Process development for elemental recovery from PGM tailings by thermochemical treatment: Preliminary major element extraction studies using ammonium sulphate as extracting agent.

摘要: Mine tailings can represent untapped secondary resources of non-ferrous, ferrous, precious, rare and trace metals. Continuous research is conducted to identify opportunities for the utilisation these materials. This preliminary study investigated possibility extracting major elements from South African associated with mining Platinum Group Metals (PGM) at Two Rivers mine operations. These PGM typically contain four (11% Al2O3; 12% MgO; 22% Fe2O3; 34% Cr2O3), lesser amounts SiO2 (18%) CaO (2%). Extraction was achieved via thermochemical treatment followed by aqueous dissolution, as an alternative conventional hydrometallurgical processes. The step used ammonium sulphate, a widely available, low-cost, recyclable chemical agent. Quantification efficiency process required development optimisation dissolution technique. Dissolution in water promoted formation iron precipitates, which could be prevented leaching thermochemically-treated 0.6M HNO3 solution. best extraction efficiencies were aluminium (ca. 60%) calcium 80%). 35% 32% silicon also extracted, alongside chromium (27%) magnesium (25%). Thermochemical using sulphate may therefore promising technology valuable tailings, subsequently converted value-added products. However, it not element-selective, found compete reagent form water-soluble sulphate–metal species. Further this integrated process, aims achieving full potential currently underway.