CURRENT STATUS OF DETERMINATION OF MINERALOGICAL BALANCES FOR PLATINUM-GROUP ELEMENT-BEARING ORES

Acquiring a thorough mineralogical understanding of ores that contain platinum-group elements (PGE) presents a major challenge to applied mi neralogists in spite of the considerable advances that have been made over the past decade. The PGE may occur as discrete platinum-group min erals, as dilute solid solutions in major sulphide minerals and in les s abundant telluride, arsenide and sulpharsenide minerals. It has also been postulated that very dilute solid solutions of PGE occur in oxid e and silicate minerals in some deposits. The mineralogy and distribut ion of the PGE are variable, both within a single ore deposit and betw een different ore types. However, it should now be possible to determi ne complete PGE mineralogical balances by the judicious use of various techniques, including reliable bulk assays, ore microscopy, image ana lysis and electron, proton and ion microprobes.