UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Optimum conditions for the flotationa of sphalerite by iso amyl xanthate Harrison, T. Allan 1942-11-15

You don't seem to have a PDF reader installed, try download the pdf

Item Metadata

Download

Media
831-UBC_1942_A8 H2 O6.pdf [ 3.17MB ]
Metadata
JSON: 831-1.0062068.json
JSON-LD: 831-1.0062068-ld.json
RDF/XML (Pretty): 831-1.0062068-rdf.xml
RDF/JSON: 831-1.0062068-rdf.json
Turtle: 831-1.0062068-turtle.txt
N-Triples: 831-1.0062068-rdf-ntriples.txt
Original Record: 831-1.0062068-source.json
Full Text
831-1.0062068-fulltext.txt
Citation
831-1.0062068.ris

Full Text

OPT IHUM C OICOIEIOITS FOE SHE FLCffiAMGI 01? SPHALBBIf Til Bf . IS© A i l L submitted for olio decree of : MAS513H OF ARES' - • ' - w • • Department of •GhmrlstTj University of B r i t i s h ColraiMa 1948 I t i s . a t q t j great pleasure to aclmowledge the help and guidance of Br* W» Tfre®, xmH&T wkos© diasetioit, t h i s worli was eaa?3?ie& out* • Introduction l^QzlmCTtt^L. work - jlateriels Apparatus Flotation tests w i t t e t collector ELot&tion testa varjiag c o l l e c t o r f l o t a t i o n tests T&sfyitig pH Dec opposition of scant Iiate Effect of decomposition on c o l l e c t i o n Abstraction Discussion of abstraction results References . In esperiiaontal investigo.-!;ion of the f l o t a t i o n ox minerals* two teehniqtiQS are i n general use: the "contact angle" method as developed "by i?ark end Cox, and tiie* direct f l o t a t i o n mo tho a, i n which an expsr- iraontal c o l l i s rtscd, operating on the same principle &s those uoocl coiamereiallyc doing ths second method, the Dehaviotrc of -fotas- sinra othyl jtanthats as a col l e c t o r of sphalerite has "boon investigated i n t h i s 1 ah oratory for tho paot several '/oars. I t was desired,, hor/ever, to compile gos'-'O data as to the hohsviour of soma other collectors v/ith tho osse ore and under the sane conditions., i7ith this i n trim the present tvoid-i was iiridertalcen, using potassium iso-arayi stanthate as osseiople® general opinion seems to be that pure aphal- orlto v / i l l not f l o a t unless activated, Oaudind) how ever, states that with collectors containing an alky! Group of f i v s carbon3 or more, f l o t a t i o n i s posoihle v/lthcml; activation and submits data indicating that uit J i ranthates containing the ethyl, n-aciyl and n- hoptyl groups,, col loot ion of sphalerite increases i n that order. He also finds a groat variation of recovery of nnaetivated sphalerite at constant pli (S.S) v.nlnr; potaeolna n-exn^l saathat© at ooiiesiitratioBs ranging from soro to .6 Ib./ton r;ith a Bayissinvi of Ghent 46,J at ths l a t t e r . C«H«M» del Girl dice (2) quo-ces a»a sodorses §a«din.* Hoyass and Haas, to^he effect that using arayl xsatfcat©the aaslinaa recovery of ui i a c t i - vated sphalerite eomos i n the pE range from 3.4- to 5«4, but does not state what recovery v/as obtained» Swains©n and ^ndorson (3) however, express the b e l i e f that com paring various Kanthates as collectors, t h e i r a c t i v i t y reaches a Haxinran at four carbon atoms and that for any number of carbons, the secondary compound i s best, • followed by i s o - and noivial. Chair data era based on copper and lead ores however, not OH sphalerites i'/arls and Cox (4) express the view* based on t h e i r aeasursments of contact angles, that i n concen trations of S5Eg»/l«B iao-arayl scant hat© w i l l not f l o a t (inactivated sphalerite* In a l a t e r a r t i c l e (5) they state that i n higher concentrations (up to. 300 nig./ 1- J e or i n acid solution, ( c r i t i c a l pH 5.5), eon* tact i s possible*-, With regard to possible decomposition of the orayl xamtliste i n use, available fiata#6)„(?) indicato extensive decomposition of ethyl xanthate In eeicl solution* Similar behaviour on the part of the arayl Kanthate eould b© expected and was investigated i n the OO- jv 'GO of the motIc* Materials rp&Q different samples of o%& were used-*. A« Source: Pari: i n color sad when ground fine retained t h i s color- ffho esact composition was not determined, hut rough analysis indicated appr o:ci Kate 1 y 1 'I of copper i n the ore* 2Ms would, indicate that the ore was prohably activated,, at least p a r t i a l l y • 15* Source: Ottawa County, Olda* Dark colored when i n largo pieces 9 hut r/hen hroken up had a resinous ap pearance and when "ground fine was creamy white i n color. * J!o copper could he detected. Potassium 4so~sia;yl saethate was zaade hy the usual method iron C i-aioj/1 alcohol, carbon a i - oulphide and potassium hyftrozido. I t was diosolved i n Bcetoa®, c r y s t a l l i s e d twice from bensea©, dried and stored over sulphuric acid i n a desiccator* i'erplneol was used as frothor i n e l l toe to, a stock solution of 250 Mg./l, "being made up and amounts froia 10 to 25 u l . as reouiracl .v*ers placed i n tho c e l l along with the oro. Hie amount recjuired varied considerably with the pE at which the test was made, strongly haoic solutions requiring more t©j'pineoi.0 Apgarattig The ore was ground i n a laboratory P&WI& r a i l l with porcelain 2b,t ana, f l i n t pebbles* I t was sized i n an. e l u t r i a t o r as- described by Her&O).* the ore.having a s e t t l i n g rate between 8 and 16 cm* per aiirote being use a for a l l tests*- 2Ha s e l l used for f l o t a t i o n tests was a modification of the design by Sennet' a pyres f r i t t e d glass f i l t e r being sealed to'a piece of pyres tubing of the same diameter as the f i l t e r and SI os® long- A l i p v&& formed at the top of the tube to provide for an overflow* 9Jwo pli meters were used j an i n d u s t r i a l model Beoiinan with glass and ealorael electrodes f o r mD&surement of pH; and a research model Beclcnan with platinum and calomel electrodes i o r t i t r a t i o n s , f l o t a t i o n Tests I without Collector Gaudin (10} and Taggart, del Oividlee and iSionl 111), state that sphalerite has no native f l o a t - a b i l i t y , that i s * i t v^ .11 not fl o a t i n the presence of frother alone. In order to test the char a c t e r i s t i c s , of the c e l l and also the ore 6 both# ore samples \7©re tested by the following method* To a weighed* dry sample of the ore i n a beaker, about 200 ml. of water and 5 ml* of 81? ammonium acetate were added*' pii w»ts adjusted on the meter by additions of HOI or KOH as required* rfha water used i n .oil tects and o i l solutions throughout th i s Y/orlr was d i s t i l l e d , the only exception being e l u t r i a t i o n of the ore. flie 5 ammonium acetate iiras foti^fl necaosary sine© xrithout i t pH dr i f t e d considerably during the test-,, and p r e l i a i n - as^r tests indicated that i t had no. appreciable effect' on the f l o t a o i l i t y of the ore* Shis aistttgs was then placed i n the c e l l 9 10-8S ml« terpineol. were added ae needed and the volume t/as made up to 800 ml. A i r was turned on and adjusted to a pressure of 34 OBI, of mer cury, which pressure .seemed to work "beat wit& t h i s c e l l , • 5?he overflow was caught i n a bealcer and wben the froth had become clean, the overflow was f i l t e r e d tlirongli a weighed gooeh. crucible. She weight of heads was com pared the the sample weight to give a measure of the recovery obtained, expressed as per cent* . j^.arge maa- hsr of tests were made over a large pii range with ore A, the rc3P.lt3 of some of which are given i n Sable I* yhere i s no regular variation with pH noticeable« Also„ some factor not under control hae a large effect on the recovery at any one ol-U A simi l a r set of tests on Ore 3 gave an indication of regularity with pH, tliongii not enough tests were Hade to walre such a conclusion d e f i n i t e , Hesnlts of thSL set of tests are given i n Table 11 and Fig* 1*. ' 2A3LI3 1 Bscovery without co l l e c t o r - Osfa.fut pH sample weight •% recoverjr '•2,2 5.001 eg 1.16 2*7 5.000 4,00 3.6 6.001 5,30 4.5 S.004 §.84 4*5 • 5*001 8»1 -.5.5 1*000 »8 7*5 5*001 *74 9*0 S.000 - .06 5.0*9 5*000 1.2 Recovery without co l l e c t o r - Ors B pH . sample weight $ recovery 2.0' - g.00 18..4 4*0 &» .. 5*0 a&- S2#4 .6*0 -fie • 44*6 6*0 .. . to 0.5.*9 8*0 ' -do 18*5 10*0 _ dO' 17*2 '13*0 do 12*6 7 I I ' O o f f l J l ^ ^ ^ L ^ t & l ^ l a S , aaou-nts of cojj.ecto^r SMs .series of -teste was eondactefl only with Ors A* Procedure- was as outlined above, except, that just "before a i r was "blown into -the c e l l , a measured amount of a standardised.solution of the xanthate was added» i a -Tolumes corresponding to the amounts of c o l l e c t o r shows i s the table* fh©.volum© was 300 ft s i . * ' i s a l l oases*.- Basalts*' are shown fo r two complete series at p i 4 and 8*5 in'table I I I sad Irig* 2* .Also shoxfii are a few results obtained at ,pH..2*0 and 2*8 , 'though these series ar© not complete* As soon as a f r o t h head formed, when collection was good* th© froth became very heavily mineral!sed* Shis formed a heavy cafe© on top of the c e l l which had. .to he scraped off* f his behaviour was expected since i t had been B O B - t i o n s t as a characteristic of amyl xsiithat.e hy Saudis •{12} and Balston and Barfesr-flS}* . f Wzm$ tho curves-of f i g * 2.* i t i s -seen-, tnat l a f a i r l y acid .solution* the colleeto-r i s effective i n very small fU-autitiss,. shout 1 Big.* being a l l . that i s required to produce raaxiiaurg recovery*. In tho basic range however* .more colle c t o r i s required,, nearly -5 mg* "being reached- "before the -eurro levels off* 8. 2ABLE 111 Collection Of 0l*3 A'- varying amounts of collector pH sain pie 8.5 5..02 tag. coll... .5 heads si.2 pH sample 4.0 5*00 mg* c o l l , .1 heads 5..02 *5 44*2 .3 65.G 5*04 1.0 46*4 .5 81*5 5*00 1.5 51*6 2.0 92.5 3*0 58.2. £5.0 94.5 5*04 5*0 65*9'. 4,0 9S»0 • 5 * 0 4 4 * 0' §6*-@ 5*0 95.4 5:»00 4*0 78 *-6 . 2.6 5*00 .66 91*0 • 5,01 S.O ' 77.1 .70 9s*e 5.01 6*0 74*5 3„0 5,00 00*7 5.04 5*5 • 71*7 *SS 88*9 5*01' 7.0 7 4 . 0 I h i s series .was' carried' out on hoth ores*. The .collector was fixed at 5 rag. «ncf was added' iiamediately Before Mowing* i l l ' samples mm 5 grams* -Salils 1? and Pig*. B give the resuit8 phtained with ore A* i SABES XI • Collection of C varying p H pH recover^' pH recovery pH recovery x~:us 94.?? 88.0 9.5 g- 94.4 6.5 90-.5 10*5 60 c 8 o n 95^0 6.5 9.1 e 5 10.5 G8.2 4*5 94*4 94.0 7 0 5 01.4 89,7 i i . n i i ,f) 27,0 4*5 95.4 0.5 73.7 12.0 4.24 5® 5 91.8 9.5 76.0 12.5 1.79 5?J» following reeiilts for Ore 5 were ob tained during the work 011 abstraction (see "below). After treatment with the rsanthate solution, which was f i l t e r e d o f f , th© ore was oividedjlnto spproalraataly f i r e grara sample.?. About 800 ml. of water was adaed to each and the pK was adjncrtod to that required. 2'hio was placed i n the c e l l , ''terpineol added, the T O I I M S was made up to SOO l a l * and the c e l l woo blown. X!ha;a the froth had cleared, both heeds and t a i l s were collected i n weighed gooohes and the scrapie weight was obtained by addition of the two weight 9 » RJ?he f i r s t s i s results i n the •cable are preliminary teste made on welched samples and treated as shown, and indicated that -this variation i n teehiiiqite { pre- vj&shlng with santbate } has no appreciable effect on the f l o t a t i o n y i e l d . Basnlts i n Table V awti Fig.4* 10 EABO ' ?' Collection of ore B - varying pH pl-l v/ash pH o e l l sample heads yj treatment 5*0 5.000 4.974 99.5 5 Bg. collector i n o e l l 7.0 5*000 4.928 98.6 do 11 #0 • 5,000 4.695 do O » •J 3*0 .5*000 4.975 99.5 ' prswashed with 5 ag. c o l l . 7*0 5.000 4.957 99.3 do 11.0 11,0 5.000 4.750 95,0 do. 5-..0 5*0 G»607 6.447' 96*5 . f pr swashed wl t i i 20 rag. 5.0 5,0 5.0 15 »0 4»S64> ' 4*200 6.243 .98,5 ) ssnthate -20 fjy.oie do 5.0 5.0 S.999 S,367 99. g do 5*0 &j 0 5.3.3 5' Be IBS 98«8 do 5 ® 0 .' # 0 4,864 4.754 97.8 do 5«-0 7*0 5.48? 5.202 .95.0' do 5,0 7.0 5.717 5*520 do 8,0 8.0 •4.315 4*212 • y / * o do IS . 0 12 .0 •4.970 3.684 74.1 do 12.0 9,0 0*644 • 6.344' 9S:*4 do 13,0 5,000 3..7-42 74.8 5- mg» collector i n c e l l ...... 5*000 .441 8*8 do * Another va r i a t i o n t?as made possible Iry the above technique* I t w i l l ho noted that several of the samples were "blown i n tb©. c e l l ' at a different pH to that at which they were treated with santhate, tn.it that this treat-, - -- "v . • M ' — *<*—  O o - m  si :o - > 1  k o DC %n  • : > t «w :D - > 1  k o DC %n  • : > t Pi > C ID - o > • ••• « * \ 11 meat seomlmgly has no ©ffeetsince the results agree within the experimental l i m i t s with the results of nor mal treatment* Ehis would appear to indicate i n a rather definite' -manner that whatever the controlling effect of pH- i s , i t exercises•that control during tho reaction "between the collector and the ore, and not at the attaeb.- '. meat "of- the mineral to the. a i r bubble« SecoapositlOB of Santhate As. mentioned on page2r decomposition of the atayl "xanthat© was expected i n the acid range, Snsyefor© i t "was rather surprising to fi n d tte collector "behaving 'very e f f i c i e n t l y - as f a r up the pH scale as pH l»{?ig«5)» "She decomposition talcing place "was followed by a method simil a r to that applied to ethyl'rant hate by Keraper (?}• • Samples of rcanthate solution with oufxer added, were adjusted to the desired pH, allow©a to .atana f o r 10 •minutes, then returned to gH:6«i>f ??hich seemed to work h©st„ -and t i t r a t e d electrOmetrlcally with standard -iodine- solution®, She- results are shown i n Sable VI and i n gra^h'fonii i n figure 5* ' • IS • fABLS ?I Decomposition of Xauiiiate mg» Xantiaate yl. Oxl ge f i n a l decosip. 1*6 .0099 .0004 9&VQ 2,0. 0 ^ 0 - .0004 96.0 2 .0' .0108 ,00051 '•95. S .0108 .0005 8*5 ,0104 • .0005 95.2 2.75 ,0099 .0005 :94.8 .5.0 .0099 .0018 81*8 s.o .•0099 .0021 •' 2..25 ,0099 .0056 6So7 Si 5 ,0050? • .00508 . •39.2 3.9 *0099 - *O081 18.2 -4,5 *00507 -.00493 2.75 •5*0 -.0114. .0112 ' 1.75 S.5 .©0507 ,00507 6»0 ; .0114 ." •00507 .00507 v0114 *0114 — - *0105 -.0105 ——— 13*0 «01o8 *01O3 Bftgeofr of Peooapogltlon In an offers to f i n d some reason f o r the higli recovery l a v & t j strong aeicl ptilp9 ta© following var-" l a . • S - Of, ... , , , „ . „ )ecompo s /tion of > - a.myl X awtlia.t'e. Le ft** ' A A ; .: ' 9e\ t • ' i , , . , . O : ; • • i • i y- '\J\J i f : — i \ . . . •• ...... . iations oa? f l o t a t i o n teehnig.ii© were introduced. 10 ml* { 5 iag») of the collect or were diluted to about 200 ml. s teffer was added and pH adjusted -as required. Shis Eiisctnre was allowed to stand for 10 iainntes, after which i t was poured onto the ore sample i n the c e l l * Serpinsol as added and the o e l l was blown, ffihis proaediirs., since i t allows the collec t o r to decompose aa ••determined above before i t comes in' contact wtih th © ore. should result i n a diminution of recovery, provided the prod- nets of decomposition are inactive as c o l l e c t o r s . A •few tests were made with axayl alcohol i n concentrations l i k e l y to be found,* with no collection rasttlting* and carbon disnlphids i n small amounts has no co l l e c t i n g ' • action* .It w i l l be seen from Sable • T i l .(a,b,e)» that t h i s Is the case, indicating-that any other possible products of decomposition have very little„ I f any, effect*. Bierefore . j , .the high, c o l l e c t i o n i n the strong acid rangej as Indicated on Pig,. ge. aiiat be due to the action of. the zaathate ' i t s e l f , Shorn f o r compasses atlve•purposes,• imowing the amount of teeospoaition {trow F i g * 5)* another few tests were made -adding the "effective", amount of co l l e c t o r present i n the above tests.' 2he.se are shown i n fable T i l {&,e)• She c o l * l e c t o r was added immediately before blowing the o e l l . 14 ¥11 Sffeet of decomposition on r e c o v e r pH 2.5 S.O 'S.5 a. Collector added (jug.)- 5.0 5*0 5.0 o. Eff e c t i v e -collector .225 1.0 8-7 e. Collection {#) 1* 6.08 39.9 • 92.S 2. 4.5 S7.2 a. Collector added _ .225 1-.0 2*7 ©. Collection (fl} 12*5 S9.8 88*6 At ta© sarao time another few tests war© made i n which the ore and c o l l e c t o r mid water were allowed to stand at a definite pB. f o r ton minutes "before a i r was admitted* Ehe rosnlte of two aneh testa wer© 94*6 at pE S and 93*7 ;f at gS 3*5* ihat i s , aliening santhat© to stand for ten minutes i n acid pE i n the proaenee of tho ors results •- i n only a very slight reduction^of recovery, .nowhere near that to he exp©eto& i f ths santliato were aooou- posecU Apparently, then, the ©rs coating, Br^pna'bly sine aayl scant hate is' formed ana remains, regardless of the pH* Ahj3tra^ion In view of the faot that potassium l»amyl santhate lias "been shmn to he d e f i n i t e l y effective "in f l o a t i n g hoth# samples of sphalerite used,, an .attempt was Baa© to show that the ore ttai».strseteart the c o l l e c t o r from solution. In the following worlc one sample B was used entirely* Previous attempts have bean made In th i s lab oratory to measure abstraction with sphalerite and ethyl scauthate with no success{14).9 the d i f f i c u l t y being one of t i t r a t i o n of the residual 2nanthate9 She general procedure followed wao to s t i r the ore with an eiccesa of sant.hate. i n solution for 10 rain, at the. required pH* fhe l i q u i d was then f i l t e r e d off the ore and attempts were made to fi n d either the amount of scant hate remaining on the ore or the amount remain ing In the l i q u i d * P i l t r a t l o n s ware performed with the arrangement described by Semper C7)-,9 except that the f i l t e r used wao a pyres f r i t t e d glass funnel of 10 cm* diameter* Several variations of'procedure were t r i e d as' outlined below* 1« She- f i l t r a t e was t i t r a t e d electroiaetrieally with standard iodine solutions . ffihis method, as found by other workers.,, gave results much too high, indicating either no abstraetica.,'or Indicating saore'reducing material i n the f i l t r a t e than had been placed there o r i g i n a l l y i n the form of .^anthato* She end-point was not good, the potential tending t o ' d r i f t badly, making the t i t r a t i o n very tedious and not very accurate. 2* .She f i l t r a t e was t i t r a t e d with iodine an before but using starch as Indicator* 'Shis gave high results also, and had the further -disadvantage that the d.isan%fe 16 thogen forced •o'bseured the "bin® starch color. S. Elie d r i f t i n g of potential in(l«) above seemed to indicate that tlx© reaction causing the interference was a slov? one. This .suggested the p o s s i b i l i t y of b-ack- t i t r a t i o n , carried out ciuicM.y, to remove the effect. M s was t r i e d by adding an excess of the iodine s o l  ution to-the f i l t r a t e and then 'bads-titrating with either sodium thiosnlphate or soSlitm arsenate,, again using starch indicator near the end-point, Ehls, however, gave a very poor endpoint.s the "blue color returning for'about f i v e minutes after i t hafi "been f i r s t reiaovod.s Atterapts were made - to standardise the end- point (such as. remaining clear after 2 ininntes) "trat t h i s vras not 'dependable* 4« She next l i n o of attack was to remove the scant hat® from tho ore and t i t r a t e i t . . After tho orig i n a l san- thate solution had 'boon removed., the ore was s t i r r e d f o r 45 laiiiutes i n acetone.. Tim acetone was than f i l % tered off,, diluted with water and t i t r a t e d . Using starch,- the acetone was.found to decolorize tho starch iodine coisples, while electroxaetriealiy, the acetone caused the potential to d r i f t so "badly that an accurate end-point was- impossible * Even after most of the acet one hod been removed by evaporation nnder a vacumm , these effects remained* 5* I t was noted that when sine amjrl saint hate was formed by addition of sine chloride to potassium• aayl" Kant bate solution, i t redissolved on addition of SOH*•' Shis suggested the po s s i b i l i t y • t h a t the ere coating eould. be d i s s o l v ^ i n 1C0H and thon the rasulting ^solution, t i t r a t e d . So t h i s end an ore sample,, after treatment with 2-anthate solution was washed thoroughly and thon s t i r r e d for giaours i n 2H KOH* Baylor and Knoll (6) state that under such conditions there i s esttsnslBe decomposition of xantfaate ion. One sample of san.tfe.ate solution was t i t r a t e d after being i n 2 1 KOH for S hours* /.It showed a decomposition of 6 !ps which could eas i l y be allowed f o r i n calculation of abstraction. . She WB solution was neutralized and t i t r a t e d , and after correction by a blank t i t r a t i o n , gave a result Indicating some abstraction* However as a eheMs on the refnoval of the coatings some of the or® was*- placed In the c e l l with, water and terpineol and blown* I t was found to f l o a t just as well, .as I t did before the KOH treatment* • Shis was taken as an Indication that the coating had not been removed* •Further indication of the permanence of the coating was obtained i n . an attempt to reclaim some x:anthate treated ore f o r further use* This ore was s t i r r e d for 10 hours In "2 IS EDI, after which I t was washed, thoroughly el u t r i a t e d and dried* A sample was .then placed In the o e l l with frother but no co l l e c t o r , when It was found.to f l o a t approximately 40 $ at pH 11. rlie characteristic flocculated appearance of the pulp was-••no ted, indicating that the floa t i n g was probably not just the result of cleaning* -fheoe results seemed to indicate that reiaoval of the rauihate layer, at any rate Quantitatively, was not p r a c t i c a l * I t was then decided to return to a% wore indirect t i t r a t i o n met hod• 6» SJayior and ICnoll(6) have given a method used by the-a i n a study of abstraction of ethyl Xanthate by galena* Since this was the pethod used to obtain the results "below i t i s given in d e t a i l . A weighed sample.of sized ore was placed i n a beater* a Imovm, amount of semth&t© solution was added* and after the addition of a few drops of atamontra?} acetate buffer, pH waa adjusted to that desired* Che aisrfrare ( t o t a l volume about ISO ml*.) was then s t i r r e d by motor for ten aiimtes. Ehe rant hate was Measured, by volume of a solution which had been standardised by an iodine™ starch titration.. At the end of the ten minute period, the l i q u i d was removed by suction i n the apparatus referred to abovo( -7)„ fhe ore. was washed with about 100 nil. of d i s t i l l e d , water and was then sucked as dry aa possible» She f i l t r a t e , which was perfectly clear, was diluted to 500 nil* i n a volumetric f l a s k . 100 a l . portions were taken by pipette and treated as follows: . ,; (a) t i t r a t e d as* i t was with standard iodine solution* 19 Co), a c i d i f i e d (pH 5) and extracted with S ,?0 »iU portions of toluene* Shis treatment ' remove ,e a l l santhate ae santhie acid (aolnhle i n toluene)» -She water solution remaining was then'titrated a f t e r neut r a l i s a t i o n * She volume of iodine tins obtained was subtracted from that obtained i n (a) as a correction for reducing substances present^othen than santhate* gho resulting corrected volume '' was used to calculate tho santhate remaining in solution and thus gave a measure'of the abstraction which had taken place* In the. f i r s t t r i a l of this net hoc!, two more 100 ml* portions of the f i l t r a t e were treated as above except that t i t r a t i o n wao done ei e e t r o a s t r i e a l i y . S i t r a t ion of .Cb)f was very unsatisfaotory and e n t i r e l y undefendable„* She reason was not determined- I t was also found "that' by using very,dilute iodine f -about -*3 grams per l i t e r ) and by adding,, as -.reeonmended by Eaylor and S a o l l , 5 a l * - of\. a ".5 K] solution of potas sium sulphate solution, a very exact ©'Mr-point 'eonld bo obtained using potato starch* {lot'soluble starch,)• Dilution of the 100 ml, portion of f i l t r a t e '-to about S00 Klv before titration-, so reduced the density of the d i ~ xanthogen foraed i n the t i t r a t i o n that i t s opalescent blue color dies not interfere with' the end- point blue* .Eesults obtained by this' method are shown i n Table f i l l below* A l l at pH 6-.0 2 0 3&BEB T i l l .Abstraction of 1-arayl.santhate by sphalerite (3) fest i!io 0 Or© At* Xanthate In Original P i n a l lag, Abstr. Abstraction mg./gr.-ors. 14 9*562 19*64 15.10 4*54 *475 15 | 347S 80*48 18 .02 2*46 . ,£80 16 4,70S 2S*S0 21,05' 2,25 *477 17 25.,SO 21 ..68 • 1,62 aS01 Averags -.408 fosts no» 1 - 1 3 were those uaed In methods 1 to 5 described'' above. One test, (Al8) was nan at pH 12*5 Instead of pH 6 with the result that an abstraction of *237 rao/gr. was foancU Alio reason for choosing these two values f o r pH'trill he found i n Pigs, 4 and 5 ...- pi! 6 1B well In the range of xnaadtacsa f l o t a t i o n , r/lrile i t Is not acid enough to cause decomposition* . At pH 13.5 recovery has dropped off sharply*One would expect „ then, less abstraction at pH 12*5* ffhls expectation Is borne out i n the results • above9. though In view of the. wide variation In results at pH 6, -one value at 12*5 cannot be considered conclusive.* Discussion of •abstraction results Fallowing the method applied by Herd (8) to galena, the- calculations below were Bade* Prom Stoltes Lsw9 using the average rate-of s e t t l i n g of the- particles as 12 cm. par minute, the average radius i s calculated to be 1»75 x 10 em* To check t h i s , a microscopic measure ment of SiO particles was made, giving the frequency curve shown, i n P i g . 6«4. where one square unit equals 256. square BJU. Calculation • of average area and radius frora the frequency table by a method due to l'hurstone(15) -S ,gave a value of 1,73 x 10 era. Area per etfoic centimeter of parti c l e s i s given "by the r e l a t i o n Z Area' equals volume x 0 as 1715 squ.ora. r Eaking the density of sphalerite as 4 gia./oe* gives the area per gram of 4-28*7 squ. osu Holaenlar volume of 97*38 .' -3S sine snlphide™m'^^^^ - 4.o4 ac 10 e.e. -8 Holecular' diameter then is S.4S x 10 . The number of Eiolecnleo per SQU»' cm* area, then Is 1 3*43 x 10 15 s *8S 2. 10 » She number of senthate ions then required • • 15- for a unimoleeular layer i s 1 ?7jgAlQ___ .. from Sable T i l l , , average abstract ion Iter gra® of ore i s •408 ag«. f i l l s corresponds to 23 , .18' •408 x 6*03 s 10 - 1.22 z 10 xanthate Ions* .202 2C 10 1'hese are spread over an area of 428*7 S Q U . era. fhe number of santhate ions per square era* then i s 18 15 ~J^?u-&-10~- = 2.84 s 10" . / ! O O D ~**™*~««*^**^^ ) oo • I t i s thus seen that the nuaber of nanthote ions abstracted i s suff i c i e n t to form a layer between one and two molecules thick. She calculations of area are .probably largely i n error, since the sphalerite particles' are estreiaely irregular i n shape, but the above result 'would seem to indicate a definite layer formation. SOTSAHY • 1. Behaviour of two different samples, of sphalerite with potassium iso amyl scant hate has been in v e s t i g  ated, both with oonoentratipn of collector and pH as variables •> 2® She decomposition of potassium iso ©ayl scant hate has been investigated. 3* Evidence i s presented concerning the behaviour of the senthate as a collector i n strongly acid: solution 4. i'he problem of abstraction has been investigated- and some results obtained* . • 11SP131HCS3 1. Gandl'n, "Flotation" p-204 MoGraw K i l l eo« 1932 2. 6.1.IUS©! Gttidie©, Eng., and Min* Jnl * p S58e 1935 5* Swainson and Anderson, Trans* "Sleet roehem. Soe* 60,S29,S1. 4* dark and Coz, A*I.M.I. 112,189,1954 5. ffavfc and Cos, A.I.M.B., 112§267, 1934 6. Saylor and l i o i r A j a l . S . 112, 582, 1954. 7. Kemper, 3*A* Thesis U.B.C'1940 8. Herd, M.A. S&esis, U.B.C. 1940 9. Bonnet M.A.Se. ffihesis JBB.C 1938 10. Candin, op*.eit. .p 37, 11. raggart, del Gnidioe, and iJeihl, A.l.M.B. 112, MB, 19g4. 12.. Saudln, op.oit. p IIS* 13. Balaton and Barker, Erans. .lleetroehea.. Soo. 60, 319, SI. 14. Hawkes, B.A.Shesis, TJ..B.G. 1940 15 e fhnrstone, "fnndaaentals. of S t a t i s t i c s " , quoted i n Stroud, "iMueationai .Psychology" p 73. 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0062068/manifest

Comment

Related Items