Process for recovering platinum group metals from ores also containing nickel, copper and iron

Abstract From the Canadian patent

Abstract of the Disclosure, A process is described for the separation of platinum group metals (PGM) from ores also containing iron nickel and copper as sulfides. The minerals in the ore are first concentrated by flotation and the ore concentrate is melted in an electric furnace to form a matte containing at least 95% of the precious metals. The matte is granulated while molten to granules of a mean size not greater than about 210 micrometers (µm) and then pressure leached with sulfuric acid and oxygen to separate the nickel iron and, copper as their respective sulfates while recovering the, PGM as a residue. Concentration of the leach residue by roasting and subsequent acid leaching yields …