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Show r The Story of Milling and Smelting at Midvale MidvaleI Midvaler I r . T ( ' p pA pt pr A t ; - r ' 11 / ASr tdfBY r + Aa 4 k utw rya Ytl Ytlk NM + a aZft Zft e eqf ' ' JL t tJ J , , qf . 1k 4 eels eelsJL ti I IA4 . , A4 * E i ie ir e II w I t r A A I fAj e ei i r hthd , a v 2 2o o fr aL A r ( r rtM tM ? b4t ' d e w f ; > " a * A N ; t tFr Fr I If f , : fr 0 ; . ' ' Ji : r'14,4 r144 r'14,4&F ' 4 : ; , &F F &F3rv & 3rv 3rvy 3rvtv y tv s yaa a aw aFlotation w Flotation is the process of separat ng the wheat from the chaff that s the valuable minerals from the thewaste waste In the Midvale Utah m II of the United States Smelting Ref ning and M n ng Company bat batter ter es of flotat on cells perform this interest ng process of I fting the heav er minerals to the surface surfaceand and leav the material at the bottom Ed ( ( Ed tor 0 a Note Th s a . s . s the third of a * aocr asec scr ocr sec w eo ea of f fv fve ve art rt clea cleo Iles on the .tory tory story . tory of o < m 11 11nlr 11ne UnK nlr ne andsmelt and , laielt smelt melt nic nil rig : of lead 100 1 lewd < z nc no ore at atM atat tM M at dnie dvale ) ) The pi pievious evlous article of o ( tills this ser es esmentioned esmentioned esmentioned mentioned the importance ot of the thedIscovery thediscovery thediscovery dIscovery and application ot of the thetlotatlon theflotation thenotation tlotatlon flotation process for ( or the recoveryot recotcryof recoery recotcry reco\ reco \ ery eryDt Dt of zinc previously prevloush previousll a penalty penally ele element element element ment in lead zinc sulphide oresThere ores oresThere There is romance in the evolu evolutlon evolutlon evolutlon tlon of o tlotat flotat flotatou 011 on It ' \ was as common commonknowledge commonknowledge commonknowledge knowledge that substances heavier heavierthan heavierthan heavierthan heavierthanwater than ' \ -water water - waterwould ater -would would - under certam certain certamsuitable certainsuitable certainsuitable suitable cond tons t ons ens float 1I0at on the wa water water water ter s surface tor for ( or exam example pie a II . greased greasedor or dry needle careully carefulIy carefully ( placed onwater onwater on onwater water It has he been en known hnown for ( or years yearsthat yearsthat yearsthat that some heav heavy ) ' substances will will1I0at willfloat willfloat 1I0at float with more certainty than thanothers thanothers thanothers others It Is reported that about about1885 1885 Carrie J Ivel : Eveison son a westen western westenlady westernlady westernlady , lady school teacher assisting asslstmg in her herbrother herbrother herbrothers brother s Denver assay offlce office dls dis dlscovered discovered discovered covered the main principles on onwhich onwhich onwhich which all subsequent notation 1I0tatlon flotation work workhas workhas workhas has been based basetl She had placed placedsome placedsome placedsome some greasy concentrate sacks In Inthe inthe inth the wash tub and with the stashing ' " washingore stashingore ashlng ashlngore ( ore bags are rarely if 1 ( ever washed washedny washedby washedoy ny by men ) the germ ot of o ( the idea ot of 011 oil 011tlotatlon oilflotation oilflotation tlotatlon flotation "came came oCame " under her observa observatlon observation observatlon observatlonModern tlon tion tlonModern tionModern Modern flotation 1I0tatlon Is a concentrat ins Ing process utlizing ut llzing IIzmg the buoyancyo buoyancyot buoyancyof buoyancy ot of ( air bubbles in 111 water to tloat float tloatm floatm floatm m neral particles partlcles Certain reagen reagents reagentsor ts tsor or Frothers are used to st shength stiengthen shengthen ! ength engthen en the bubbles thus form ng a astrong astrong astrong strong and persistent troth froth s mlhar miliar mlharto miliarto mlliarto to soap suds Other reagents known knownas as Collectors and Mod flers fiers liens I are areused areused areused used to condition the m neral par partlcIes partidies partides tlcIes tidies so that they will or will wl1l not notadhere notadhere notadhere adhere to the air bubbles This Thispermits Thispermits Thispermits permits selectivity in the tlotahon flotation flotationot tlotahonof flotationof of one or more minerals fiom flom from the themb.ture themixture themixture mb.ture mbture mixture . . ot of minerals as they occ oce occirin Ir it IrIn itin In natural oreThe ore oreThe The ore Irom from the company mmes mines mmesand minesand minesand and custom shippers received at atl.hdvale atMidvale atMidv&le atMidvle l.hdvale lhdvale Midvale . & Plant ot of United States StatesSmelting StatesSmelting StatesSmelting Smelting Refining Retlnmg and 1nlng Mning M 1\ 1 \ ! ning nlng com corn company cornpany cornpany pany is iswe -we we - ghed in railroad cars carsand carsand carsand and then goes to the sampling de department department department partment where ' in 'In Tn ace irate and andrepresentative andrepresentative andrepresentative representative small sample Is Isautomatically isautomatically isautomatically automatically taken The sample samplethus samplethus samplethus thus taken is " pround It"Tound ItTound ground to fine tine po powder powderand powderand " der derand and one part ot of o ( the sample goes to tothe tothe tothe the shipper Mi : Midi MhH ita1 al aJ " assay assa > ) of metal metaltontent metalcontent metalcontent tontent content determ nes flea hether the ore oregoes oregoes oregoes goes to the flotat tlotat jn In Ou m II 11 or d rec nec recto necto recto to the smelterAfter smelter smelterAfter After weighing and sampling the theore theore theore ore tor for the flotation tlotatlon null mill it is sent sentthrough sentthrough sentthrough grinding grindlug through a series of crushing crush.ing . grind Ing lug and regnnding regrmdlng regrinding units until final tlnal ly approx mately G5 GS'o GSo 65'0 650 G5o ' o ot of o ( the ore orepulp orepulp orepulp orepulpBill pulp \ -Bill Bill rill - III pass through a & wire mesh meshscreen meshscreen meshscreen screen having 40000 40 000 openings to tothe tothe tothe the square InchThls inchThis inch inchThis \This This \Thls Thls \ fine tine pulp reaches reaclJ.es reaclJes . the flota flotation flotatlon ota otatlon tlon tion machines " , where here with certain certainreagents certainreagents certainreagents reagents added the lead m nerals neralstloat neralsfloat ner&lsfloat nerlsfloat & tloat float wh Ie the other minerals mtnerals smk sink smkThe sinkThe sinkThe The lead float 1I0at ( concentrate ) Is Isskimmed isskimmed isskimmed skimmed off otf the surface surtace of ot theJiotatlon theflotation the theflotation Jiotatlon flotation flotation cells and the residue atter after atteradd afteradd afteradd add tion tlon of other chemicals goes to tothe tothe tothe the zinc flotation tlotatlon machines where wherethe wherethe wherethe the zinc zmc mineral mmeral floats tloals and is isskimmed isskimmed Isskimmed skimmed off oft as zinc concentrateOther concentrate concentrateOther Other concentrates conceutrates ot of lesser 1m fm 1mportance fmportance 1mportance portance are made as circumstances circumstanceswarrant circumstanceswarrant warrant \ \ arrant although it 1t is never pos Dos Dossable possible possible sible sable to recover all the m nerali nerals inan In Inan Inan an ore As in the case of ot the tloat float tloatIng floatlog floating Ing log needle having a dry or greased greasedsurtace greasedsurface greasedsurface surtace surface particles partlcles of ot ore attach attachthemselves attachthemselves attachthemselves themselves to air bubbles even be below below below low the surface of ot the water as asthese asthese asthese these bubbles are forced torced through throughthe throughthe throughthe the flotation machine machme cells celIs along alongwith alongwith alongwith with the chemicalsThe chemicalsThe chemicals chemicalsThe The flotation concentrates are aredewatered aredewatered aredewatered dewatered in 111 50 foot thickeners thlcheners and andmost andmost andmost most of ot the remaining remalnmg remainingwitter -witter witter water - is then thenremoved thenremoved thenremoved removed in niters filters after atter which thelead the thelead thelead lead concentrate concentrll.te concentrllte . is transported tra.nsported . to tothe tothe tothe the lead smelter and the zinc con concentrate concentrate concentrate centrate sh pped to a zinc ZIUC plant |
