Precious Metals
The Impala Platinum concentrator and smelter was originally built to treat ores from the Merensky Reef but was later used to treat ores from the UG2 Reef. For several years both ore types were treated in the same mill and float circuit to produce Ni, Cu, Co, PGM concentrates but now the plant feed is almost entirely UG2. The concentrate is dewatered before being treated further in 6 in line AC smelting furnaces and PierceSmith converts.
Milling Section of Impala Concentrator in Rustenburg
Impala's UG2 Plant
The UG2 Reef is a chrome reef and very different from the more silicate based Merensky Reef. As such the optimum processing parameters for the UG2 were different to those for the soon to be depleted Merensky ore. A new process for treating the chrome reefs was developed at the Gencor Process Research Laboratories which became known as the MF2 process.
The adjacent photo is of the trains one to three bacterial leach reactors at the Sansu Biox plant with Ashanti Goldfields in Obuasi, Ghana. Each train is designed to treat 11 tph of refractory gold concentrate ahead of the CIL circuit. This plant has now been extended to four trains and is still in operation. It is the largest Biox plant in the world.
Top and bottom views of 2x banks of Ion Exchange column at the Petropavlovsk gold operation in Eastern Russia
Gold nuggets panned from a Californian mine
Silver vat leaching in Mexico using ammonium thiosulphate as the leachant
