Most of the PGM deposits currently in production are associated with ultrabasic dunitic and gabbroic rocks, containing copper, nickel and iron sulfides. The proportion of PGMs in these deposits is variable, and generally requires adaptation of industrial processes for their recovery. However, the classic industrial route is to treat mixed copper-nickel-platinum sulfide concentrates with smelting/conversion operations, followed by hydrometallurgical operations to recover the base metals (Cu, Ni). The latter concentrate the platinoids in the leaching residues. From these residues, the PGMs are extracted and then separated by hydrometallurgical routes combining various techniques (dissolution, selective precipitation, distillation, solvent extraction, resins, etc.).
The wide variety of uses for PGMs makes them difficult to recycle. Waste products are often too complex to make recycling economical.
Environmental protection depends on the type of industry (mining, metallurgy, chemical). Some products present fire and explosion risks. Toxicity is expressed above all in the form of superficial allergies, and in the ingestion of soluble salts.
Note :
A first article
by the same authors presents platinum ores, their deposits, and extraction and separation processes.