Review of Recovery of Platinum Group Metals from Copper Leach Residues and Other Resources

Extraction of Platinum Group Metals

“…In South Africa, the PGM ore is mined in the western and eastern limb of the Bushveld Igneous Complex [8]. Within the Bushveld Igneous Complex, the Merensky reef, the Platreef and Upper Group 2 (UG2) reef are exploited for platinum production [1,4,9]. Merensky and Platreef have similar chemical and mineral composition [6,10].…”

“…Typical process route for treating PGM ore with the approximate PGM grade in each process is shown in Figure 1 [1,7,9].…”

“…The PGM ore is initially treated in primary and secondary crushers after which it is sent to rod and ball milling circuits. The milled PGM ore is treated using gravity separators and flotation cells; xanthate and dithiophosphate collectors are typical reagents used for flotation at a pH of 7.5-9 [1]. A sulphide-rich PGM concentrate is produced in the flotation cells [6].…”

“…The slag phase of the converter contains significant amounts of entrained PGM and is recycled to the smelting furnace to recover the entrained PGM. The converter matte is cooled, milled and treated in base metals refinery (BMR) [1,9].…”

“…Platinum group metals (PGMs) are a group of six elements, namely iridium (Ir), osmium (Os), platinum (Pt), palladium (Pd), rhodium (Rh) and ruthenium (Ru) [1,2]. PGMs together with gold and silver are classified as noble or precious metals because of their high corrosion and oxidation resistance [1][2][3]. The world's reserves of platinum group metals/elements are estimated at 100 million kilogrammes, of which over 80% is contained in South Africa's Bushveld Igneous Complex [4].…”