The object of the following tests was rather to determine quantitatively the consumption of Potassium Cyanide and of Sodium Cyanide when agitated by compressed air, and when agitated by compressed air in the presence of iron pyrite and in the presence of iron filings, than to explain chemically the causes for this consumption --Part One, page 1.  The following tests were made to study the rate of percolation of water, under certain conditions, through pure quartz. the information sought is of importance in the cyanide process. By  rate of percolation  we mean the distance traveled in a unit time, by water through a bed of quartz or other ore. In all of our experiments no suction was used --Part Two, page 14

Caples, Russell B.

Schmidt, Sidney S.

English

Missouri University of Science and Technology (Missouri S&T): Scholars' Mine

Scholars' Mine Bachelors Theses Student Theses and Dissertations 1910 A study of some problems in cyaniding Sidney S. Schmidt Russell B. Caples Follow this and additional works at: https://scholarsmine.mst.edu/bachelors_theses  Part of the Physical Sciences and Mathematics Commons Department: Recommended Citation Schmidt, Sidney S. and Caples, Russell B., "A study of some problems in cyaniding" (1910). Bachelors Theses. 8. https://scholarsmine.mst.edu/bachelors_theses/8 This Thesis - Open Access is brought to you for free and open access by Scholars' Mine. It has been accepted for inclusion in Bachelors Theses by an authorized administrator of Scholars' Mine. This work is protected by U. S. Copyright Law. Unauthorized use including reproduction for redistribution requires the permission of the copyright holder. For more information, please contact scholarsmine@mst.edu. THI~SISfor the Degree ofBachelor of Sci~nc~.1910.-r2-1A STlrJY OF ~)O];J.;~ PHOBLi}]J;S IN CYANIDING.bySidney S. Schmidt.10915Russell B. Caples, Jr.PART 1.CYANIDE i~ND OF SODIUM CYANIDA IN DILUTESOLUTION ,E! A.GIT.lTION lSrr'H COLlPRRSSED.1IR \.A.l~D BY ./lGITArION ·.~;ITH COMPH3SSl;;JO}' IRON PYRIT3lU~D OF IRON FILINGS.P.iU1T 2.p.meo I..J.~T IONOF ',";,ATER THROUGH ?URE \~LJ.AllTZ OJ? VARIOUSBYSIDNEY S. SG:'"!MIDTf\ f 'f! D\)~qlD~ ~tf.TA.BL~~ OF CONT=mTS.SUBJECT.Part 1.BibliogTsphy.Met_od of Prooedure.T••t N111iber Ont ;-The d.t ermination of the 108. of KONand NaCN when agitated in dilutesolution by compressed air.Test Number Two;-The ••termination of the 10s8 of KCNand ~JaCN when agitated in dilutesolution by compressed air in thepre••noe of iron filings.T••t Number Thr•• ;-The d.termination of the loss of KCNand NaCN when agitated in dilutesoluti on by compressed air in thepr•••noe of pure iron pyrite.PAGES.1-14.2.3-6.6-B.8-10.10-12.T~~LE OF CONTENTS. (aont'd)C'UBJ"7CT,) . .:... ...Part 1.Tilt Number Fonr;-Th. d.tlrmination of the loss of KONaDd laaN when agi tat.d in dilutelolution by compre...d ~ir in thepres.no. of iron pyrite and one halfof one percent of iron filings.Pari 2.Bibliocraphy.S.ri•• Gne:-~t study 0 f the rat. of the downwardp.roolation of water throu~h sizedquartz.Seri•• Two,-1 study of the rate of the downwardperoolation of water through mixedeiz•• of quartz.Conolusioll..PAGES.12-14.14-2C.1'7-19.14-1'.14-17.19-20.PART ONE.The object of the following tests was rather todetermine quanitatively the consumption of PotassiumCyanide and of Sodium Cyanide when agitated by compressedair. and when agitated by compressed air in thepresence of iron pyrite and in the presence of ironfilings, than to expla.in chemically theca-uses for thisconsumption.~e have attempted to determine the amounts ofcyanide oonsumed by the various substances, compressedair.iron pyrite and iron filings, and also to findout under what conditions the consumption was greate8t.. SuchThe literature, containingAinformation on cyaniding,is exceedingly meagre.-1-BIBLIOGRAPHY.The following references constitute practicallythe whole bibliography:Julian and Smart.Cyanidation of Concentrates.(Very little is given onthis subject by these authors, and no definiteconolusions are drawn, neither is any reliable datagiven) •Julian and Smart.Solubility of ~yrite and Cast iron in KON. Both pyriteand cast iron are sli,htly soluble in KON solution,the decree of solubility increasing- with the strencthof KeN solution used.In our tests we did not find this to be thecase. The solutions were tested with I Fe ON and4 6KeNS, but no trace of iron was indicated.-2-MErHOD OF PROCEDURE.We attem:pted to conduct all of the tests underas nearly similar oonditions as possible. In orderthat no outside chemical agents should be present. toaffect the results -.all of the apparatus used in thetests was of glass. The tanks were conical in shapeand had a capacity of about ten litres each. In orderto insure a perfect agitation and a thorough seriationof the solution various schemes were tried. The onefinally adopted was that of installing a miniatureair pump as shown in the accompanying illustration.The central glass tube is one half inch in diameter,and held in position by being passed through a glassIring which holds it in a vertioal .position.Compressedair i~ snpplied by a one eighth inch glass tube. which•conducts the air to the bottom of the central tube.The agita~ing apparatus is really a small Brown orPaahuca tank. This method furnishea good agitationand aeriation. In order that the amount of air suppliedto each tank should be the same: a T joint was insortedin the hose carryin~ the air t and the tanks oonnected-3-to this T joint and the air was admitted under thesame head of water. The air supply in the hose wascontrolled by a needle TaITe which enabled us toeasily regulate the air supply.All of the tests were run at a constanttemperature. Each test was run for ten hours.The cyanide salts used were; chemically purepotassium cyanide .and chemically pure sodium cyanide.During the course of the test., samples weretaken at the end of each hour, by means of a graduat adpipette. Each of the samples from all of the testswas titrated arainst the same solution of silver nitratewhich contained 6.538 (rams of chemically pure silvernitrate per litre. One c.c. of the silver nitratesoluti on equals 0.00500 &rami KeN ani 0.0037'1 gramsNaCN according to the reactions:AcN03+2KCN-KAiCN2+KN03AiNO +2NaCN-NaA.eCN +NaNO3 2 3But 8S all of the samples were titrated against thesame solutions the results are comparative s.nyway,so the above preoautions are somewhat unnecessary.Adsorption ~ooses by filter paper in filtoriDi. were-4-undetectable, experiments with solutions of KON andNaCN of known strength, after passing one, two andthree filters, showing no discernable loss.Evaporation losses were corrected for by addingdistilled water before takinr- the hourly sample; theamount to be added being shown by a scale pasted onth e outside of the glass, the height of the solutionbeing marked at the beginning of each hour and thetank filled to this mark before taking the samples'-\" The -e no{ \? f rh ~ h. 0 u .... ,-5-TEST NUMBER ONE.This test was run to determine the losses ofpotassium cyanide and sodium cyanide, When agitatedby oompressed air. No solids were present. In onetank was placed five thousand o.c. of potassiumcyanide solution. Which contained 22.75 grams KeNor 0.455%, and into the other, five thousand c.c.of sodium cyanide. which contained 22.05 grams ofNaCN or 0.441%. The amounts of KCN and NaCN weredetermined b~t analysis of th e solutions, and not byconsidering the cyanide salt s used pure KON and pureNaCN. Agitation was started at 1.10 P.M. and ?Ontinuedfor tan hours. 'FifT,y ".-;) c.e. samples were remOvedat the end of each hour and titrated to determinethe loss of cyanide.The full results of this test are contained intables 1 and 2. From th ese tables and th e curves, itwill be seen that the greatest lOBS took place duringthe first hour of the test • .llso that the peroontapconsampt ion of KON was nearly twice thAt of the NaCN.Although a variation of the losses during the last ninehours is shown, they art not enou£ib. to materially-6-affect the value of the experiments and can probalbybest be accounted for by the variable evaporationlosses. for which we corrected by adding distilledwater and then agi tat ing for a minut e to insure agood mixture.The average 10s5 per holtt of KON during thelast nine hours is 0.191 grams. The loss durin~the ninth hour at a variance with the general trendof losses.In conclusion; the results show that the maximumloss ocours during; th e first hour, and that from thenon the hourly loss diminishes. From this test itwould seem that losses due to agi tat ion by compressedair, are greater for .KCN than for NaCN.-7-TEST NUlm3R T~VO.In this test, the oondi tions.: as to the amountof air supplied. temperature, and strength of solutions,\Vere practically the same as for test number one.Five thousand c.c. of solution, assaying O.50Q%KeN} were plaoed in one tank. and five thousand c. c.of solution, assayin~ O.50~~ NaCN, in the other.Agitation '.vas sta.rted and then 500 gTams of cleaniron filings, that had been pas.sed through an 80 mesh,were added to each tank. Fifty c.c. samples weretaken at th e end of each hour and assayed. The resultsof these tests are given in tables 3,4.9and 10, andin the accompanying curvets. The ~eate.t loss ofcyanide occurred during the first hour I and from thenon diminishes.No soluble iron was found to be present. Testsfor acidity were made but no acid was found. Thetotal losses for these tests ware not much ~eaterthan in test number 1. In this test, as in thepreceding one, the loss of KON exceeded the loss ofNaCN. The net 108988 by iron filinp are shown. intables 9 and 10.The losses by aeriation in test 1, are subtractedfrom the losses in test 2. The presence of 500 gramsof filin.o-s, caused a total loss in ten hours, oftill ,he1.098 grams or 4.4%, oIj..total potassium cyanide~and of 1.754 grams or 6.~. of the total sodiumcyanide.Tho loss of sodium cyanide. although leiS bothin the presence aDd absence of iron filings, than theloss of potassium cyanide, is greater due to the actionof iron filings alone.-9-The oonditione as to amunt of air supplied,temperature and .tr.~h of solutions~ were praoticallythe same for this te.t as for the preoeding onas. Fivethou8and c.o. of solution, &ssayin,O.485%,potassiumcyanide, cd five thousand 0.0. of solution, assayingO.46~ sodium oyanid., ware used. Samples were takenas before.,~ .Agitat ion was started, and to each tank wasadd&d 1500 &:rams of iron pyrite. wh ich had b.n passedthrough a 100 mesh screen. The purite was unsized butW~Qall"through 100 mesh. and contained about on. half ofone percent metallic iron, derive. from the mill usedin grinding. Some trouble was encountered in filtering,as the finlly diTid.d pyrite persisted in coming thruthe filt,r•• although "White Ribbon" filters wereused. The cloudiness of the filtrate was removed bydiluti~ the sample to b' titrated. to one hundredand fifty c.c. before titration, thus allowilli theend point to b. easily d.teoted.The results of ihis te.t are ciT" in tables5.6.9,10 and in the aceo~anJiDg curve8.1e.ta for acidity were made, 8O.dshowed no free-10-acid at any time during the test, or at its conclusion.The consumption of potassium cyanide was greaterthan for the sodium cyanide, as in the previoustests.-11-TEST NUJMBER FOUR.In this test. the condi t ions as to amount ofair supplied, temperature, and streneth of solutionswere praotically the same as in the previous tests.Five thousand a.c. of solution, assaying 0.468 j~potassium cyanide, was pla.oed in one tank. and fivethousand Q. c. of solut ion, assayin~ 0.435% sod.iumcyanide in the other. Agitation was start.d and thenone thousand ~ams of iron pyrite added, from whichthe iron filings, derived in grinding, had been removedby means of a strong magnet. The pyrite was unsized,but all passed af'on. "hundred-mesh screen.The greatest 1088 occurred during the firsthour. The potassium cyanide aeain suffered the greaterloss.In the potassium cyanide solution the total lossdue to pyrite when using fifteen hundred grams ofpyrite,under our conditions, is 12.724 grams of KeN,~" t't '" reD Ju ,.,. 1"1.which is nearly a gTaIn more than two-thirds of l7.802~A otlA..p~e..9.The loss is then somewhat proportional to the amount,J ..Jof pyrite used.In conclusion:Agitation by compressed air,results in a consumption of cyanide, the loss being-12-greatest durin~ the first hour. and then ~adually(hourly) diminishing to a nearly constant loa.Potassium cyanide suffers a. ueater loss than do assodium cyanide. Losles due to the presenee of finelydivided partioles of metallic iron, are very small,and praotically ne{:ligable. Losses due to the presenceof iron pyrii., are lar~f the greatest loss occurringin the first hour.More exper iments along th is line are greatlyneeded, but lack of time has prevented our takingthem up.-13-PART ·TWO.The following tests were made to study the rateof percolation of water, undar certain conditions,through pure quartz.The information BOUBPt is ofimportanoe in the cyanide .prooess. By "ra.te of percolat ion"we mean the distance travelled in a unit time, by waterQr~",Clrorethrou~h a. bed of quartz~ In all of our experiments nosuction was used.The data obtained is given in the aocompanyingtables. The curves art plotted from these tables• .Alltime _s taken wi th a stop watch. The gla.ss tubini'was three inches inside dis.meter. and in seven feetlengths. All the quartz was carefully sized and quitefree from dust. In order to bet ter follow the liquid.through the quartz, the water was colored with potassiumpermanganate or wi th ordinary washing bluing. Neitherooloring agent was at all satisfactory, as the solutionlost its color rapidly, in passing througoh the columnof quartz. The quartz particles seemed to extract thecoloring salt from the liquid. In the case of thepermanganate. the first coloring agent used,we decided-14-that the loss of color was due to ferrous irondissolved from the ~artz, but when the bluing solutionalso lost its 00 lor f we decided" that probalily adsorpt ionplayed an import ant part.Drainae;e was never complete, the last six inchesof ore never draining dry. The head was kept const8ntat six inches above the top of the ore until the~vat er came through the screen at the bottom, whenth is head was a11owod to subside. The time of drainageincl udes time of subsidence of the head. The wat ercame down very evenly, the center traTellinr equallyas fast as the outside," as was ascertained by glasstubes at the bottom.It will be noticed that the percolation throughthe dr~ quartz was uniformly faster than thron&h thewet quartz, and that the percolation uniformly becameslower with the number of times the test was run onthe wet quartz.1J.l of the tests numbered 2 on thewet quartz, show a slower rate than the first test,and all tests numbered three, show a slower rate thanthose numbered 2. A. curve of the a~.raga of the threewet tests wasplot"ted, but we believe that tha results-15-"of number three are more valuable, as they would morenearly represent the comditions in actual practice,where the ore had been crushed wet.It was noticed that, in the tests on the wetore, air was forced out of the bottom under considerablepressure, as the water percolated do~.vnward.-16-BIBLIOGRAPHY.The followin£ referencas constitute practicallythe whole bibliography:Juli8Jl and Smrj.Percolation is affected by;I.Volume and uniformitv of interstices.\\'2." .~~"The great.r the,.J)ercentage of interstices andthe more unifo~ the interstices, the fasterthe peroolat ion.2.Depth of or••The shorter the column, the faster will be the ctv,q, rft 1~ r ..r. of'percolation.3.Pressur••An increase in head ~iv.s an increase in therat. of p6rcolation~ but this increase in rat.'of peroolation is small in comparison to theincrease in head required to produce it •. 4.Temperature.The rate of percolation increases with thetemperature of the solution.5. Dir.otion.-17-Upward percolation is faster than downwardpercolation. This applies especially for ashort column of ore.No definite reasons were given for these~~~yconclusions~bsing largely taken from data obtainedfrom experiments.-18-CONCLUSIONS.·The eonc1usions we arrived at from the studyof percolation, under the various conditions statei.are as follows.The rat. of percolat ion of water throuch quartzis dependent upon the space in the quartz oolumnthat is occupied by air t therefore the rate of plr-colation is dependent upon the fineness of ~indini,far the perc8utap of interstic•• dearease. with thefineness of ~inding. In the teats on ooars. griniine-.or ooarSer size. of quartz, the time of subaidenceof tho aix inch head of water. was nearly the samefor the time of pas.ace of the solution through:.foot of quarts. ehowuae the .,.C8 occupied by airto b~ approximat.l,. equal to the apaae occupied byquartz. In the test. on finereizes of quartz thetime of subsidence of the six inch head increasedwith the fineness of the quartz particles, showinrthat the percentag-e of the interst ices deer...... withthe fineness of the quartz part iells. By ref. in~ tothe tabulat.d data, th& peroeniag'8 of interstices forany test can bo obtaine4 by dividin~ the average time-19-..t :t'8. ,f.f p !'calq.,0, t Jl'tof th'is iUI-2

A study of some problems in cyaniding

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A study of some problems in cyaniding

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