Gold–sulphide deposits of the Russian Arctic zone: Mineralogical features and prospects of ore benefication

Abstract

In this study, the forms of silver occurrence and behaviour during extraction from primary gold–sulphide deposits in the carboniferous strata of the Arctic zone of Russia are analysed. Detailed mineralogical and technological studies reveal that the silver is concentrated in tetrahedrites, whereas deposits of this geological–industrial type are usually characterised by other silver-bearing minerals. The silver content in the tetrahedrite varies from 12 to 22 wt.%; silver is also found as an isomorphic impurity in native gold and as a solid solution in sulphide minerals. Moreover, the possibility of implementing a combined gravity–flotation scheme with ore production is discussed. The final concentrates from this process are shown to be suitable for subsequent autoclave oxidation and cyanidation of refractory gold-bearing ores. The aim of the new reagent addition is to enhance the comprehensive usage of ores.