Sulphide deposits—their origin and processing PDF
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Sulphide deposits-their origin and processing Sulphide deposits-their origin and processing Editorial Committee: P.M.]. Gray, G.]. Bowyer, J.E Castle, D.J. Vaughan and N.A. Warner ~) I n~~ The Institution of ~U~UU Mining and Metallurgy I Published at the office of ~ The Institution of Mining and Metallurgy 44 Portland Place London W1 England ISBN-13:978-94-010-6851-2 e-ISBN-13:978-94-009-0809-3 DOl:10.1007/978-94-009-0809-3 © The Institution of Mining and Metallurgy 1990 Frontcover isafalsecolourbackscatterelectronimage,obtained from CamecaCamebaxelectronmicroprobe,showing colloformcopper sulphides from CattleGrid orebody,Ml. Gunson, SouthAustralia.Photograph kindly supplied byA.R.RamsdenandD.H. French,CSIRO Division ofExploration Geoscience,Australia Foreword Thesulphide depositspose achallenge to every technology thatthe mineral exploitation industry uses. Their structure, composition and multi-elementcontentcould hardly befurtherfrom thoseof the end-productsof highly refined singlemetals which mustbewon from them.The location ofthe deposits israrelyon the surface,close to end-productmarkets,andthe disposalof the by-products of processinginenvironmentally acceptable waysisanunavoidable part of processing.The mining of sulphide depositsisprobably more expensive per tonne of productthanfor anyotherof the tonnage metalssincelow unit costmining methods cannot be usedin deep veinsor lodes or,ifthe sulphidesarein disseminated form,the depositsareof low grade. Research engineersand scientistsarestrivingto relate, inusablescientific terms,the propertiesof thesenaturaldepositsto thephysicaland mechanical meansof transformingadeposit into anengineering material. The quantitative characterization of mineral textures hasadvanced considerably inrecent yearswith the advent ofmore powerful equipment. Itisnow possible to identify all mineralspresentinanybut the very finestof microstructures, measurethe proportions of eachpresentand obtain anaccurateandfull analysisof allthe elements contained inthem. Evenwith thesemeasurementswe arestillsome wayfrom being ableto forecastthe reaction of anaturalcombination of sulphide andganguemineralsto, for example, the application of mechanical forcessuchasareusedin oregrinding,the rates of reaction in contact with anaqueoussolution of well-defined and homogeneouscharacteristicsor the behaviourof discrete particles ofthattexture when subjected to gravity,magnetic or surfaceforcesin mineral separation. Thisgapinrational understanding isnot too comfortable for the processengineer to live with and, evenifhe hasgrown accustomed to itin dealing with mineral feed, it is,nevertheless,possiblystillatitswidest indealing with the sulphides. Production engineersareaccustomed to organizing their data,andthustheir manufacturing technology, into rigid programs which cantakecommand of day-to-day operation almosttotally. Itisasalutaryexperience for amineralprocessingengineer to observe amodern motor-caror electronic componentproduction line and realize how farhestillisfrom understandingthe basicparametersthat stillgive him some unwelcomesurprises- not infrequentlyatfive o'clockon aSundaymorning! Thisvolume recordssome of the progressthat hasbeen achieved recently inunderstanding the processesbywhich sulphide mineralshavebeen assembledby natureandthe wayinwhich the propertiesof those assemblages influencethe metallurgical processesthat havebeen derived bytrial and error on abulkscaleto treatsulphides.There isstill farto go. Greatadvancesinthe technologies of medicine, electronics,telecommunicationsand dataprocessinghavefollowed from research into the fundamentals of the most basicmolecular, atomicandelectron units.Perhapsbasicresearchinto the fundamental forcesthathaveformed the Earth'scrustwill, intime,provide metallurgistswith the right tools for transforming mineralsto metalson acontrolled production line basis. Meanwhile, the 'try-it-and-see' methods on the production or pilot plant andinthe laboratoryusedby metallurgistsfor the sulphidesarebecoming more sophisticated and efficient. Thefuture for the major non-ferrous metalsand alltheir many associatedelements from the sulphide depositsisbright. The challengeto matchthe productquality and price demanded bythe userisno lessthan it everwas. PhilipGray TechnicalEditor July, 1990 Contents Page Page Foreword v Methods of recovering platinum-group metalsfrom Stillwater Complex ore Geology,petrology andmineralogy E.G. Baglin 155 China'ssulphide deposits - their Compositional and textural variations of the occurrence and treatment major iron and base-metal sulphide minerals 165 YuXingyuan, LiFenglou and Huang Kaiguo JamesR.Craigand DavidJ.Vaughan Isflotation the unavoidable way for RioTinto deposits - geology and geological beneficiating metal sulphide ores? models for their exploration and ore-reserve J.De Cuyperand Ch. Lucion 177 evaluation F. Garcia Palomero 17 Concentrate processing andtailings disposal Improved model for design of industrial The massivesulphide deposit of Aznalc6l1ar, column flotation circuits in sulphide Spain, Iberian Pyrite Belt: review of geology applications and mineralogy loseflna Sierra 37 R.A.Alford 189 Comparison of methods of gold and silver Precious-and base-metal mineralogy of the extraction from Hellyer pyrite and lead-zinc Hellyer volcanogenic massivesulphide flotation middlings deposit, northwest Tasmania - astudy by D.W. Bilston et al. 207 electron microprobe A.R. Ramsden etal. 49 Variablesin the shearflocculation of galena T.V. Subrahmanyam et al. 223 Mineralogy and petrology of the lead-zinc- Roleof chloride hydrometallurgy in copper sulphide ores of the Viburnum processing of complex (massive)sulphide Trend, southeastMissouri, U.S.A.,with ores special emphasison the mineralogy and D.N.Collinsand D.S. Flett 233 extraction problems connected with cobalt and nickel Evaluationof the CANMET FerricChloride Richard D. Hagni 73 lead (FCl) processfor treatment of complex base-metal sulphide ores Oreprocessing andmineralogy w.j.S.Craigen etal. 255 Principles and practice of sulphide mineral lead production from high-grade galena flotation concentrates by ferric chloride leaching and R. Herrera-Urbina et al. 87 molten-salt electrolysis l.E. Murphyand M.M. Wong 271 Chelating reagentsfor flotation of sulphide Mercury production from sulphide minerals A. Marabini and M.Barbaro 103 concentrates by cupric chloride leaching and aqueous electrolysis l.E. Murphy, H.G. Henry and l.A. Eisele 283 Mineralogy of and potential beneficiation processfor the Molai complex sulphide Arsenic fixation and tailings disposal in orebody, Greece METBA's gold project M.Grossou-Valta et al. 119 M.Stefanakisand A. Kontopoulos 289 Studiesof mineral liberation performance in Acid mine drainage from sulphide ore sulphide comminution circuits deposits D.M. Weedon, L]. Napier-Munn and CL, Evans 135 Fiona M. Doyle 301 Geology, petrology and mineralogy Compositional and textural variations of the major iron and base-metal sulphide minerals James R. Craig D~p~,!ment ofGeologicalSciences, Virginia Polytechnic Institute andStateUniversity, Blacksburg, Virginia, U.S.A. DavidJ.Vaughan Department ofGeology, The University ofManchester, Manchester, England ABSTRACf ore deposits. Thesemineralsrangefromsulphidesinwhich the ~rincipal metal extracted is a necessary, and usually The crystal structures, stoichiometries, electrical and dO~lna.nt, c~nstituent(e.g., galena or sphalerite) to sul magneticproperties,stabilitiesand mineraltexturesfoundin phides In which the most valued metal is a minor to trace the metalsulphidesare brieflyreviewed. Eightofthe major ~onstituent(e.g., goldinpyriteorarsenopyrite). Sphalerite iron and base metal sulphide minerals, chosen because of ISan excellentexampleofa sulphidethat serves in both of theirwidespreadoccurrence (pyrite, pyrrhotite),role as the the ways notedabove; itis minedfor its zinc content but it majororemineralofaparticularmetal (chalcopyrite, spha virtua~ly is today the only sourceofcadmium, an eiement lerite,galena,pentlandite),or importanceas acarrierofrare present as a minor to trace component. It also serves as a or preciousmetals (arsenopyrite,tetrahedrite) arediscussed sourceofgallium,germaniumandindium. Itisimportantto in greaterdetail. Thecrystalstructuresand physicalproper rememberthat the ~ulphideminerals,especiallypyrite,have ties ofthese mineralsare discussed, along with phaserela also ~erved as maJ~r sources ofsulphur (and more rarely tions in the relevantsulphide systems. Particularemphasis seleniumand tellunum) aswell asmetals. A generallisting is placed on the presentation ofdata on major and minor ?fthe majortypes ofsulphide-richoredeposits,aspresented elementcompositionalvariationsinthese mineralsand textu inTable2,documentsthe abundanceofthese mineralsinthe ral features commonly observed in ores containing them, ore~. Inaddition,.these majorsulphideminerals,especially both ofwhichareofcrucialimportanceintheirmetallurgical pynteandpyrrhotite,occuras common accessoryphasesin processing. alarge varietyofrocktypes. Thesesameminerals,so valuableasmetal sourcesor as INTRODUCflON hosts to the minerals that contain the metals,aretoday also The naturallyoccurring metal-sulphurcompounds,col recognizedas the potential sourcesofmajorenvironmental lectivelyreferredto asthe sulphideore minerals,serveboth hazards,suchasacid minedrainageand acid rain. The min as actual metal sources and as the hosts for many of the eralofgreatestcboenccaeurns~in this regard is pyrite also known world's precious, base and strategic metals. Distinct, as "fool's.gold," ofits very superficiisimilarityto named, sulphide species now number in the hundreds and ~oldand ItSa~undantWIdespreadoccurrence. Indeed,pyrite ISoverwhelminglythe mostabundantmetal sulphidein the have beenvariouslyclassifiedon the basisofchemistryand crust ofthe earth. Its content in sulphide ores may range crystalstructure. Despitethis largegroup, mostcompletely listed in Fleischer(1987), the majority ofsulphide-bearing from only a few pe~cent ofth~ sulphid~mass in Sudbury type and somestratiformmassivesulphidedeposits, to vir deposits are dominantly composed ofone or more of the tually 100%ofthe sulphidemineralsincoal beds. small group ofmajor sulphide minerals listed in Table 1. This listingofonly eightmineralsisadmittedlyarbitrary,but these mineralsconstitutemorethan 95% (and inmanycases . The compositional variations of the major sulphide 99%)ofthe sulphidemineralvolumein mostsulphide-type minerals are reasonably well characterized, both as aresult ofnumerousanalysesofnatural samplesfrom awide variety Table 1. The majoriron and base-metalsulfideminerals. Ideal PrincipalElementsDerived Name Formula (* by-product) pyrite(marcasite) FeS2 Co, Au, S pyrrhotite Fel_xS Ni, S* chalcopyrite CuFeS2 Cu sphalerite ZnS Zn, Cd*, Ge*,Ga*, In* galena PbS Pb, Ag*, Bi*, Sb* arsenopyrite FeAsS As,Au tetrahedrite CU12Sb4S13 Cu, Sb, Ag, As pentlandite (Fe,Ni)9Sg Ni, Co, Pd* 1 Table2. Abbreviatedlistingofthemajortypesofsulfideoredeposits. This classificationismodifiedandmuch simplifiedfrom thatofCox and Singer(1987). Type MajorMinerals" MetalsExtracted Examples Ores related to maficandultramaficinttllsions Sudburynickel-copper po, pn, py, cpy, viol Ni, Cu, Co, PGM Sudbury,Ontario Merenskyreefplatinum po, pn, cpy Ni, Cu,PGM Merensky Reef, S.Af. 1MReef,Montana Oresrelated tofelsicinttllsive rocks Tin and tunsten skarns py, cass,sph, cpy, Sn, W Pine Creek, California wolf Zinc-leadskarns py, sph, go Zn,Pb BanBan,Australia Copperskarns py,cpy Cu,Au CarrFork,Utah PorphyrycopperI py, cpy, bn,mbd CU,Mo,Au BinghamCanyon,Utah molybdenum Climax,Colorado Polymetallicveins py,cpy,go,sph,ttd CamsellRiver, NWT Oresrelated tomarine maficeXttllsiverocks Cyprus-typemassive py, cpy Cu Cyprus sulfides Besshi-typemassive py, cpy, sph, go CU,Pb,Zn Japan sulfides Oresrelatedtosubaerial felsictomaficextrusiverocks ~e-typeepithermal py, sph, gn, cpy, ttd, Cu, Pb, Zn, Ag,Au Creede,Colorado vems asp Almadenmercury type py, cinn Hg Almaden,Spain Oresrelated tomarine felsictomaficextrusive rocks Kurokotype py, cpy, gn, sph, asp, Cu, Pb, Zn, Ag, Au Japan ttd Ores inclastic sedimentaryrocks Quartzpebble py, uran, Au Au, U Witwatersrand, S.Af. conglomerategold- uranium Sandstone-hostedlead- py, sph, go Zn, Pb, Cd Laisvall,Sweden zinc Sedimentaryexhalative py, sph, gn, cpy, asp, Cu, Pb, Zn, Au, Ag Sullivan,BC lead-zinc (Sedex) ttd, po Tynagh,Ireland Ores inCarbonaterocks MississippiValley type Py, go, sph Zn, Pb, Cd, Ga, Ge SEMissouri • Abbreviations used as follows: po=pyrrhotite,pn =pentlandite,py =pyrite.cpy =chalcopyrite. viol = vio\arite, cass=cassiterite.sph=sphalerite. wolf=wolframite, go=galena.bn=bornite,mbd=molybdenite, ttd=tetrahedrite,asp=arsenopyrite,cinn=cinnabar,uran=uraninite. ofdeposits, and as aresultofsystematiclaboratoryinvesti- ion probe and the proton probe (PIXE), have yielded new gationsofthe phaseequilibria. We can here onlypresenta datathatappeartogivemuch moreaccurate measurementsof few relevantphasediagrams; for additionalinformationthe the sulphidemineralcompositions,especiallyfor minorand readerisreferredtoBartonand Skinner(1979) and Vaughan traceelements. Table3presentsa listingofthe maximum and Craig(1978,1990). Table3containsatabulationofthe contentsofmany elementsinthemajorsulphidesconsidered maximumconcentrationsofnumerouselementsinthe com- inthispaper. Sourcesused were limitedto those employing mon sulphideminerals. Analyticaldata for thecommonsul- modem analytical techniques that should have largely phidemineralsis abundantbut widelyscatteredand largely avoidedcontaminationbymineral inclusions. redundant in displaying minoramountsofavariety ofele- ments. The large number of analyses results from these mineralsbeingabundantandfrom thedesireofinvestigators STRUcruRESANDPROPERTIESOFTIlEMAJOR to ascertain the distributionofvaluedelementsso that they SULPHIDEMINERALS can beeffectivelyextracted. Therehave been relativelyfew extensive compilations ofsulphide mineral compositional Cxystalstructures ranges. The largest (Fleischer, 1955) is now 35 years old and containsdataderivedprimarilyusing analyticalmethods Severalofthe common sulphide minerals were among that indiscriminatelyincludedelementsfrom mineralinclu the first materials to be studied by X-ray crystallography, sionsaswell asfrom the mineral beingstudied. Thedevel andsincethattime thestructures ofnearly allmineralogically opmentoftheelectronmicroprobe,which allowsanalysis of significantsulphideshave beendetermined. Itispossibleto areas as small as a few micrometers, and morerecently the categorizethemineralsulphidesintoaseries ofgroups based 2 on majorstructuretypes,or havingkeystructuralfeatures in are also, commonly, other minerals that have structures cOrJ?11lon,as shownin Table4 (modifiedafterVaughanand basedon these "parent"structuresandthatcan bethoughtof Craig, 1978). In manycases,theseare the classicstructures as being "derived" from them. Therelationship betweena of crystalline solids such as the rocksalt structure of the derivativestructureand theparentstructuremay involve: galenagroup(Fig. lA), the sphaleriteand wurtziteforms of ZnS (Fig. IB,C),orthe nickelarsenidestructure(Fig. lC). (I) Ordered substitution, e.g., the structure of chal Thedisulphidesare characterizedbythe presenceofdianion copyrite (CuFeS2)is derived from sphalerite(ZnS) (S-S, S-As,As-As,etc.)unitsin the structure;as well as the by alternatereplacementofZn atoms byCu and Fe pyritestructureinwhichFeS6 octahedralunits sharecomers resulting in an enlarged (tetragonal) unit cell (see along the c-axis direction, there is the marcasite form of Fig. 2A). As also shown in Figure 2A, stannite FeS2 in which octahedra share edges to form chains of (Cu2FeSnS4) results from furtherordered substitu linkedoctahedraalong the c-axis (Fig. 10). Thestructures tionofhalfofthe Fe atomsinCuFeS2bySn. ofFeAs2(loellingite)and FeAsS (arsenopyrite)are variants ofthe marcasitestructurethathave,respectively, shorteror (2) A stuffedderivative,e.g., talnakhite(Cu9Fe8S16)is alternate long and short metal-metal distances across the derived from chalcopyrite by the occupation of sharedoctahedraledge(seeFig. ID). A few sulphidessuch additional, normalIyemptycavitiesin the structure as molybdeniteorcovellite (Fig. IF) have layerstructures, (Fig.2B). and a smallnumberexhibit structuresbestcharacterizedas containing rings or chains of linked atoms (e.g., realgar, (3) Ordered omission, e.g., monoclinic pyrrhotite AsS). Adiversegroupofsulphides,referredtobyVaughan (Fe7S8) isderivedfrom the NiAs structuredFeS by and Craig(1978)as the metal-excessgroup,iscomposedof removal ofFe atoms leaving holes (vacancies) that an unusual and diverse set ofstructures well illustrated by are ordered (Fig. 2C). the important example of the mineral pentlandite «Ni,Fe)9S8, see Fig. 10). (4) Distortion,e.g., the troiliteform ofFeS is simplya distortion ofthe parent NiAs structure form (Fig. As can be seenfromTable4, in manyofthesegroupsa 2C). numberofmineralssharethe actualstructuretype, but there Table3. Maximumconcentratio-ns(hippmunless otherwiseindicated)ofnumerouselementsintheeightmajorsulfide minerals discussedinthetext Alldata arefrom studiesemployingtechniquessuchaselectronmicroprobeorPIXE thatare both sensitiveand capableofavoidingcontaminationbymineralinclusions. Referencesfor thedataare given inparentheses afterthedata: Full referencesaregivenattheendoftext. Element pyrite pyrrhotite chalcopyrite sphalerite galena arsenopyrite pentlandite tetrahedriteSS V 32 (11) Cr 11(11) Mn 11.69% (17) 158 (3) 5.7% (I) Fe essential essential essential 27.6% (17) essential essential 13.6% (29) Co majorss 415 (3) 9.9% (33) 52.6% (20) 4.2% (8) Ni majorss 719(3) 0.21% (24) 4.3% (33) essential 3.5% (8) Cu 40 (11) essential 1.3% (26) 2000(26) essential Zn 3334(5) 2570(4) essential 1.19% (26) 12.7% (8) Ga 0.16% (14) Ge 0.14% (14) 1.3% (28) As 8% (9) essential 30.1% (8) Se 644 (3) 180 (3) 4383(5) 396(3) 3681 (3) 682 (4) 41.1% (13) 'h 37(11) - Mo 7(10) 0.8% (28) Ru 80 (4) Rh 5200(4) 86 (4) Pd - 1.42% (4) Ag 0.12% (5) 1685 (3) 1.62% (19) 308 (5) 3.1% (10) 14.77% (27) 55.0% (22) Cd 2.84% (7) 899 (3) 11.9% (23) In 1085 (5) 10.4% (31) - Sn 0.41% (5) 2.34% (15) 286 (3) 7(10) 14% (8) Sb 900(24) 7900(24) 37.1% (8) Te 200(10) 26.4% (18) W Pt Au 110 (30) 1.8 (30) 7.7 (30) 3.4 (30) 1.6% (25) 2.26% (32) Hg 17(11) 24% (8) rt 400(10) 2.6% (28) Pb 51 (11) 0.38% (26) essential 6.3% (24) Bi 0.58% (24) 6.2% (10) 19.7% (2) References (1) Basu(1984) (2) Boldryeva(1973) (3) Brill(1989) (4) Cabri(1984) (5) Cabri(1985) (6) Cabri(1989) (7) Craig(1983) (8) DoeIter(1926) (9) Fleet(1989) (10) Foord(1989) (11) Fralick(1989) (12) Harris(1984) (13) Johan(1982) (14) JOOan(1988) (15) Kase(1987) (16) Kieft(1990) (17) Kissin(1986) (18) Kovalenker(1986) (19) Loucks(1988) (20) Misra(1973) (21) Nikitin(1929) (22) Paar(1978) (23) Pattrlck(1985) (24) Pearson(1988) (25) Picot(1987) (26) Scheubel(1988) (27) Scott(1973) (28) Spiridonov(1988) (29) Godorikov(1973) (30) Cook(1990) (31) Burke(1980) (32) Kovalenker(1980) (33) Klemm(1965) 3 Table 4. Sulfide structural groups. 1) THE DISULFIDEGROUP PyriteStructure MarcasiteStructure ArsenopyriteStructure Loellin2iteStructure FeS2pyrite \FeS2marcasite FeAsSarsenopyrite FeAs2loellingite COS2cattierite! FeSbSgudmundite CoAS2safflorite NiAs2rammelsbergite derived byAs/Sordered substitution (Co,Fe)AsS cobaltite (Ni,Co,Fe)AsS gersdorffite (I) 2) THEGALENA GROUP PbSgalena a-MnS alabandite 3) THE SPHALERITEGROUP SphaleriteStructure .. derived byordered substitution- stuffedderivatives B-ZnSsphalerite CuFeS2chalcopyrite Cu9FegS16talnakhite CdShawleyite CU2FeSnS4stannite CU9Fe9S16mooihoekite Hg(S,Se) metacinnabar CU2ZnSnS4kesterite CU4FeSSghaycockite 4) THEWURTZITEGROUP WurtziteStrucmre .. composite structurederivatives- ?furtherderivatives a-ZnS wurtzite CUFe2S3cubanite CU2Fe2SnS6hexastannite CdSgreenockite ?AgFe2S3argentopyrite derived byordered substitution CU3AsS4enargite 5) THE NICKEL ARSENIDEGROUP NiAsStructure .. distortedderivatives .. orderedommissionderivatives NiAsniccolite FeStroilite Fe7Sgmonoclinic pyrrhotite NiSbbreithauptite CoAsmodderite Fe9SlO,Fell S12hexagonal pyrrhotite, etc.? 6) THETHIOSPINELGROUP C03S4linnaeite FeNi2S4violarite CuC02S4carrollite 7) THE LAYER SULFIDES GROUP MolybdeniteStructure Tetragonal PbOStructure CovelliteStructure MoS2molybdenite (Fe,Co,Ni,Cr,Cu)l+xS CUScovellite WS2tungstenite mackinawite -Cu3FeS4 idaite 8) METAL EXCESSGROUP PentlanditeStructure ArgentiteStructure ChalcociteStructure (Ni,Fe)9Sgpentlandite Ag2Sargentite CU2Schalcocite C09Sgcobaltpentlandite ""?derivative CU1.96S djurleite DigeniteStructure---...derived byorderedsubstitution CU9SS digenite CU7S4anilite NickelSulfideStructures NiSmillerite Ni3S2heazlewoodite 9) RING OR CHAIN STRUCTUREGROUP StibniteStructure RealgarStructure CinnabarStructure Sb2S3stibnite AS4S4realgar HgScinnabar Bi2S3bismuthinite Insome cases, therelationships involvedaremorecom amples ofordered omission mentionedabove) toregard the plex, as,for example, incertain of the sulphosaltminerals" mineral sulphide structures as a relatively "rigid" sulphur where the resulting structure is composite and made upof lattice framework fromwhich metal atomscan beremoved, slabsorunitsofaparentstructure(orstructures) arrangedin ortowhichmetalatomsmaybeadded. some ordered fashion (animportant exampleofasulphosalt mineral, tetrahedrite, isfurther discussed below). Itis also Stoichiometty usefulincertain cases (suchasthestuffedderivatives orex- Many metal sulphides show evidencethat theelements that comprise them are not combined in a simple whole numberratios, i.e.,theyexhibit non-stoichiometty. • Defined as minerals with a general formula AmTnXp in In certain cases, the extent ofdeviation from a simple which common elements are A:Ag.CuPb; T:As,Sb,Bi; X:S. They ratio is considerable. For example, the pyrrhotites are containpyramidalTS3groupsinthestructure. 4
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