The leaching of base metals from the calcines produced by the roasting of pyrite concentrates

Nicol, M.J.ORCID: 0000-0002-8757-161X (1984) The leaching of base metals from the calcines produced by the roasting of pyrite concentrates. In: MINTEK 50, 26-30 Mar 1984, Sandton, South Africa

Abstract

A number of gold and uranium plants in South Africa concentrate the pyrite in the ore residue by flotation and roast the concentrate for the production of sulphuric acid. The calcine produced, which is predominantly hematite, is generally subjected to cyanidation for the recovery of gold and silver. The calcines often contain economically significant quantities of copper, nickel , cobalt and uranium. Prior treatment of the calcine for the recovery of these metals would be desirable in terms of the value of the products. Several processes for the leaching of the base metals from plant calcines have been investigated, and an important general conclusion is that an adequate recovery of the base metals requires that a large proportion of the iron should also be extracted. This observation led to a more extensive investigation of the kinetics of leaching of various iron oxides. The application of electrochemical theory and techniques resulted in a fuller understanding of the various factors that govern the rate of leaching of iron oxides. As a result of this fundamental work, alternative treatment schemes that should yield more efficient extraction from calcines were suggested. Several of these possibilities were investigated, and the most promising were found to require reducing conditions during the leach, or prior partial reduction of the calcine to magnetite or wustite

Item Type:	Conference Paper
URI:	http://researchrepository.murdoch.edu.au/id/eprint/30107

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