Abstract
The Molai sulphide deposit situated in S.E.Peloponnese, Greece, was located after a systematic exploration programme which commenced in 1980. Geostatistical evaluation of the drilling campaign results indicated mineable ore reserves of 2.3 × 106 tons with an average estimated content of Zn: 9,0%, Pb: 1,8% and Ag: 50 g/t.
The geological and mineralogical features led to the conclusion that the Molai ore body belongs to the stratiform, syngenetic, volcanogenic massive sulphide deposits. Detailed mineralogical analysis of drill core and representative bulk ore samples indicated sphalerite as the main Zn bearing mineral, while smithsonite and monheimite were also observed. Galena and small quantities of anglesite and cerrusite were recorded as the Pb-bearing minerals. Silver is encountered in the tetrahedrite-tennantite mineral group mainly associated with sphalerite and in the Ag-Sb bearing minerals diaphorite, pyrargirite and stephanite observed as inclusions within galena.
The fine dissemination and association of base metal sulphides, combined with the presence of oxidised zinc and lead minerals adversely affect the beneficiation of the Molai sulphide deposit. The liberation size varies from 26µm for sphalerite to 12µm for galena and 2µm for anglesite. Prolonged grinding and high reagent consumption is required to improve zinc recoveries. Metal losses in slimes, early zinc activation in the galena circuit and silver distribution between the lead and zinc concentrate are recorded, as major problems encountered in the differential flotation of the Molai sulphide ore.
In this article mineralogical analysis data are employed to corroborate the prevailing theories on the Molai ore body genesis and formation as well as to assist in developing an economic beneficiation process for the treatment of this complex, finely disseminated sulphide mineralisation.
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References
IGME: “Concise report on the Prefeasibility Study of the Molai massive sulphide deposit in Laconia”. Institute of Geological and Mineralogical Exploration, Athens, 1985.
METBA: “Optimisation of the exploitation of thin vein polymetallic sulphide deposits through mathematical modelling and rock mechanics, an application to the Molai mine” CEC contract No. MA1M-0025-C(TT) 2nd Progress Report, Athens, December 1989.
METBA: “Molai Base metal massive sulphides” CEC Project GRE 02/09/002, 2nd Progress Report, Athens, April 1990.
IGME, BRGM, ITMI: “A process design study for a finely disseminated partially oxidized complex sulphide ore from the Molai area Southern Greece” CEC Contract No. MA1M-0025-C(TT). 2nd Progress Report, Athens, May 1989.
IGME, BRGM, IMM: “A process design study for a finely disseminated partially oxidized complex sulphide ore from the Molai area Southern Greece” CEC Contract No. MA1M-0025-C(TT). 3rd Progress Report, Athens, November 1989.
Angelopoulos C. and Constantinides, D.C.: “The Molai Zn-Pb-Ag deposit, Lakonia, S.E.Peloponnese”, Bull Geol.Soc. Athens, Greece, Vol.XX/2, 1988, p.305–320.
Christakos, G.: “A computer program for the analysis and estimation of spatial functions”, Intern. Report, Civil Eng.Dpt, MIT< Boston, Mass. 1980.
Angelopoulos, C. & Constantides, D.C: “The Molai zinc-silver-lead deposit, Lakonia/Greece”, Intern. South Eur. Symp. on Expl. Geoch., Field trips guide book, Athens 1986, pp.61–67.
Amov, G.B: “Evolution of uranogenic and thorogenic lead. A dynamic model of continuous isotopie evolution”. Earth and Planet Sci. Letters 65, Elsevier, Amsterdam, 1983, pp 61–74.
Brauer, R.: “Das Praneugen im Raum Molai Talanta/S.D.-Lakonien (Peloponnes, Griechenland)” Inang.- Dissert. zur Erlangung des Doctorgrades. Frankurt am, 1982.
Ohmoto, H and Skinner, J.P.: “The Kuroko and Related Volcanogenic Massive Sulphide deposits”. Econ. Geol. Monogr. 5, 1983.
Norrgran, D.A. and Armstrong, R.O.: “Developing a selective flotation concentration technique for polymetallic ores” in Complex Sulphides, eds. A.D. Zunkel, R.S. Boorman, A.E. Morris, R.J. Wesely, TMS, 1985, pp. 37–54.
Finkelstein, N.P. Allison, S.A.: “The Chemistry of Activation, Deactivation and Depression in the Flotation of Zinc Sulphide. A review”. In Flotation, ed. M.G. Furestenau, Vol. 1, New York, 1976, pp. 414–457.
Ingerttila, K. Kaukkanen J., Hintikka, V.: “On Mineralogy and Flotation test of Molai ore”, Technical Research Center of Finland, 1986.
Grossou-Valta, M. et al.: “Discussion on the possible treatment of Molai mixed sulphide ore after experimental investigation of typical samples”. Metallurgical Research Reports No.37, Institute of Geology and Mineral Exploration, Athens, 1984.
Bulatovic, S.M., Wyslouzil, D.M.: “Selection of reagent scheme to treat massive sulphide ores” in Complex Sulphides ed. D. Zunkel, R.S. Boorman, A.E. Morries, R.J. Wesely, TMS. 1985, pp. 101–137.
Cases, J.M.: “Finely disseminated complex sulphide ores” in Complex Sulphide Ores, ed. M.J. Jones, IMM Conference Proceedings 1980, pp 234–247.
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Grossou-Valta, M., Adam, K., Constantinides, D.C., Prevosteau, J.M., Dimou, E. (1990). Mineralogy of and potential beneficiation process for the Molai complex sulphide orebody, Greece. In: Gray, P.M.J., Bowyer, G.J., Castle, J.F., Vaughan, D.J., Warner, N.A. (eds) Sulphide deposits—their origin and processing. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-0809-3_8
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DOI: https://doi.org/10.1007/978-94-009-0809-3_8
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