  ti  2  133  FeS  40  2  2  40  %  wt  4  4. 2 X  10  ^2.1  X  lO'  4  <1 X  10  6 X  lO"  4  1 X  10  X  lO"  4  5 .1 X  lO"  4  2  2  s ci  113 . 5  113 . 5 40  It  was  pyrrhotite fast  observed  and  but that  ferrous these  i s complete  reaction  was  found  thermodynamic  that the film  be  substrate of f e r r i c  2  that  the i n i t i a l with  decrease  (Table  t o be  6).  dependent predict  reaction  10  1 X  10  of  on  sample  size.  surface  is effectively amount  -6 -4  ferric  i t may  be  by  of f e r r i c  the  fast Since  chloride supposed  continues  covered  are  before  of the  reaction  -5  pyrite,  chloride  extent  the fast  The  reactions  The  product,  -5  fast  sulphur  that  -4  known)  considerably  systems  chloride.  X  -5  0.1 X not  very  2  chloride  calculations  the f i n a l  i n these  s.s ci  rates  reaction  should  %  wt  8.5  X  2  (area  ft  10  lO"  1.7 2  <1 X  X  2  s.s ci  ICT*  4.2  2  2  s.s ci  s ci  133  FeCl.  %  wt  133  it  2  2  113 . 5 40  Fe  s.s ci  s ci  113 . 5  II  %  wt  > 8 X  2  an  only  until  inhibiting  chloride  -  required tion the  to s t i f l e  o f the form case  iron  the fast  was  equivalent  3.162  The R e a c t i o n  initially  pure  of  chloride  pletion 25-40  when  wt  sulphur  the case  reaction  reacting  surface  reaction  1 plus  high  sulphide  2  that  chloride  of pyrite (.Table  to depress below  by t h e m o t i o n  on  the surface.  observed leached  uniformly  reacting  i n 25-40  the level  solid)  the r e a c t i n g  with  by t h e p r e s e n c e  chloride  chloride  chloride. surface  level  t o com-  containing  produced away  activity  from  from  sulphur  at the of  ferric  sulphide  the surface before  chloride  (as a conver-  formed  a protective i n this  nickel-iron  carbonate  at the  of sulphur  at the  not form  when  %  of dissolved  interpretable  system  i n ammonia-ammonium  suppressed  of the l i q u i d  would  wt  of decomposition  Any f e r r i c  An e f f e c t  i n an a q u e o u s  be  the chlorine  be t r a n s p o r t e d  from  reaction  of pyrite  sulphur  initial  then  to ferric  reacts  concentration  surface  sion  i s inhibited  5) w o u l d  Ferrous  suspended  of  sulphur.  chloride. may  a film  and t h e  the reaction  pyrite  to excess  the high  surface  chloride,  In  pyrrhotite.  i f the l o c a l  enough  func-  Pyrite  but that  exposed  S . S 2 C I 2 J  of  t o be a  of the substrate.  on t h e s u r f a c e  observed  % dissolved  For  were  of  appears  i n sulphur  to that  has been  ferric  iron  formed  became  It  reaction  and c o m p o s i t i o n  of metallic  sulphide  57 -  solution  away layer  way i s  alloy i s (57).  At a  -  high  solution  iron(HI) ferric of  at  tion but  or  oxide  pyrite  which  an  i t is  pyrite  ide  point  chloride because thus  tion  this  that  the  in  of  wt  and  this to  the  which  the  is  hypothesis reaction  rate  is  does  is  indica-  insoluble  in  the  the  case  soluble, as  surface. finely  for  no  a to  ferric  be  by  the  adhere  to  hydrous  In  formed  not  to of  is  would  possible is  product  sulphide  recrystallizing which  layer  there  chlorinated  system be  a  reaction.  chloride  is  oxidized  forms  chloride  solid  is  S.S2CI25  %  ferrous  from  believed  mechanism  However,  that  surface,  produced i t is  40  iron  and  stops  ferrous  remote  incapable  tation  with  or  suspended  reacting a  surface  slows  possible  -  potential,  the  initial  divided  at  near  reacting  that  finely  oxidizing  58  the  chlor-  Ferrous divided  solvent  and  solution-precipi-  ferric  not  consistent  is  independent  chloride.  with of  the  the  observastirring  speed. The 4Q  wt  %  S.S2CI2  diffusion no  observed are  through  a  kinetics also  3.163  The  Reaction  The  failure  measurable  rates  presumed  to  be  chloride  product  in  due  of of  of  which  film  such  a  of  reaction with  rate  constant  film  was  of  pyrite  with  control  by  thickness,  but  found.  Pyrrhotite pyrrhotite  S2CI2 to  the  consistent  surface  a n a l y t i c a l evidence  of  and  40  suppression is  formed  to  react  wt  %  of or  completely  S.SjC^ the  solution  reaction  deposited  at  on  by the  is  ferric sulphide  -  surface. of  There  ferric  chloride  deposited tion  is  3.164  from  The  film  of  40  wt  %  a  finely also  thin  chloride  an  as  a  on  formed  may  stable  in  may  is  a  under  formed  the  a  surface.  very  S.S2CI2,  %  reac-  local the  i t  is from  which  but  iron an  the be  a  It  of  through  of  surface.  extremely  iron  and  continuously the  ferrous at  inhibiting In  S2CI2,  presumably  chloride  is sul-  concentration  formation  ferric  with  growing in  would  This  observa-  rapidly  between  i t is  the  layer  sulphur  iron)  surface.  S.S2CI2,  film  %  reactive.  diffusing  reacting  of  wt  chloride  present  Such  Con  40  However,  visible  wt  chloride  the  the  conditions  is  no  40 be  high  has  that  with  reacts  ferrous  powder  iron  that  film  is  the  inconsistent  of  prevent  at  on  temperature.  layers.  but  with  a  inhibiting layer layer  be  film  one  a  Iron  treated  was  lower  and  observation  chloride  sulphur  chloride  sulphide  was  to  sulphide  layer,  surface  between  chloride..  surprising•that  interface  ferric  by  by  the  Metallic  suspended  chloride  decomposed  iron  of  distinguishing  ferrous  be  on  -  The  iron  thin  formed  layer  ferrous  this  a  divided  was  at  might  somewhat  phide  of  seem  powdered  substrate  on  chloride  would  that  of  ferric  metallic  S.S2CI2  possible  by  ferrous  that  way  formed  Reactions  observation tion  no  solution.  inhibited  When a  is  59  and  thus  when protected detectable  -  60 -  3.2  Decomposition  of Other  3.21  Decomposition  of  3.211  Reactivity The  was  studied  (Appendix mined  A).  but  +  ities  with  2  -»•  2  rate  This  pure  mixture.  PbCl  rate,  chloride  (Pine  Point) this  react  galena  of galena  with  concentrate was  deter-  3S  erratic. of chemical  of  The  effect  slowly added  have  impur-  sulphide  at a useful  i t was  might  sulphur  Determination catalytic  were  observation,  reaction  was  rate  chloride  when  small  to the  amounts  reaction  inferred  that  some  c a t a l y z e d the  chloride.  Catalysts.  of synthetic lead  of various sulphide  investigated  initially  of  - corresponding  chemicals  +  2  or sulphur—sulphur  i n the n a t u r a l galena  reaction  galena  a synthetic lead  impurity  3.212  chloride  of the r e a c t i o n  d a t a were v e r y  I t d i d , however,  From  Chloride  Galena  sulphur  Point  m a t e r i a l d i d not r e a c t  sulphur  natural  a Pine  the p o s s i b l e e f f e c t  on t h e r e a c t i o n  solutions. of  S C1  eliminate  prepared.  Sulphur  C-6) t o be:  the experimental To  using  (PbS) with  The s t o i c h i o m e t r y  (Appendix  PbS  and S y n t h e t i c  of galena  initially  by  Galena  of Natural  reaction  Sulphides  by a d d i n g  chemicals  with  small  sulphur  on t h e chloride  quantities  to a l l the i m p u r i t i e s  ( ^ 0.1  was g)  present  in  the  natural mineral  chloride  and  the  sulphide  lead  succeeding plete  reaction  trial  and  found  to  the this  was  7:  a  refluxing  the  lead  method  in  active  s i l v e r - b i s m u t h and of  materials  found  Effect of  of  PbS  nil  S  2  C 1  2  3  2  combinations  were  Data  on  active  the  Rate  of  T°C  % (of  Reaction 1 g sample)  135-40  0  .  0.5  »  8  »  «  »  4  »  "  »  12  Ag S,Sb S  3  »  »  "  75  Ag S,Bi S  3  "  »  »  94  2  2  2  The  reason  for  the  possibilities  are  suggested.  chlorides  form  M  or  BiCl  ~  M  complexes + +  SbCl  ~  catalytic  with  (58).  in  Reaction  3  2  2  + +  3  this  Ag S,As S 2  two  2  By  7.  " 3  incom-  SCI  2  2  of  in  until  catalytically  Time (minutes)  2  so  observed.  catalyst  be  with  Ag S As S ,Sb S ,Bi S  was  omitted  A d d i t i v e s on  Solvent  reaction  silver-antimony. to  sulphur  experiment,  were  Table  Various  Synthetic  M a t e r i a l added C 0.1 g o f e a c h chemical)  in  of  Complete  this  sulphide  the  mixture  sulphide.  chemicals  system are p r e s e n t e d  Table  to  -  observed  various  of  error  effect  61  synthetic lead  tests  be  -  -  the  effect  i s not  Antimony general  Complexes  and  known,  but  bismuth  formula of  this  type  may  be  -  involved  in  reacting  surface.  ment  silver  of  for  such  the  an  If  Is  compounds  chloride. be  transport  3.213  may  Silver  galena  catalyst)  of  with  are  catalyzed  system  (II) in  by  their  lead  chloride  role  then  or  from  the  Alternatively,  strong  oxidant of  formation  (59)  lead  the  require-  solubilize silver  reaction  mixture  to  the  weighed  sample  give  much  lyst  in  more  the  mineral  in  reaction  ClI)  and  might  sulphide  small  will  be  in  Pine  with  data  Galena  the  reaction  for  (with  15.  chlorinating  For  a  and  reaction  reagent was  and  than  pure  solvent.  this  way  by  cooling  The  active  Obviously  as  the  found  The  for  data the  rate is  on  a to  cata-  natural rates  of  the  of  reaction  present  reaction  catalytic effect  the  adding  was  initial  the  of  of  the  of  to  addition  catalyst  extent  on  this  before  reacting  indicate  of  sample  Pine  added  added  method  chemicals.  obtained  Increasing  gram  This  results  without  was  temperature  mineral.  of  measurements  one  ( ^100°C)  amount  an  Point  catalytic material  reproducible of  on  chloride  Figure  fresh  initially  mixture.  reaction.  of  reaction  a  in  desired  obtained  only  of  temperature  form  uncatalyzed  sets  sulphur  completely high  there  a  the  reaction,  at  the  is  Experiments  shown  mineral  when  Is  stabilize  Representative  the  this  product  chloride.  Results  Point  of  -  unexplained.  intermediate  sulphur  62  in  increases  -  63  -  35  TIME (MINUTES) Figure  15:  R e a c t i o n o f -150 + 200 m P i n e P o i n t Galena w i t h 10 wt. % S.S C1 2  a  C a t a l y z e d r e a c t i o n a t 40°C.  b  Uncatalyzed  r e a c t i o n a t 70°C.  -  64 -  TIME (MINUTES) 1/3 Figure  16 - P l o t  of r  Reaction with  [l-(l-R)  ] v s Time  o f - 1 5 0 + 200 m P i n e  10 wt %  S.S C1 0  0  f o rthe Catalyzed Point  Galena  -  eure °  17:  Plot  of r  Reaction with  10  o  65  [l-(l-R)  o f -150 wt  -  %  +  ] vs 200  S.S C1 0  0  m  Time Pine  for Point  Uncatalyzed Galena  -  The  rate  phur  chloride  rate  once In  of  was  66  reaction found  to  a l l solids  were  figures  and  16  -  of be  Pine  Point  Independent  galena of  the  with  sul-  stirring  suspended. 17,  data  f o r the  c a t a l y z e d and  un-  1/3 catalyzed vs.  r e a c t i o n s are  time.  plots  of  Table  8:  Reaction this  form  Rate  of  with  10  Uncatalyzed T°C  Ccm  rates  are  calculated  summarized  S.S c i  %  2  in  150 +  of  Reaction wt  i n the  —1  x  10  from  r [l-Cl-R) the  Table 200  m  slopes  )  Pine  . (cm  Point  Galena  Reaction Rate min  1  6 0.  1.55  80  1.77  50  0.89  70  0.83  40  0.36  60  0.43  30  0.19  The construct  rates  presented  Arrhenius  plots  (Figure  reactions.  catalyzed  reaction  was  A  value  15.4  similar  Energies  reaction  uncatalyzed  catalyzed  of  reaction.  The  2  i n Table  18)  Kcal  8 were  f o r the  activation  calculated -  10^)  x  3.32  Calculated Activation  of  8.  Catalyzed T°C  5  ]  Q  2  Reaction Rate min  form  90  3.214  the  plotted  to  be  mole  1  catalyzed  energy  for  17.6  2  was  used  -  the  Kcal  calculated  to and un-  mole for  Figure  18:  Arrhenius  Plots  Uncatalyzed Pine  Point  (b)  for  Catalyzed  Reactions  Galena  and  10  of wt  (a) -150  %  and +  200  S.S„C1„.  m  -  These of  stirring  68  -  a c t i v a t i o n energy on  the  reaction  values,  rate,  and  the the  lack  of  effect  linearity  of  the  1/3 plots  of  r  [1-Cl-R)  determining both  step  is a  the  ments  various were:  contact A  gold  indicate that  phase  arsenic,  lead  and  sulphide values  More were  added  antimony  sulphur  silver  matte  observations  than  made  and  chloride  in  reacted  the  gold  and  Chalcopyrite  3.221  Results  the  Experiments  40  r e a c t i o n was  2CuFeS  0  The this  Appendix  +  best  study A)  but  solid  on  ( C u F e S ^ ) was wt  %  5S„C1  •>  by  found The  +  at  the  a  low  significant temperatures  reacted  galena  silver  with  sulphur  content  of  residue.  Chloride  Chalcopyrite  to  react  overall  (Appendix  2FeCl„  experi-  residue.  with  Sulphur  Phoenix  available chalcopyrite contained  Point  reaction  S.S2CI2.  determined  Pine  solid  also  of  with  no  was  of  reaction  sulphides  added 90%  on  of  catalysis  based  Decomposition  for  rate  reaction  rate  matte  3.22  completely  the  leaving  the  Chalcopyrite  the  bismuth  in  of  on  during  found  of  boundary  the  Observations  chemicals  with  chloride. the  chemical  Miscellaneous Qualitative  on  time  cases.  3.215  of  ] vs.  C-7)  rapidly  stoichiometry to  2CuCl  in  a  used  be:  +  form  amount  and  of for  14S  suitable pyrite  (see  chalcopyrite  -  decomposition Analysis  of  the  the  for  90  minutes  due  contained  amount  of  pyrite  residue at  7Q°C  90%  of  are  was  -  not  from  a  showed the  s i g n i f i c a n t l y attacked.  chalcopyrite that  the  sample  water  original pyrite  leached  insoluble  but  no  resi-  significant  copper.  Representative Phoenix  69  chalcopyrite  shown  in  plots  of  reacting  Figure  19.  ] vs.  time  percent with  These  40  data  reaction wt  %  are  vs.  S.S^Cl^  plotted  time  for  solution  in  the  form  1/3 r  [l-(l-R)  30-70% the  reaction,  initial  period  The the  of  of  stirring  particles  rate  these  in  the  of  the  (penetration)  were  summarized  Table  Table  9:  in Rate 40  wt  fast  -  the  calculated  140  that no  not  20, for  The  reason  to  of  various  for  suspend  effect  sections  rates  of  known.  apparent  on  the  (30-70%  re-  reaction  temperatures  s.s ci 2  (Penetrat  i o n ) of  CuFeS " 2  2  P e n e t r a t i o n Rate min  x  80  10 . 6  70  5 . 4  60  2 . 7  50  1.3  mesh  range  required  straight  (cm  +  is  the  9.  T°C  -100  In  linear.  had  Figure  of React ion %  above  liquid  of  are  20.  reaction  -  Using  plots  Figure  plots  rate  reaction.  action)  in  Phoenix  CuFeS  io ) 5  in  and  -  801  40 wt. % S . S C 1 2  2  70  -  0  10  20  30  40  50  60  70  80  TIME (MINUTES)  F i g u r e 20;  1/3 P l o t of r [ l - ( l - R ) ' ] v s . Time f o r -100 + 140 m Phoenix CuFeS Q  2  i n 40 wt. %  S.S C1 . 2  2  -  3.222  Calculated Activation  The  rates  summarized  Arrhenius  plot  of  this  plot  corresponds  Kcal  mole  ±2  stirring is  on  the  controlled  3.223  bornite  by  that in  40  metal  %  chloride, pure or  sulphur-sulphur  and at  slope  of of  that  effect the  of  rate  reaction.  Copper  Minerals samples  chalcocite least  as  of  (Cu S) 2  fast  as  2  reactivity of  two  from zinc  Pine  concentration  40  by of  zinc  A)  various  wt  %  Sulphur zinc  S.S C1 . 2  Point  - were The  sulphide  Mines from  i s summarized  in  -  extent of  Table  in a  Ltd., the  treated  conditions  2  Chloride  concentrates  concentrate  Appendix  under  by  Sulphide  chloride solutions.  concentrates  sulphur  iron see  The  uncharacterized  attacked  Zinc  sphalerite  (for analyses,  Other  react  2  samples  high  lack  construct  S.S C1 .  is also  of  the  indicate  (CuS),  minerals  wt  on  to  energy  boundary  on  used  reaction.  and  again  phase  covellite  these  the  value,  chemical  i n v e s t i g a t e the  marmatitic  and  a  (Cu^-FeS^),  relatively  the  This  9 were  activation  experiments  To  Mine  an  reaction rate  Decomposition  sulphur  to  for  Qualitative  Copper  of  ^.  21)  Energy  Table  Observations  chalcopyrite  a  (Figure  in  Qualitative  indicated  3.23  -  The  an  16.4  73  and  Sullivan with  of  reaction  temperature 10.  _  Table  10:  Reaction  74  -  of Sphalerite with  Substrate  Reaction  P i n e P o i n t ZnS C - 1 5 0 + 200 m)  tt  tt  40  wt  10  min  40  wt  30  min  Conditions  %  S.S_C1 2  at %  2  100%  tt  133°C  0  min  40  wt  40  min  at %  0 . 8  2  at  S C1  10  0. 9  2  146°C  2  S u l l i v a n ZnS (-70 + 140 m)  0 . 8  0  2  S.S C1 at  min  % Reaction (weight l o s s )  146°C  ioo% s c i 10  S CI  31.3"  0  133°C  S.S C1 2  at  3 2.4"  2  150°C  R e s i d u e a s s a y ( 6 0 . 5% Zn , 0.4% P b , 4.5% Fe ) s h o w e d o f Zn i n o r i g i n a l s a m p l e was solubilized.  From  the table  pure  (Pine  phur  chloride despite  (Table  Point)  material  that  is virtually  the favourable  the  (-1)%  relatively  unreactive  calculated  to  free  sulenergy  1) f o r t h e r e a c t i o n  ZnS  It  seems  is  formed  further  i t i s apparent  18  +  S C1 2  probable on  -»••  2  that  ZnCl  2  +  3S  a protective layer  the sulphide  surface,  of zinc  and a c t s  as  chloride  a barrier  to  reaction. The  Sullivan  zinc  concentrate  contains  an  appreciable  -  amount not  (9.0%)  removed  of  after  sulphur  chloride  zinc  iron It  treatment  i n the  protective  (which film  hindered  by  solution  i n the  zinc  ite  concentrate 2  no  (as  at  2  case  was  of of  (Appendix  A)  with  and  chlorine  significant  thermodynamic  can  be  sulphur From  is  ratio  of  Sullivan  formation  mineral  zinc  of  a  surface i s  sulphide  in  solid  Cu)  qualitative  S C1 2  amount  samples at  2  of  of  loss  a  136°C,  40  at  -  reaction  of  concentrate f o r copper  in  the -  wt  %  60°C. reacted  Table  observed  chlor-  molybden-  molybdenite  calculations  the  tests  in sulphur  2  weight  of  (MoS^)  Chloride  s a t u r a t e d - S C1  e x p l a i n e d by  (0.4%  Sulphur  1).  The  these  copper the  after  samples  treatment  chloride. these  unattacked  ditions.  the  iron  by  molybdenite  experiments  with  of  with  1.3:1.  the  the  Molybdenite  consistent  negative  at  treating  by  of  iron)  reactions  but  gave  9.0%  solid  The  was  case  by  any  content  i n the  pyrrhotite  concentrate  Iron.  decomposed  chloride  ( 1%)  mineral  4.5%  as  insoluble,  zinc  studied  150°C,  predicted  small  was  and  mineral.  reactivity  solutions  water  only  contained zinc  solution  Sullivan  that  simultaneous  ide  S.S C1  of  material  Decomposition The  In  of  -  The  contained  i s suggested  concentrate  3.24  in solid  in flotation.  residue  to  iron  75  by  Thus,  results, sulphur  i t i s apparent  chloride  i t is possible  to  under  that  a wide  selectively  molybdenite range  of  decompose  con-  -  other the  sulphides  presence  such  of  as  3.31  Requirements  i.  a A  surface  directly The  i i i .  or  the  metal  the  fusion  proposed  consistent i.  The rate  or  a  S (n n  mixed  the  and/or  by of  are  diffusion a  1-4),  a  dis-  bonds  of  the  free  trans-  radicals  reaction  such  as  of  products  dissolution  three  a  and  boundary  steps  dif-  layer.  mentioned  studied  above,  should  be  observations:  calculated  range  of.16-22  higher i n the  significant  (possibly  mineral,  reactions  consistent with and  =  through  f o r the  the  c h l o r i d e or  products  deposit  following  in  steps:  s u l p h u r - c h l o r i n e compounds  of  solid  energies  three  surface,  as  surface  the  are  are  lack  such  least  chloride  c h l o r i d e forms  intermediate  mechanism  data  control  sulphur  i n c o r p o r a t i n g the  with  at  sulphur  sulphur  r e a c t i o n products  reaction(s)  the  of  activation  values  of  of  mineral  Besides  in  Mechanism  involve  component(s)  of  galena  Results  r e a c t i o n of  mineral  -S-S-Cl,  Establishment at  any  the  nature)  •CI  the  will  product to  in  Reaction  r e a c t i o n i n which  generation  itory  Experimental a  of  sulphide  sociation  i i .  for  mechanism  metal  c h a l c o p y r i t e or  molyhdenite.  I n t e r p r e t a t i o n of  with  -  pyrite,  3.3  The  76  from  Kcal/mole.  rate  control  than  values  liquid  stirring  experimental  by  These  chemical  expected  state effect  (56). in  the  for  rate  Also, reactions  -  of  pyrite,  fusion  in  galena a  77  and  liquid  -  chalcopyrite  boundary  layer  indicates i s not  that  rate  dif-  control-  ling . i i .  Evidence solid  i n d i c a t i n g the  reaction  sphalerite, In  the  was  obtained  pyrrhotite,  and  pyrite  of  metallic  solutions  formation kinetics  of  products  reaction  chloride  formation  was and  iron  visible  in  the  in  reactions  with  form  deposits  films  on  the  ( i n pure  d e f i n i t e evidence  obtained  stable  of  S^Cl^).  sulphur-sulphur of  of  the  of  surface  film  parabolic metal  reaction  surface.  1/3 i i i .  The  linearity  for  the  the 3.32  be  that  The  Role  solvent  are with  polymerize > y  of  pyrite,  reaction with  a  r  [l-(l-R)  galena,  mechanism constant  ] vs.  time  and  chalcopyrite  for  these  interface  materials  velocity  in  ^  molecules  Sulphur  the or  mechanisms  role  and  sulphide may  known  form  as to  a  in  -  that  the  be  S  g  the  reactions  present  initially  should small  These  significant of  -  to  in  n  considered.  (n  n of  =  molecules  Long  carbon  1-4)  sulphur  f r a c t i o n of  rings.  insoluble  S  be  S  reactions  minerals. a  either  product  assume  instead to  applicable  sulphur  intermediates  polymers are  of  formed  is reasonable  molecules chloride  of  considering  It  ^  of  consistent  investigated, the  the  plots  reactions.  In  in  the  reactions  indicate must  of  will  long  chain  chain sulphur  disulphide  and  -  may  therefore  ide  while  of  a  their  large  sulphur  have  a  fraction  of  chloride. be  at  phase  boundary,  of  viscous S  molecules  IN  boundary. chain eral  dissolution  boundary  This  sulphur  the  would  then  thickness  of  would  depend  the  diffusion layer,  of  and  as  observed  ucts  from  the  of  a  passive  on  the  ferric tion  imply are  a  film  through  conversion  by  of: a  the  The  such  a  i n which  r e a c t i o n at  solvent.  rates  molecules  or  mechanism  formed  reaction  c o n f i g u r a t i o n at  O  by  the  the  the  chloride  sulphur  mixed  formed  would  be  associated  interface  possible role  studied  (or  the  is  mineral  mineral  by  product  in  sulphur  sulphur  presence  a  long  min-  steady  reaction  sulphur  removal,  viscous  boundary  with  velocities  of  high  activation  the  reactions  experimentally.  reactions  function  of  c h l o r i d e through  constant  Another  In  chain  of  S„ N  solution  of  long  the  chlor-  surface reaction.  process  and  in  by  determining  relative  sulphur  the  This energies  on  an  Increased  sulphur  factors  dissolve in  state  i n pure  equilibrium S  molecules  surface,  be  diffusion  layer  to  may  molecules  Thus,  could  a  S  -  solubility  solubility  rate a  poor  78  In  the  for  dissolved sulphur  removal  surface  inhibitory)  -  of  thus  film, of  solid  reaction  preventing solid  in  metal  the  the prod-  buildup  chloride  surface. case  either  c h l o r i d e so  r e a c t i o n can  of  pyrite,  sulphur  i n c r e a s i n g the  may  accomplish  solubility  that  removal  by  a  occur  rapidly  enough  of  this  product  dissolution-precipitato  maintain  a  clean  -  reacting plexes  surface  with  chloride  or  metal  by  79  -  forming  chloride  precipitation  unstable  reaction  occurs  away  or  transitional  products from  the  so  that  com-  metal  reacting  sur-  face. Alternatively, coherent wetting will  layer the  not  3.33  Surface  metal  active  ism of  or  by  culated  or  since  two  M-Cl  chloride  bond  for 51  S-S and  the  pure  most  lower  via  can by  of  a  preferentially  chloride  react  product  an  with  a  dissociation  which  being  Sulphur  values  S-Cl  Kcal  of  Cat  then  mineral into  attack  the  associative  mechan-  formed  remnant  as  a  These  per  mole  of  unlikely  that  the  activation than  those  Cor  Chloride  25°C) have  bonds.  dissociation  calculated  significantly  formation  molecule.  and 60  atoms  molecule  energy  a  by  metal  ways:  bonds  Average  by  that  chlorine  -S-S-Cl  i t appears  proceed  as  of  Reactions  C60)  product  molecule  Dissociative  respectively values  i n one  such  sulphur  3.331  so  prevent  surface.  chloride  forming  an  chloride  surface the  sulphur  surface  with the  to  might  Reactions  species  surface  metal  mineral  adhere  The or  of  sulphur  S^l)  energies  been  values  bonds.  type  of  (16-22  r e q u i r e d f o r bond  are  From  observed  cal-  these  reactions  mechanism Kcal)  are  rupture.  3.332  -  80  -  Associative Reaction  of  Sulphur  The  dissociative  alternative  associative Interacts rary  a  bond  experimental respect  to  in  which  before In  residual  In  a  mineral  sulphochloride  described  and  the  broken.  possible not  with  S..C1..M  pletely be  mechanism  to  surface the  this  the  Chloride mechanism  is  sulphur  chloride  to  at  form  least  s u l p h u r - c h l o r i n e bond  case  a  surface  an  molecule a  tempo-  is  intermediate  comcould  ( m e t a l - s u l p h u r - c h l o r i n e compound),  S-Cl the  bonds.  However  technical  conditions  of  decomposition  literature  this  to  such  study  crystalline  compounds  and  are  with  under  unstable  metal  are  the with  chlorides  sulphur. The  after  the  small  (S^,  n  chlorination  =  1-4)  sulphur  reaction  will  molecules  polymerize  remaining (to  S  or o  S^j,  N >> 8)  leaving  adhere  to  the  3.34  Models  metal  reacting  for  chlorides  are  metal  Metal  sulphides  presented Scheme  steady In  state  this  chloride  case,  in A  Sulphide-Sulphur  layer rate  through  (as  Figure of  or  may  not  reaction in  Chloride  of the  sulphur  Reactions chloride  previous  sections)  22. 22  represents  polymeric  control  the  of  discussed  Figure of  may  surface.  Some p o s s i b l e modes with  which  may  viscous  S^ be  the  formation  molecules by  sulphur  on  diffusion film,  by  the of  the  of  a  surface.  sulphur reaction  A.  MS  S,CL / S 2 2 8 f l  MS S /MCI N  n  t, >0  to=0  B. MS  JC.  MS  SCI / S 2 2 8 to =0 s ci /s 2  2  8  SCI / S /MCI 2 2 8 n  MCIni  MS S C I / S ->• MS MCI s , c u / s n MCIn t,>0 to»0 2  MS  to = 0  2  8  S C I / S / MCI„ 2  2  8  t, >0 F i g u r e 22:  Models f o r the R e a c t i o n o f Sulphur C h l o r i d e with Metal  Sulphides  (see t e x t , S e c t i o n 3.34)  oo t—  1  -  at  the  of  S  SN / M C l n or  XT  N  a  If to  form  such  in  a  phur  dissolved  in  catalysts  inhibit  the  effect  should  effect  was  of  likely  i t is  the  so  metal  a  a  consistent chloride tion  metal  consistent  hotite  where  to  period  decreases  for to  due  to  chloride  rates  porous  a  very  sulaction  is  to  this  but  no  such  control  by  the  seems  properties  on  porous the  small  or the  on  a  un-  of  sulphide Formation  reacting  surface  the  the  diffusion  reacting  rapid  the  -  is  iron-sulphur  sphalerite  as  an  dense.  protective value  of  sulphur.  the  of  the  thickens  increased product  on  of  layer  initially of  formation  kinetics  reactions  build-up  then  sulphur  the  product  layer  and  are  reaction  film  rate  of  i f the  pyrite,  represents  chloride' layer the  of  galena  amounts  galena  sulphur  expected  product.  be  the  the  of  Also,  polymeric  chloride may  large  consider  parabolic as  with the  to  dissolution  be  reaction  basis,  of  22  chloride  the  sulphur  is  rate  film  decreases  dense  the  a  with  a  layer  metal  metal  of  this  Figure  reaction:  rate  reactant  of  in  reaction  reaction  of  Such  porous  On  i t would  require  viscous  reasonable  B  layer  surface. of  a  viscous  chloride  Scheme adherent  of  the  p Th yJ s i c a l  chloride.  etc.)  observed.  formation  not  J  form  complete  Sb  in  h yJ  *  factors.  did  sulphur  CAg,  occur  the  does  the  formation  these film  but  chloride  -  interface,  of  sulphur  a l l cases  sulphur  the  S. C1./S„ 2 2 8  combination  with  of  -  l T  82  reac-  path  for  Formation interface and  pyrr-  corresponding  layer. dense  Then  the  adherent  -  layer  prevents, a c c e s s Scheme  reaction adhere and rate  control  reaction  ring  away  could  be  by  energy  indicate  rate  control  galena  Cwith  pure  pyrite  Cwith  40  wt  Thus,  on  the basis  ponse  i s consistent  depend  on  metal  then  parabolic  Cdepending  chloride  on  reaction  and  metal  chloride)  linear  that  to reaction  forms  on  stir-  kinetics.  pyrite  and  on  chalco-  are  rate  in  If  surface  while  layer  observed  i f the  control  res-  chloride  product.  are  of  i s by  metal surface  observed.  from  Chlorination  Elemental  sulphur  i s a product The  evidence  sulphur  passivity  of the f i l m )  adherent,  .  with  a coherent  or v i r t u a l  kinetics  S CI  high  of experiments  chloride  Sulphur  and  surface  the d i f f e r e n c e s  Elemental  sulphides  or  of rate  of the experimental  product  i s non  and  scheme,  the  reaction  not  Clj).  the p o r o s i t y  product  surface  of the metal  kinetics  studied,  does  dissolution  diffusion  the r e s u l t s  probable  sulphides  chloride  3.4  % S.S  the nature  this  phase  by  surface. chloride  either  In t h i s  independence  by  with  sulphur  i t seems  of metal  the surface.  and  C  study,  product  In t h e r e a c t i o n s values  to the  sulphide—sulphur  or i s removed  liquid  Scheme  this  chloride  chloride  surface from  kinetics.  activation  a metal  the metal  to the sulphide  precipitated  -  of the sulphur  C represents  i n which  83  of Metal  of reactions  reactions  were  Sulphides between  normally  -  done  at temperatures  excess  sulphur  such  chloride  rhombic  or monocllnic  S.S2CI2  solution  itated  sulphur  rate  and/or  tion  sites.  cipitated tals  by  by  are easy  that  the sulphur  present.  form!  c a n be  cooling  crystallized  C29).  The  size  c a n be  controlled  addition  of seed  crystals  sizes  dissolved  in  Elemental,sulphur  crystals  Two  from  84 -  of rhombic  from  of the p r e c i p -  by  the  cooling  t o a c t as  sulphur  Cin  nuclea-  crystals 2 3 .  pre-  solution  a r e shown  i n Figure  Such  crys-  to f i l t e r  and wash,  a n d a r e f r e e - f l o w i n g when  dry. Some  chloride  sulphur,  both  chlorine  c a n be  with  Inorganic  distillation solvent this  and  the surface  solvents  sulphur  removed  hydrochloric A  such  by  liquor  down  of c h l o r i n e  washing  crystals  recovery  low  the  and of  after  levels water  i s hydrolyzed  from  surface  the  remaining  to very  contents  procedures  The  tetrachloride,  s t r u c t u r e - by  lost  crystal  washing  f o r separate  procedure  and  by  Chloride  removed  this  i n the  i n the bulk.  as c a r b o n  the c r y s t a l  acid,(30)  summary  various  and  chloride.  c a n be  disrupting  Chloride  present  removed, a n d r e c o v e r e d  o f t h e wash  treatment  without  after  on  i s always  to  -  washing. aqueous  process.  of sulphur  i s presented  crystals  i n Table  11.  -  85  -  3CM  S U L P H U R  C R Y S T A L L I Z E D  S - S C I  2  Figure 2 3 :  F R O M  S O L U T I O N  2  Rhombic Sulphur C r y s t a l s P r e c i p i t a t e d from Solution.  S.S C1 2  2  Tab.le  11:  Chlorine  -  86  -  Content  of  Precipitated  Hash. S e q u e n c e  2  excess  2)  washed i n filtered  3)  water washed and filtered  44 at  2  Potential  3.51  Useful The  chloride  has  sulphur.  and  at  The  and  sulphur  covered sulphur. 95°C,  by  so  study  of  of the  which  may  the  reactions (above such  sulphur  I t was  are  be  be  crystallize  sulphur  at  be  (Table of  1)  the  self-  not  required.  completely  re-  dissolved  temperatures  c r y s t a l s can  that  (dissolved)  points  is  the  (pyrite,  and  thermally  can  in  rapidly  exothermic  atmospheric)  to  can  minerals  boiling  can  sulphur  found  chloride  reactions  solvent  saturated  Chloride  useful  chlorides  reactions below  that be  sulphide  metal  S  Chloride  sulphur  form  crystallizing rhombic  Sulphur  sulphides.  These  the  for  indicate  certain  to  pressure  cooling  stable  0.03  Sulphur  conditions,  product  By  hr.  properties  temperatures  used,  sustaining  this  galena)  elemental  solutions  1  of  decompose  chalcopyrite,  0 . 12  c r y s t a l s p r e c i p i t a t e d from  treatment  appropriate  occur  of  several  completely  and  M e t a l l u r g i c a l Uses  results  CI  1.54  for  Properties  metallurgical  and  CCl^  %  drained  solvent  mesh r h o m b i c 6Q-50°C.  3.5  under  ttt.  1)  -28 + S C1  Sulphur  below  produced  -  (Appendix form  H,  (.47)) i n a  c o u l d be Other  were so  found  metal  to  selective  of  be  of  chalcopyrite the  basis  are  of  Specific  3.521  Pyrite has  u n r e a c t i v e to  sulphur  i n the  treatment  Potential  been  shown  Uses  that  sulphur.  On  the  i s proposed  non-ferrous  S.S C1 . 2  action to  f o r the  elemental  will  The  2  will  oxides  be  be  and  decomposition  and  presence  of  of  sulphide  decomposition the  of  some  chloride  chloride.  decomposition  molybdenite.  potential  s u l p h i d e s by  pyrite  dissolved  pyrite  the  f o r Sulphur  sulphur  the  are  results,  by  of  sulphur  sphalerite  these  sphalerite)  v a r i o u s components with  this  dust. pure  decomposed  recover  from  in  (molybdenite,  uniformly  (61)  Sulphur  proces-  sulphur  suggested.  3.52  It  free  reactions of  galena  for metallurgical  chlorides  sizes.  accomplished  presence or  of  of  selective  i n the  -  and  sulphides  be  such  galena  ses  handled  essentially  can  of  On  range  decomposition  concentrates Examples  easily  87  In by  generate reaction.  with  these  results,  treatment  proposed  to  with  and  25-40  convert  non-ferrous  of a  a  wt  process  pyrite  to  concentrate  process,  chlorides)  f o r reuse  and  c o n t a i n i n g 25-40  this  oxygen  Any  completely  oxide,  (metal  chlorine  be  iron  reaction  products  treated  of  metallurgical  metals.  solid  chloride  basis  s u l p h u r , pure  decomposed  can  Chloride  wt of  iron  i n the metal  % this  re-  chlorides  sulphide chlorides  %  -  on t h e s o l i d will  will  be  The  n o t he  liquid  phase from  cooled to c r y s t a l l i z e  the s u l p h i d e c o n t e n t  s e p a r a t e d , and composition is  converted  step.  scale  the d e c o m p o s i t i o n  of p y r i t e  c h l o r i d e has  de-  process  and  crystallization in this  process,  of product  s t u d y , and  been a c c o m p l i s h e d  (9)  the sul-  the o x i d a t i o n  i n a bench  experiment.  r e a c t i o n s , and non-ferrous  the  process  are  sulphur i n a convenient  (expected)  metals  purity  o f the  the  form,  iron  fast  oxide  and  produced.  Galena Results  of experiments  shown t h a t g a l e n a sulphur chloride  can be  have  sulphur-  mild conditions  i s u n r e a c t i v e under these c o n d i t i o n s . a process  i s proposed.  In t h i s  be  concentrates  c o m p l e t e l y decomposed by  these r e s u l t s ,  centrate w i l l  on g a l e n a  s o l u t i o n s under r e l a t i v e l y  that sphalerite  trate  sulphur  flowsheet f o r t h i s  o p e r a t i o n s i n the proposed  production of elemental  From  reaction  s o l u t i o n r e c y c l e d t o the  Some a d v a n t a g e s o f t h e p r o p o s e d  3.522  oxide  E.  p h u r have been d e m o n s t r a t e d ferric  and  an amount o f s u l p h u r e q u i v a l e n t  A schematic  the u n i t  decomposition  and  to oxides  of the p y r i t e , product  the remaining  shown i n A p p e n d i x Of  of  -  be r e c o v e r e d b y a q u e o u s l e a c h i n g o f th_e i r o n  product.  to  residue w i l l  88  f o r treatment  of l e a d concen-  Cproposed) p r o c e s s , l e a d  decomposed by  sulphur-sulphur  con-  chloride  -  solutions or  containing  bismuth  as  a  certain  catalytic be  -  89  amount  agents.  reaction  will  chloride  leaving  unreacted  chloride  will  be  recrystallized  filtered  off,  and  duction  of  will  recovered  be  chloride  lead  leached  metal by  separation  proposed of  elemental  minerals  other  lysts)  galena  chloride for  solution,  melt  for  recycle.  from  the  Lead  pro-  Sulphur  sulphur-sulphur  decomposition' r e a c t i o n . proposed  process  incorporates  mixed  is  A.  shown  in  or  shown  react  be  to  react  conditions  very  small  silver  in  metallurgical  concentrates  Consumption  antimony  under  a  lead-zinc  will  solutions  chloride  chalcopyrite of  centrates be  the  the  this  lead  residue.  cooling a  of  of  chlorine  since  and  and by  in  the  pres-  bismuth  (as  cata-  with  sulphur-sulphur  which  other  minerals  slowly.  Molybdenite  sulphur  can  in  galena  been  Molybdenite  basis  a  sulphur.  and has  pyrite)  3.523  as  this  from  than  silver  chloride (e.g.  sphalerite  process  lead  produces  of  products  dissolve  by  antimony  F.  The  ence  for  solid  and  to  chlorine  in  silver  brine  crystallization  used  flowsheet  Appendix  and  The  hot  electrolyzed  solution  schematic  in  of  and  these  to  found  solutions galena  results,  containing  purified  solutions  was  by  be  under  are i t  to  conditions  completely is  proposed  deleterious treatment  selectively  unattacked  decompose  sulphur-  which  decomposed. that  amounts  with  in  by  On  molybdenite  the con-  these  minerals  sulphur-sulphur  chloride  the  of  pyrite,  impurities.  The  -  solid  residue  remove  from  soluble  metal  Cleaning molybdenite a  lower  of  3.53  in  the  molybdenite  chloride  have  high  has  in  been  the  a  by  recovery  since  chloride  the  Use  shown of  so  of  no  to  molybdenite.  impurities)  selective  making  of  results  in  leaching  chloride  a  high  molybdenite  grade  will  be  de-  leaching.  of  Sulphur  that  sulphur  sulphide  Chloride chloride  minerals  However,  metallurgical  of  sulphur-sulphur  advantage  molybdenite.  as  unattacked  amounts  recovery,  concentrates  sulphur  and  leached  f l o t a t i o n frequently  processing  galena,  the  acid  by  Problems It  from  be  concentrates  would  by  chlorides  would  small  with  composed  reaction  of  molybdenite  product  -  (removal  final  solutions  this  90  -  the  reagent  may  be  useful  particularly pyrite, use  poses  a  of  sulphur  number  of  prob-  lems . Sulphur metals  (iron,  suitable  is  titanium,  material  Preliminary has  chloride  tests  must  copper, be  (Appendix  excluded  from  production chloride  sive scale  of  chloride  the  undesirable  Also,  sulphur  using  —  see  process  indicated attack  by  a  G.)  of so  a  equipment. monel  sulphur so  alloy  chloride. water  chloride  hydrolysis  number  Appendix  that  readily,  sulphur  to  to  products  must  be  avoid (hydrogen  dioxide). chloride  i t must  application.  for  hydrolyzes  system  sulphur  so  to  any  and  odour,  G)  corrosive  lead  found  significant resistance Sulphur  highly  be  is  toxic  completely  (51)  and  enclosed  in  has any  an  offenlarge  -  4.  sulphide  phur)  with  to  phur.  f o r e g o i n g , i t has  On  this  basis,  commercial  Conditions decomposition chloride. observed,  (II)  phur.  sulphur  %  by  phur.  %  dissolved  a n t i m o n y .or  lead  in  and  are  and  iron  sulphur and  when  and  chloride was  small  bismuth  were  complete  by  sulphur  reaction  and  sulphur,  dissolved  chloride  quantities present  sul-  completely  containing  %  is  chloride,  completely  wt  sulphur  flota-  elemental  dissolved  40  for  of  the  galena  uniformly  containing by  for  (III)  chloride  Chalcopyrite  sul-  molybdenite.  complete  25-40%  be  extract  treatment  determined  sulphur,  decomposed  silver  the  the  sul-  formulated  react  containing  dissolved  been  which  (II)  to  chloride  was  in  can  have  chalcopyrite,  sulphur.  sulphur  chalcopyrite  and  in  been  products  found  partially  Galena wt  was  chloride  dissolved  posed  and  chloride,  only  also  that  chlorides  galena,  conditions  reaction  Pyrite  reacted  0-10  the  processes  pyrite,  Under  their  pyrite,  have  of  to  and  established  (containing  application  of  been  galena,  chloride  metals  concentrates  copper  pyrite,  sulphur  convert  potential tion  the  minerals  treated  wt  -  CONCLUSIONS From  in  91  as  but 0-10  decomsul-  containing of  silver  catalysts  -  in  the reaction  reaction are  rates  presented  reaction found  was  t o be  (40-150°C) surface  Table  i n Table  chemically of this  energies Under  the rates  of Rates  and A c t i v a t i o n  10 wt  % S.S C1  a. c a t a l y z e d a . 15.4 , -4 . . + . .,• 1.55 x 10 cm/mm - 2 K c a l / m o l e at 60°C b. u n c a t a l y z e d b . 17.6 -5 + 0.43 x 10 cm/min - 2 K c a l / m o l e a t 60°C  2  % S.S_C1  c  t o form  by  x 10~ a t 80°C  4  cm/min - 2  were  found  and e l e m e n t a l  the presence  16.4 Kcal/mole  to react chloride  sulphur.  of f e r r i c  chlor-  mixture.  of r e l a t i v e l y  chloride  v  and s u l p h u r - s u l p h u r  chloride  i s inhibited  21.3 + _. „ . .• . - 2 Kcal/mole  4  i n  1.06  chloride  ferric  i n the reaction  sulphur  x 10 cm/min a t 147°C  and s y n t h e t i c p y r r h o t i t e  solutions  with  A E^  1.96  40 wt  Reaction  Energies  % S.S-Cl  with, s u l p h u r  ide  range  40 wt  partially  reaction  were  Rate o f Penetration at T°C  2  This  reactions  substrate.  c  Natural  uniform  a n d t o be p r o p o r t i o n a l t o t h e  2  -140 + 200 m CuFeS  reactions  c o n d i t i o n s where  0  + 200 m P o i n t PbS  specific  i n the temperature  Solvent  -70 + 100 m Sullivan FeS  of  f o r these  of these  controlled  of the s o l i d  Substrate  -150 Pine  12.  study  Summary  -  Calculated values  and a c t i v a t i o n  observed,  area  12:  mixture.  92  pure  (Pine  and s u l p h u r - s u l p h u r  Point)  sphalerite  chloride  solutions  -  was  found  t o be n e g l i g i b l e  Some  iron  and z i n c  ide,  iron  (III) chloride  (Sullivan)  zinc  predicted The  phides by  removed  sulphur  structure  chloride pyrite,  removed  results  may  a  chlor-  marmatitic sulphur  to sulphur  by d e c o m p o s i t i o n  chloride. chloride  of metal  c a n be q u a n t i t a t i v e l y sulphur  chloride  carbon  - without  crystals.  which  c a n be  tetrachloride,  disruption  sul-  recovered The  crys-  partially  and  nearly  of the c r y s t a l  washing.  of this  be u s e f u l  galena,  (to zinc  with  inert  150°C.  calculations.  of rhombic  with  when  treated  t o be  chloride  - by w a t e r  The  found  contains  by w a s h i n g  completely  was  up t o  decomposed  and s u l p h u r )  produced  sulphur  crystallization  tallized  were  by t h e r m o d y n a m i c  sulphur  with  sulphides  was  -  3  at temperatures  concentrate  Molybdenite as  9  study  indicate  that  i n the m e t a l l u r g i c a l  and m o l y b d e n i t e  sulphur  treatment  concentrates.  of  -  5.  in  SUGGESTIONS  FOR  1.  o f the r e a c t i o n s  A study  S.S^Cl^  Cl^/CCl^  solutions  solutions  FURTHER  may  S.S2CI2  solutions  A study  of sulphur  ization  A study  (.including  reliably  resist  4. of  from  PbCl2  S.S2CI2  efficiency  studied  a n d maximum  used  should  i n S.S2CI2  of lead further  attainable  the  study.  crystallizalead  t o minim-  sulphur.  behaviour  indicate  iron  with  in this  affecting  of product  of the corrosion m o n e l ) may  certainty  of pyrrhotite  solutions  content  corrosion  be  reaction  and  % S and i n  more  the conditions  The p r o d u c t i o n should  wt  with  of the parameters  of the chloride  3. alloys  under  of pyrrhotite  >40  determine  f o r the incomplete  2.  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McElroy,  U.S.  Patent  CIM  Bulletin,  Application  -  Appendix  A:  99 -  Sources  and A n a l y s e s  Natural  Minerals  Mineral  Source  Pyrite  Sullivan CCominco  of  Used  in this  Study  Analysis 4 5 . 2 % F e , 5 2 . 4 % S, 0.7% Pb , 0 . 1 5 % Z n , Q.5% S i 0  Mine Ltd. )  2  Noranda  Pyrite  4 7 . 1 % F e , 52% 0.5% Si0  Mines L t d ,  S,  2  Pyrrhotite  Sullivan CCominco  5 7 . 0 % F e , 3 8 . 8 % S, 1 . 0 % P b , 1.8% Z n , 0.8%  Mine Ltd. )  Galena  P i n e P o i n t Mine CCominco L t d . )  8 2 . 0 % P b , 1 5 . 1 % S, 1.1% Z n , 0.03% A s , 0.05% Sb, 0.03% B i , 0.02% A g , Ca,Cu,Mg, Mn,Si < 0.1%  Sphalerite  P i n e P o i n t Mine CCominco L t d . )  6 3 . 8 % Z n , 3 1 . 5 % S, 0.4% P b , 1.6% F e  Sphalerite  Sullivan CCominco  5 2 . 4 % Z n , 2 9 . 4 % S, 6.4% P b , 9.2% Fe  Chalcopyrite  Phoenix (Granby  Molybdenite  Appendix  Reagent  B:  grade  Alice CB.C.  Grades Study  Mine Ltd. ) Mine Mining Ltd.)  A r m , B.C. Molybdenum  Corp  of Materials  Ce(S0 ) 4  27 . 6% C u , 2 9 . 6 % F e , 32.0% S a c i d i n s o l u b l e 5 2 . 1 % Mo, 3 6 . 5 % S, ) 0.4% C u , m a j o r i m p u r i t y SiO„  and C h e m i c a l s  2  1,10 -o-phenanthroline Na a c e t a t e FeCl .4H 0 2  2  Pb , Sn Technical  SCflowers),  CI CS,  acetone, C C l ^ As S , 2  Unspecified:  3  monel  Sb S , 2  3  alloy,  Bi S , 2  Fe  3  Ag S 2  Used  in this  Cu  8%  -  Appendix C-l  C:  Stoichiometry  Reaction  of Pyrite  100  -  Determinations  with.  Sulphur  Reaction conditions: T = 133°C, Reactants: S C1 , Sullivan FeS 2  Initial  sample  F i n a l sample C a f t e r wash, Loss *  •b  2  weight  1.000  weight p . 24)  l o s s xn w e i g h t .• , i n i t i a l weight gangue c o r r e c t i o n  A n a l y s i s of water s o l u b l e products: (after CC1 /CS w a s h , p . 24) 4  C-2  = 0.502  Reaction  g  0.241 1.00-0.03  - — r - r —  =  (vs.  of P y r i t e  Fe  Initial  %  pyrite  Analysis  Observed  Weight  „, „„ 24.9%  =  (total)  114  Fe  (ferrous)  trace  CI  (total)  227 rag  for stoichiometric  with  40  wt  2  Loss  n  Fe  %  S.S C1 2  Reaction conditions: T = 129°C, time Reactants: 40 wt % S . S C 1 , S u l l i v a n  Final  minutes  mg  2  Fe*  Observed  = 5  0.241  -—7—.—r  J  time 2  0 . 759  i n weight  '4. A. J pyrite reacted = *  Chloride  sample  sample  1.QQ0  weight  YTb^T'o  =  of water  soluble  ratio  .524  2  2  g  .192  reacted  =  0.523)  .808  i n weight  —  =  = 5 minutes FeS  2  weight  FeClg  3  X  1  0  products:  (vs.  °  =  1  9  ,  8  %  Fe  (total)  89  Fe  (ferrous)  trace  CI  (total)  f o r FeClg  =  0.523)  170  mg  mg  -  C-3  Analysis Initial  of Residue sample  Insoluble Residue  from  • S  :  1.317  HC1/HN0  3.9%  (51.4  mg)  3.1%  (40.8  mg)  of Pyrrhotite  Reaction  Conditions:  Initial Final Loss  Observed  2  sample  sample  with  Sullivan  2  weight  % reaction  of water  =  Chloride  time  = 40  minutes  g  1.296 .704  =  soluble  -509  strongly  FeS  2.000  weight  adhered  Sulphur  T = 113°C,  i n weight  Uncorrected Analysis  S C1 ,  g  C306 mg)  Reaction  Reactants:  Experiment  3  A large part of the insoluble residue to the magnetic s t i r r i n g b a r .  C-4  Pyrite  40.0 g  23.2%  Zn:  Scale  weight  Digestion:  Fe:  Large  weight  residue*  Analysis  101 -  704 —00~0~  x  1  products:  (vs.  ^y  0  0  =  3  5  «  2  %  Fe  (total)  Fe  (ferrous)  CI  (total)  f o r FeClg  =  0.523)  438  mg  5  mg  860  mg  -  C-5  Reaction of Metallic Reaction  Loss Analysis (see  of water  Observed  Only  C-6  a  40 wt  i n sample  section  fraction  with  40 wt  T = 133°C, S.SgCl  weight  soluble  .767  =  371  %  time  , iron  surface  (vs.  with  Conditions:  Reactants:  |y  10  sample  wt  T  S.S C1 2  =  20  film ' 5  1  Fe  (total)  33  mg  Fe  (ferrous)  32  mg  CI  (total)  43  =  2  on  .787)  the metal  Sulphur  Chloride  = 70°C,  time  2  2  weight  Residue weight before s a l t or w a t e r wash ( s e e s e c t i o n • 22 ) Resxdue weight after f i n a l wash  minutes  mg  remained  % S.S C1 ,  2  strip  for FeCl  of the product  Reaction of Galena  Initial  %  -  3.15)  =  Reaction  Iron  Conditions:  Reactants:  102  Pine  = 20  Point  1.000  g  1.018  g  surface  minutes  PbS  2  Analysis  Observed  of hot s a l t  —  =  2.85  wash  .891 g  solution:  (vs.  |y  Pb 94 (sulphate precipitation )  mg  CI (by  mg  for PbCl  33 difference)  2  =  2.92)  -  C-7  103  Reaction  of Chalcopyrite  Reaction  Conditions:  Reactants:  Initial Final Analysis  "Partly  sample  sample  o f water  Calculated Residue  40  present  as  with  40  T = 70°C,  % S.S C1 , 2  weight  wt  1.00Q  %  time  -10Q  2  weight  S.S C1 2  = 90  + 140  m  2  minutes Phoenix Chalcopyrite concentrate  g  0.208  soluble  Chlorine  Analysis  wt  -  products  required  f o r CuCl  Cu:  5  mg  Fe:'  47  mg  S  42  mg  :  magnetite  Cu:  272  mg  Fe:  245  mg  CI:  775  mg  £ FeCl  : 771  mg  Appendix D-l  D:  Selected Experimental  Reaction  Substrate  -200 + 270m Sullivan i te  ti II  it II  tt II  ti it ti II  tt it II  it -70 + 100m Sullivan Pyrite  of Pyrite  Time (minutes)  with  Results  40 wt  % S.S  CI  T(°C) Percent of [ l - ( l - R ) Pyrite Reacted  5 10  139.7  5 10 30 45 60  129 . 0  10 20 30 60  119 . 7  5 20 40 60  113 . 0  20 40 60  113 . 0  tt it ti ti it tt ti tt tt tt it  '  43 . 5 67.0  0 . 173 0 .309  19.8 37.5 81.7 96'. 4 98.5  0 . 071 0 .145 0 . 432 0 . 670 0 . 753  16 . 6 30.9 44. 3 75 . 0  0 .059 0 . 116 0 .177 0 .378  7.4 22.6 40 . 3 58.5  0 .025 0 .082 0 .158 0 .254  13 . 2 24. 9 35.3  0 . 046 0.091 0.135  1  ] r  [l-(l-R) ] ° (cm x 10 ) 1  5 . 41 9.56  Rate cm m i n x 10  -  1  4  Mean r a t e cm m i n x 10 -  4  1 .08 0 . 9 67_  1.02  2.22 4.54 13.5 21. 0 23.6  0 . 444~~ 0 . 454 0 . 45 0_  0 . 449  1.85 3.63 5.54 11. 6  0 . 18 5~~ 0 .182 0 .185 0 . 193_  0 . 186  0.78 2.57 4.95 7.95  0 . 15 6~ 0 . 129 0 .124 0 .133  4.07 8.04 11. 9  204 201 198  0.129  201  1  D-l  (continued)  Substrate  -70 + 100m Sullivan Pyrite  -70 + 100m Noranda Pyrite  -70 + 100m Sullivan Pyrit e  Time (minutes)  T(°C) Percent of [ 1 - ( 1 - R ) Pyrite Reacted  1 / 3  ]  r  [ l - ( l - R ) ° (cm x 10  1  /  3  ]  Rate Mean r a t e cm min " " cm m i n ~ l x 10 x 10 -  )  1  4  4  20 40 60  120 . 0  20 . 0 36.9 50 . 7  0.072 0 .142 0.210'  6 36 12 6 18 6  10 20 40  126 . 2  17 . 4 32 . 8 54.9  0.062 0.124 0.233  5 . 48 11. 0 20 . 6  0.548" 0.550 0 . 515_  0.538  10 20  133 . 0  28 . 0 46 .1  0 .104 0 . 186  9 .19 16 . 4  0. 9 1 ? 0 . 820_  .870  15 15  139 . 7  51 51,  Avg.=.215  19.0  1. 26  1.26  10 10  146 . 9  51 52  Avg.=.217  19 . 2  1.92  1.92  10 30 45  119 . 9  5. 3 14. 0 21. 9  0 . 018 0 . 049 0.079  1.59 4 .33 6.98  0 . 159 0 . 144 0.155  0 .153  10 20 40  119 . 9  10 . 4 20 . 3 37 . 7  0 .036 0.073 0 .146  3 . 18 6 . 45 12 . 9  it  ti  it it  . 318 . 315 . 310  318 323 323  . 314  .321  D-l  (continued)  Substrate  - 2 7 0 + 325m Sullivan Pyrite  it II  Time (minuted)  5 10 20 30  T(°C) Percent of [ l - ( l - R ) Pyrite Reacted  119  11.9 24 . 9 44 . 5 63.0  0 .041 0 .091 0.178 0.282  1  ] r  [l-(l-R) ° . (cm x 10  0.988 2 . 19 4 . 29 6 . 80  1  )  ]  Rate cm m i n x.10 4  0 0 0 0  .198 . 219 . 215 .227  -  1  Mean r a t e cm m i n . x 10 -  4  . 215  1  D-2 D-2.1  Reaction of Galena Experiments  Substrate  -150 + 200m Pine Point Galena  with  Without  Time (minutes)  10 wt  Added  %  S.S C1 2  Catalyst  T(°C) Percent of [ l - ( l - R ) Galena Reacted  10 20 30  60  5 10 20  70  5 5 10 10  80  5  90  II II  II II  ti II II  3. 0 5. 7 8. 5  ' ] r  [l-(l-R) ' ] Rate Mean ° cm min "*" (cm x 10 ) x 10 5  0.010 0.020 0.029  4.38 8 . 76 12 . 7  0.438 0.438 0.423.  2. 8 5. 6 11.2  0.009 0 . 019 0.039  3 . 94 8 . 32 17 .1  0.788 0.832 0 . 855_  5 .4 6 .5, 10 . ? 14.0.  Avg . 0.019  11. 0  Avg .0.043 0.038  rate  -  8 .32  1.66  18.8  1. 88  16 . 6  3.32  0 .433  825  1. 77  3. 32  D-2.2  Experiments  Substrate  - 1 5 0 + 200m Pine Point Galena  With  Time (minutes)  Added  Catalyst  T(°C) Percent of [ l - ( l - R ) Galena Reacted  10 20 30  30  5 10 15 20  40  5 10 15  50  5 10  60  ir it tl II It it tt ti  1/3 1/3 ' ] r_[l-(l-R) ' ] Rate ° ,, cm m i n (cm x 1 0 ) x 10 4  1  4  Mean r a t e cm m i n x 10 4  12 . 3 24 . 4 33.0  0.043 0.089 0.125  1. 88 3 . 90 5 . 48  0.188 0.195 0 .183_  0 .189  12 . 2 21. 6 30 . 2 44.0  0.042 0.078 0 .113 0 .176  1. 84 3 . 42 4.95 7 . 71  0 . 368 0.342 0.330 0.385  0.356  25 . 6 50.5 69.0  0.094 0 . 209 0.323  4.12 9 . 15 14.1  0 . 824" 0 . 915 0 . 940_  0.893  47 . 0 69.4  0 .191 0 . 326  8 . 37 14 . 3  1. 67 ~ 1.43  1.55  _  D-3  Reaction  Substrate  -100 + 140m Phoenix Chalcopyrite  of Chalcopyrite  Time (minutes)  T(°C)  5 10 20 30 45 60 80  50  5 10 20 30 45 60  60  5 10 15 20 30  70  5 10 15  80  ii it ii II II II  it it ii ii II  ti ii II II  II  it  with  40 wt  Percent of Chalcopyrite Reacted  % S.S  CI  Cl-(l-R)  1 7 3  ]  r  [1-(1-R)  1 / 3  o (cm  x 10  )  7. 2 11.4 19 . 7 28.4 34 . 7 43 . 9 52.7  0.025 0 . 040 0.071 0 . 105 0 .132 0 . 175 0 . 221  1.56 2 . 50 4 . 44 6. 56 8.25 10 . 9 • 13 . 8  12 . 20 . 34 . 44 . 57 . 66.9  4 7 4 3 4  0.043 0.074 0 .131. 0.177 0.248 0.308  2.69 4.63 8 .19 11.1 15 . 5 19 . 3  19 . 9 34.9 43.2 53 . 8 66.5  0.071 0.133 0 . 172 0.227 0.305  4. 8. 10 . 14 . 19 .  33.2 53.5 64 . 5  0 .126 0.225 0.292  7 . 88 14.1 18 . 3  44 31 8 2 1  -. J  D-4  Calculated  Screen Size Fraction -  70  + 100  Values  of r  o  G e o m e t r i c Mean Diameter (cm) mesh  r  o  (cm)  1.77  x 10~  2  8.85  x 10~  3  3  -100  + 140  "  1.25  x 10~  2  6.25  x 10~  -150  + 200  "  8.77  x 10~  3  4.38  x  -200  + 270  "  6.26  x 10  3.13  x 10~  -270  + 325  "  4.83  x 10~  2.41  x  _ 3  3  10  10  _ 3  3  _ 3  - Ill -  Appendix E :  Schematic Flowsheet  f o r Treatment  of P y r i t e w i t h Sulphur Chlo  FeS2 concentrate S-S2CI2  leaching  /1  >  sulphur crystallizer  sulphur product  f  liquid-solid separation  oxidation of FeCl3  O2 or  air  Fe20 & non-ferrous metal chlorides 3  metal chloride <solution ^ 2^3 P luct e  roc  ^  _ i  aqueous leach  -  Appendix F:  -  1 1 2  Schematic Flowsheet f o r P r o d u c t i o n o f Lead and Sulphur from Galena C o n c e n t r a t e .  PbS concentrate  SS CI  t  2  2  leaching  sulphur crystallizer ~ ~ r ~  sulphur product  PbCI ,FeS2,ZnS 2  4  hot H/NaCI leach  -> unreacted ZnS,FeS2,etc.  H/NaCI  PbC1  2  crystallizer  J  PbCI  2  eTe'cfrofy^s Pb  product  Cl  *  -  Appendix G:  113  -  C o r r o s i o n o f M e t a l s i n Sulphur  Chloride  In the course o f t h i s s t u d y , v a r i o u s m e t a l s were t e s t e d f o r r e a c t i v i t y towards Monel a l l o y  S2CI2.  (67% N i , 30% Cu, 1.5% Fe) i s known t o be r e s i s t a n t  to c h l o r i n a t i n g environments t h i c k ) was c u t and p o l i s h e d .  so a sample d i s c  ( 1 . 2 cm diameter x 0.4 cm  T h i s specimen was h e l d i n the s t a n d a r d  e x p e r i m e n t a l apparatus i n c o n t a c t w i t h 40 wt. % S . S 2 C I 2 f o r 18 hours a t 120°C.  The weight  o f the d i s c a f t e r t h i s treatment  (and the s t a n d a r d  wash sequence) was w i t h i n ± 0 . 1 mg o f the o r i g i n a l weight.  While  this  was n o t a d e f i n i t i v e c o r r o s i o n t e s t , i t i n d i c a t e s t h a t monel i s r e l a t i v e l y immune t o c o r r o s i o n i n a S . S 2 C I 2  environment.  T i t a n i u m m e t a l t u r n i n g s were c o n t a c t e d w i t h S 2 C I 2  i n a beaker  at room temperature.  No immediate  r e a c t i o n o c c u r r e d so t h e m i x t u r e  was warmed s l i g h t l y .  A f t e r a s h o r t time (^ 30 s e c o n d s ) , a v i o l e n t  r e a c t i o n o c c u r r e d and t h e m e t a l was c o m p l e t e l y consumed i n a few seconds  leaving only a small s o l i d residue.  similar  (but l e s s v i o l e n t ) way.  T i n shot r e a c t e d i n a  The absence o f s o l i d p r o d u c t s i n these  r e a c t i o n s i n d i c a t e s f o r m a t i o n of T i C l ^ and S n C l ^ - l i q u i d s which would be expected t o be m i s c i b l e w i t h S „ C 1 „ .  - 114 -  Appendix  K:  Calculated Solubility Ca)  2  and  2  8  (.Ideal)  using  Experimental Aten  solubility  t h e method  the data  after  zrys " i s  g  Calculated S C1  (b)  C a ) a n d E x p e r i m e n t a l l y D e t e r m i n e d (b) of Sulphur CS ) i n Sulphur Chloride.o f S„ i n 8  of Glasstone  (49)  o f Meyer ( 5 0 ) . solubility  (47).  See  of S  D  in  8 section  p(%3iow) A i n i a m o s  S.C1 2 2 1.322.  

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