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Refractory gold ores in Archaean greenstones,Western Australia: mineralogy, gold paragenesis, metallurgical characterization and classification

Published online by Cambridge University Press:  05 July 2018

J. P. Vaughan  and
A. Kyin
J. P. Vaughan*
Affiliation:
Western Australian School of Mines, Curtin University of Technology, Bentley Campus, P.O.Box U1987, Bentley, 6845, Western Australia
A. Kyin
Affiliation:
Western Australian School of Mines, Curtin University of Technology, Bentley Campus, P.O.Box U1987, Bentley, 6845, Western Australia
*
*E-mail: [email protected]
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Abstract

Mesothermal gold ores in the Archaean Yilgarn Craton of Western Australia are dominated by a pyrite ± arsenopyrite ± pyrrhotite sulphide assemblage. Many of these ores are refractory to varying degrees and require treatment by roasting, bacterial oxidation or finer milling. The most common sulphide ore types can be sub-divided broadly into pyritic (pyrite±pyrrhotite) and arsenical types (pyrite+arsenopyrite± pyrrhotite). Arsenical ores vary from highly refractory to free-milling. Arsenopyrite in highly refractory ores is finer grained, As-deficient (27 –32.5 at.% As), contains high average concentrations of submicroscopic gold (60 –270 ppm), but does not contain inclusions of particulate gold. Arsenopyrite in free-milling ores is coarser grained, less As-deficient to slightly As-rich (30 –35 at.% As), contains low or negligible concentrations of submicroscopic gold, but contains inclusions and fracture fillings of particulate gold. In some refractory arsenical ores, pyrite also contains moderately high levels of submicroscopic gold (20 –40 ppm), the concentration of which is directly related to As content of the pyrite.

Pyritic ores are free-milling to mildly refractory, or rarely moderately refractory. Pyrite in pyritic ores contains negligible to low levels of submicroscopic gold (<5 ppm). Other reasons for refractory behaviour in pyritic ores include very fine-grained native gold inclusions in pyrite, or the presence of gold-bearing tellurides.

It is concluded that submicroscopic gold is incorporated into the crystal lattices of arsenopyite and arsenical pyrite at sub-greenschist to lower greenschist-facies temperatures, and is progressively expelled as inclusions and fracture fillings of native gold in sulphides, and ultimately into the gangue, as recrystallization proceeds through upper greenschist- into amphibolite-facies temperatures, during deformation and burial. Submicroscopic gold is expelled more rapidly from pyrite than arsenopyrite.

Pyrrhotite progressively replaces primary pyrite at higher temperatures, but rarely contains gold. Finally, a metallurgical classification scheme for refractory ores is presented which incorporates the above mineralogical conclusions.

Keywords

gold oresArchaean greenstonesmetallurgyWestern Australia
Type
Research Article
Information
Mineralogical Magazine , Volume 68 , Issue 2 , April 2004 , pp. 255 - 277
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2004

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References

Alexander, P., Henley, R.W. and Kavanagh, M.E. (1991) Mineralization styles and geochemistry in the Paddy's Flat Gold District, Meekatharra. Western Australia. Pp. 295–304 in: World Gold ‘91, The Australasian Institute of Mining and Metallurgy, Melbourne, Australia.Google Scholar
Archibald, F.R. (1949) Roasting arsenical gold ores and concentrates. Canadian Mining and Metallurgical Bulletin, 42, 129–139. 460–461.Google Scholar
Baciga lupo-Rose, S.J. (1992) Mineral ogy and Processing Characteristics of Selected Arsenical Gold Ores. MAppSc Thesis, Curtin University of Technology, 142 pp.Google Scholar
Barnicoat, A.C., Fare, R.J., Groves, D.I. and McNaughton, N.J. (1991) Synmetamorphic lode gold deposits in high-grade Archaean settings. Geology, 19, 921–924.2.3.CO;2>CrossRefGoogle Scholar
Brabham, G.R. and Johnson, N. (1995) Marvel Loch gold mine. Pp. 81–84 in: Southern Cross Greenstone Belt Geology and Gold Mines (Schwebel, P.J., editor). Geoconferences WA, Nedlands, Western Australia.Google Scholar
Bürg, G.H. (1930) Die sichtbarmachung des feinverteilten goldes in gold-hoffingen erzen und ihre wirtschaftliche bedeutung. Metallurgie Und Erz, 27, 333–338.Google Scholar
Cabri, L.J. and Chryssoulis, S.L. (1990) Advanced methods of trace-element microbeam analyses. Pp. 341–377 in: Advanced Microscopic Studies of Ore Minerals (Jambor, J.L. and Vaughan, D.J., editors). Mineralogical Association of Canada, Short Course 17.Google Scholar
Cabri, L.J., Chryssoulis, S.L., De Villiers, J.P.R., LaFlamme, J.H.G. and Buseck, P.R. (1989) The nature of ‘invisible’ gold in arsenopyrite. The Canadian Mineralogist, 53, 353–362.Google Scholar
Cabri, L.J., Newville, M., Gordon, R.A., Crozier, E.D., Sutton, S.R., McMahon, G. and De-Tong Jiang (2000) Chemical speciation of gold in arsenopyrite. The Canadian Mineralogist, 88, 1265–1281.CrossRefGoogle Scholar
Cathelineau, M., Boiron, M.C., Hollinger, P., Marion, P. and Denis, M. (1989) Gold in arsenopyrites: crystal chemistry, location and state, physical and chemical conditions of depositi on. Economic Geology Monograph, 6, 328–341.Google Scholar
Chryssoulis, S.L., Cabri, L.J. and Salter, R.S. (1987) Direct determination of invisible gold in refractory sulphide ores. Pp. 235–244 in: Proceedings of the International Symposium on Gold Metallurgy–Refractory Gold (Salter, R.S., Wyslouzil, D.M. and McDonald, G.W., editors). Pergamon Press, Toronto, Canada.Google Scholar
Chryssoulis, S.L., Cabri, L.J. and Lennard, W. (1989) Calibration of the ion microprobe for the quantification of precious metals in trace amounts in ore minerals. Economic Geology, 84, 1684–1689.CrossRefGoogle Scholar
Clout, J.M.F., Cleghorn, J.H. and Eaton, P.C. (1990) Geology of the Kalgoorlie goldfield. Pp. 411–431 in: Geology of the Mineral Deposits of Australia and Papua New Guinea (Hughes, F.E., editor). The Australasian Institute of Mining and Metallurgy, Melbourne.Google Scholar
Cook, N.J. and Chryssoulis, S.L. (1990) Concentrations of ‘invisible gold’ in the common sulphides. The Canadian Mineralogist, 28, 1–16.Google Scholar
Dalstra, H.J., Ridley, J.R., Bloem, E.J.R. and Groves, D.I. (1999) Metamorphic evolution of the central Southern Cross Province, Yilgarn Craton, Western Australia. Australian Journal of Earth Sciences, 46, 765–784.CrossRefGoogle Scholar
Fleet, M.E. and Mumin, A.H. (1997) Gold-bearing arsenian pyrite and marcasite and arsenopyrite from Carlin Trend gold deposits and laboratory synthesis. American Mineralogist, 82, 182–193.CrossRefGoogle Scholar
Fleet, M.E., Chryssoulis, S.L., MacLean, P.J., Davidson, R. and Weisener, C.G. (1993) Arsenian pyrite from gold deposits: Au and As distribution investigated by SIMS and EMP, and color staining and surface oxidation by XPS and LIMS. The Canadian Mineralogist, 31, 1–17.Google Scholar
Genkin, A.D., Bortnikov, N.S., Cabri, L.J., Wagner, F.E., Stanley, C.J., Safonov, Y.G., McMahon, G., Friedl, J., Kersin, A.L. and Gamyanin, G.N. (1998) A multidisciplinary study of invisible gold in arsenopyrite from four mesothermal gold deposits in Siberia, Russian Federation. Economic Geology, 93, 463–487.CrossRefGoogle Scholar
Gifford, A.C. (1990) Blue Spec– Golden Spec goldantimony deposits. Pp. 155–158 in: Geology of the Mineral Deposits of Australia and Papua New Guinea (Hughes, F.E., editor). The Australasian Institute of Mining and Metallurgy, Melbourne.Google Scholar
Groves, D.I., Ho, S.E. and Bennett, J.M. (1990 a) Type examples of deposits. Pp. 139–188 in: Gold Deposits of the Archaean Yilgarn Block, Western Australia: Nature, Genesis and Exploration Guides (Ho, S.E., Groves, D.I. and Bennett, J.M., editors). Geology Department (Key Centre) and University Extension, Univers ty of Western Australia, Publication 20.Google Scholar
Groves, D.I., Knox-Robinson, C.M., Ho, S.E. and Rock, N.M.S. (1990 b) An overview of Archaean lode-gold deposits. Pp. 2–18 in: Gold Deposits of the Archaean Yilgarn Block, Western Australia: Nature, Genesis and Exploration Guides (Ho, S.E., Groves, D.I. and Bennett, J.M., editors), Geology Department (Key Centre) and University Extension, University of Western Australia, Publication 20.Google Scholar
Hagemann, S.G. (1990) Wiluna gold deposit. Pp. 156–157 in: Gold Deposits of the Archaean Yilgarn Block, Western Australia: Nature, Genesis and Exploration Guides (Ho, S.E., Groves, D.I. and Bennett, J.M., editors). Geology Department (Key Centre) and University Extension, University of Western Australia, Publication 20.Google Scholar
Hagemann, S.G., Groves, D.I., McNaughton, N.J. and Vearnecombe, J.R. (1991) The geological setting of the Wiluna lode-gold deposits, Western Australia: the highest crustal level endmembers of an Archaean-gold deposit continuum. Pp. 649–656 in: Brazil Gold ‘ 91 (Ladeira, E.A., editor). Balkema, Rotterdam.Google Scholar
Hagemann, S.G., Brown, P.E., Ridley, J., Stern, P. and Fournelle, J. (1998) Ore petrology, chemistry, and timing of electrum in the Archaean hypozonal Transvaal lode gold deposit, Western Australia. Economic Geology, 93, 271–291.CrossRefGoogle Scholar
Hancock, M.C., Robertson, I.G. and Booth, G.W. (1990) Paddington gold deposits. Pp. 395–400 in: Geology of the Mineral Deposits of Australia and Papua New Guinea (Hughes, F.E., editor). The Australasian Institute of Mining and Metallurgy, Melbourne.Google Scholar
Harrison, N., Bailey, A., Shaw, J.D., Petersen, G.N. and Allen, C.A. (1990) Ora Banda gold deposits. Pp. 389–394 in: Geology of the Mineral Deposits of Australia and Papua New Guinea (Hughes, F.E., editor). The Australasian Institute of Mining and Metallurgy, Melbourne.Google Scholar
Hedley, M. and Tabachnick, H. (1968) Chemistry of Cyanidati on. American Cyanamid Company, Mineral Dressing Notes 23.Google Scholar
Hronsky, J.M.A. (1990) Lancefield gold deposit. Pp. 162–165 in: Gold Deposits of the Archaean Yilgarn Block, Western Australia: Nature, Genesis and Exploration Guides (Ho, S.E., Groves, D.I. and Bennett, J.M., editors). Geology Department (Key Centre) and University Extension, University of Western Australia, Publication 20.Google Scholar
Hronsky, J.M.A., Perriam, R.P.A. and Schmulian, M.L. (1990) Lancefield gold deposit, Laverton. Pp. 511–517 in: Geology of the Mineral Deposits of Australia and Papua New Guinea (Hughes, F.E., editor). The Australasian Institute of Mining and Metallurgy, Melbourne.Google Scholar
Johan, Z., Marcoux, E. and Bonnemaison, M. (1989) Gold-bearing arsenopyrite: mechanism of substitution of Au in the crystal structure of FeAsS. Academie des Sciences (Paris), Comptes Rendus, 308, 185–191.(in French).Google Scholar
Kalnejais, J. (1990) Sons of Gwalia gold deposit, Leonora. Pp. 353–355 in: Geology of the Mineral Deposits of Australia and Papua New Guinea (Hughes, F.E., editor). The Australasian Institute of Mining and Metallurgy, Melbourne.Google Scholar
Knight, J.T., Groves, D.I. and Ridley, J.R. (1993) The Coolgarlie Goldfield, Western Australia: districtscale controls on an Archaean gold camp in an amphibolite facies terrane. Mineralium Deposita, 28, 436–456.CrossRefGoogle Scholar
Knight, J.T., Ridley, J.R., Groves, D.I. and McCall, C. (1996) Syn-peak metamorphic gold mineralization in the amphibolite-facies, gabbro hosted Three Mile Hill deposit, Coolgardie Goldfield, Western Australia: a high-temperature analogue of mesothermal gabbro-hosted gold deposits. Transactions of the Institution of Mining and Metallurgy (Section B: Applied earth science), 105, B175–B199.Google Scholar
Kretschmar, U. and Scott, S.D. (1976) Phase relations involving arsenopyrite in the system Fe-As-S and their application. The Canadian Mineralogist, 14, 364–386.Google Scholar
Kyin, A. (1995) A mineralogical investigation of arsenical gold ore deposits from the Archaean of Western Australia. MSc Thesis, Curtin University of Technology, 229 pp.Google Scholar
Lapointe, B. and Chown, E.H. (1993) Gold-bearing ironformation in a granulite terrane of the Canadian Shield: a possible deep-level expression of an Archaean gold-mineralizing system. Mineralium Deposita, 28, 191–197.CrossRefGoogle Scholar
Larocque, A.C.L., Hodgson, C.J., Cabri, L.J. and Jackman, J.A. (1995) Ion-microprobe analysis of pyrite, chalcopyrite and pyrrhotite from the Mobrun VMS deposit in northwestern Quebec: evidence for remobilization of gold. The Canadian Mineralogist, 33, 373–388.Google Scholar
McGoldrick, P. (1990) Wiluna gold deposits. Pp. 309–312 in: Geology of the Mineral Deposits of Australia and Papua New Guinea (Hughes, F.E., editor). The Australasian Institute of Mining and Metallurgy, Melbourne.Google Scholar
McPheat, I.W., Gooden, J.E.A. and Townend, R. (1969) Submicroscop ic gold in a pyrite concentrate. Proceedings of the Australasian Institute of Mining and Metallurgy, 231, 19–25.Google Scholar
Mikucki, E.J. and Groves, D.I. (1990) Gold transport and depositional models Pp. 278–284 in: Gold Deposits of the Archaean Yilgarn Block, Western Australia: Nature, Genesis and Exploration Guides (Ho, S.E., Groves, D.I. and Bennett, J.M., editors). Geology Department (Key Centre) and University Extension, University of Western Australia, Publication 20.Google Scholar
Mumin, A.H., Fleet, M.E. and Chryssoulis, S.L. (1994) Gold mineralization in As-rich mesothermal gold ores of the Bogosu-Prestea mining district of the Ashanti Gold Belt, Ghana: remobilization of ‘invisible’ gold. Mineralium Deposita, 29, 445–460.CrossRefGoogle Scholar
Myers, J.S. (1997) Tectonic evolution of the Yilgarn Craton. Pp. 7–10 in: Kalgoorlie ‘97: An International Conference on Crustal Evolution, Metallogeny and Exploration of the Yilgarn Craton–an Update (Cassidy, K.F., Whitaker, A.J. and Liu, S.F., compilers). Australian Geological Survey Organization, Record 1997/41.Google Scholar
Neumayr, P., Cabri, L.J., Groves, D.I., Mikucki, E.J. and Jackman, J.A. (1993) The mineralogical distribution of gold and relative timing of gold mineralization in two Archaean settings of high metamorphic grade in Australia. The Canadian Mineralogist, 31, 711–725.Google Scholar
Norris, N.D. (1990) New Celebration gold deposits. Pp. 449–454 in: Geology of the Mineral Deposits of Australia and Papua New Guinea (Hughes, F.E., editor). The Australasian Institute of Mining and Metallurgy, Melbourne.Google Scholar
Oberthür, T., Weiser, T., Amanor, J.A. and Chryssoulis, S.L. (1997) Mineralogical siting and distribution of gold in quartz veins and sulfide ores of the Ashanti mine and other deposits in the Ashanti belt of Ghana: genetic implications. Mineralium Deposita, 32, 2–15.CrossRefGoogle Scholar
Perring, C.S., Barley, M.E., Groves, D.I., McNaughton, N.J. and Ridley, J.R. (1990) Fluid and metal sources. Pp. 285–291 in: Gold Deposits of the Archaean Yilgarn Block, Western Australia: Nature, Genesis and Exploration Guides (S.E., Ho, D.I., Groves and J.M., Bennett, editors), Geology Department (Key Centre) and University Extension, University of Western Australia, Publication 20.Google Scholar
Rolley, P.J. and Baxter, J.L. (1990) Marvel Loch gold deposit. Pp. 297–300 in: Geology of the Mineral Deposits of Australia and Papua New Guinea (Hughes, F.E., editor). The Australasian Institute of Mining and Metallurgy, Melbourne.Google Scholar
Sharp, Z.D., Essene, E.J. and Kelly, W.C. (1985) A reexamination of the arsenopyrite geothermometer: pressure considerations and applications to natural assemblages. The Canadian Mineralogist, 23, 517–534.Google Scholar
Simon, G., Kesler, S.E. and Chryssoulis, S.L. (1999 a) Geochemistry and textures of gold-bearing arsenian pyrite, Twin Creeks, Nevada: implications for deposition of gold in Carlin-type deposits. Economic Geology, 94, 405–422.CrossRefGoogle Scholar
Simon, G., Huang, H., Penner-Hahn, J.E., Kesler, S.E. and Kao, L.-S. (1999 b) Oxidation state of gold and arsenic in gold-bearing arsenian pyrite. American Mineralogist, 84, 1071–1079.CrossRefGoogle Scholar
Skwarnecki, M.S. (1990) Sons of Gwalia gold deposit. Pp. 149–151 in: Gold Deposits of the Archaean Yilgarn Block, Western Australia: Nature, Genesis and Exploration Guides (Ho, S.E., Groves, D.I. and Bennett, J.M., editors). Geology Department (Key Centre) and University Extension, University of Western Australia, Publication 20.Google Scholar
Swager, N. (1990) Bayleys gold deposit, Coolgardie. Pp. 455–457 in: Geology of the Mineral Deposits of Australia and Papua New Guinea (Hughes, F.E., editor). The Australasian Institute of Mining and Metallurgy, Melbourne.Google Scholar
Tarnocai, C.A., Hattori, K. and Cabri, L.J. (1997) ‘Invisible’ gold in sulphides from the Campbell mine, Red Lake greenstone belt, Ontario: evidence for mineralization during the peak of metamorphism. The Canadian Mineralogist, 35, 805–815.Google Scholar
Thorman, C.H., DeWitt, E., Maron, M.A.C. and Ladiera, E.A. (2001) Major Brazilian gold deposit s. Mineralium Deposita, 36, 218–227.CrossRefGoogle Scholar
Tomkins, A.G. and Mavrogene s, J.A. (2001) Redistribution of gold within arsenopyrite and loellingite during pro-and retrograde metamorphism: application to timing of mineralization. Economic Geology, 96, 525–534.CrossRefGoogle Scholar
Vaughan, J.P. (1991) Mineralogical factors in the processing of Archaean sulphide gold ores. Pp. 61–67 in: Proceedings of the Fifth AusIMM Extractive Metal lurgy Conference. The Australasian Institute of Mining and Metallurgy, Melbourne.Google Scholar
Vaughan, J.P. and Corrans, I.J. (1992) Mineralogy and processing characteristics of arsenical gold ores– phase 2. Minerals and Energy Research Institute of Western Australia, Report 87, 217 pp.Google Scholar
Vaughan, J.P., Bacigalupo-Rose, S. and Dunne, R. (1989) Mineralogy and processing characteristics of arsenical gold ores. Minerals and Energy Research Institute of Western Australia, Report 51, 85 pp.Google Scholar
Vaughan, J.P., Hopf, S., Stokes, P. and Roberts, F.I. (1997) Process mineralogy of Kalgoorlie goldtelluride ores. Pp. 182–186 in: Proceedings of the 5th International Congress on Applied Mineralogy in the Minerals Industry Niedbalska, A., Szymański, A. and Wiewióra, A., editors). SUBDAN-DRUK, Warsaw.Google Scholar
Wagen, J.H.F. and Wiegard, J. (1986) The Sheba gold mine, Barberton Greenstone Belt. Pp. 155–161 in: Mineral Deposits of Southern Africa, Vol I. (Anhaeusser, C.R. and Maske, S., editors). Geological Society of South Africa, Johannesburg.Google Scholar