1. Case studies

With the exception of a few details, all the cases considered below concern the process comprising smelting for matte, conversion of the latter into white matte, hydrometallurgical etching of the latter with sulfuric acid and under oxygen pressure to recover electrolytic copper, nickel by crystallization of the sulfate or by solvent, cobalt by solvent and a residue of precious metals that can be processed by the methods described at the end of this section. . This method has been adopted by virtually all PGM primary metallurgists, with adaptations to suit each particular case. After Inco replaced the conventional selective precipitation process for separating PGMs with the solvent extraction process at Acton (UK) in 1971, the latter was further developed at Matthey Rustenburg and Lonrho Refineries, supplemented by extraction with conventional resins or silica gels with...