Leaching/flotation processing of complex sulphide ores

CIM Bulletin, Vol. 80, No. 907, 1987

FRANCISZEK LETOWSKI, Mineral Industry Research Laboratory, University of Alaska-Fairbanks, Fairbanks, Alaska

Recovery of precious metals associated with a sulphidic matrix has an important economic effect on complex sulphide ore treatment. Because a significant portion of the silver and gold associated with pyrite are rejected to tailings during the selective flotation of pyritic Zn-Pb-Cu ore, other ore processing routes have been investigated. Direct leaching of the ore with ferric sulphate solution followed by separation of different components of the solid suspension by flotation was applied. Such a process allows for: production of zinc sulphate solution; transformation of galena PbS to insoluble lead sulphate PbSO4 and its accumulation in a non-floatable fraction together with precipitated geothite FeOOH and other insoluble gangue minerals; separation of sulphur and non-decomposed sulphides in the floatable fraction.

Keywords: Hydrometallurgy, Leaching-flotation process, Flotation, Recovery processes, Ore processing, Delta region, Extraction metallurgy.