How Is Platinum Mined In South Africa
On the African continent, mining for platinum or platinum group metals (PGM) is common, and South Africa is home to more than 80% of the world’s deposits.
South Africa appears to be the obvious place for investors to begin their exploration of the PGM market in Africa. With more than 80 PGM mining projects, it possesses the majority of the continent’s platinum mining projects, which are held by just 11 platinum mining corporations.
Where does South Africa’s platinum come from?
South Africa contributes around 80% of the world’s platinum, while its palladium production accounts for nearly 40% of global gross production. The Bushveld Igneous Complex in South Africa, which dates back 2 billion years, is where PGM is concentrated, particularly in complexes in the Limpopo and North.
Steps In The Platinum Mining Process: West Provinces
Smelting
Smelting is used to remove the sulphide minerals linked to the noble metals from the gangue (oxide and silicate) minerals. The sulphide minerals create a matte that is further processed, and the gangue is thrown away as slag. Two liquid phases emerge when the concentrate melts: a lighter, silicate- and iron-rich slag with a relative density of around 2.7 to 3.3, and a denser, nickel- and copper-sulphide- and other base- and precious-metal-rich molten matte with a relative density of roughly 4.8 to 5.3. The rate at which molten matte prills coalesce with other prills to increase in size, then separate from the slag under the force of gravity, depends on the viscosity.
Converting
In order to oxidize much of the iron and sulphur during the conversion process, air is blasted into the molten matte over the course of a few hours (primarily of FeS). The converters currently in use are of the Peirce-Smith type; they have a horizontal cylindrical shape and a top opening for charging and discharging. Tuyeres for blowing are arranged in horizontal rows along the lower back of the vessel, and pouring is accomplished using a tilting mechanism. In order to create an iron silicate slag with a composition similar to fayalite (2FeO.SiO2) and some dissolved magnetite, silica sand is added to the converter. This fluxes the iron oxide that is created when iron is oxidized.A portion of the sulfur departs the system as sulphur dioxide in the gas phase (SO2). The oxidation reaction is sufficiently exothermic to keep the converter’s temperature at or near 1250 oC. If the converter gets too hot, cool feed or reversion materials (spillages, etc.) are added to it to lower the temperature. The matte is only poured out once it has reached the desired iron content. The converter slag is periodically skimmed off. The choice of the ensuing refining process determines how much iron and sulfur must be removed during conversion. The converter matte is either cast into refractory-lined pits or molds made of cast iron, then crushed there, or it can be granulated by being poured into a stream of water moving extremely quickly.
Off-gas management
It is still standard procedure to discharge furnace exhaust gases to the atmosphere through a high stack after they have passed through an electrostatic precipitator. Sulphuric acid can be made from the SO2 in gas, but this is difficult due to the low concentration and inconsistent production from the furnaces and converters.
Refining
The base-metal refinery typically mills the converter matte before treating it, and then uses sulphuric acid leaching to recover the copper and nickel. The high-grade PGM concentrate that is delivered to the precious metals refinery for the final separation of the pure precious metals is typically made up at most plants by the leach residue.
Where does the platinum in South Africa originate from?
Around 80% of the world’s platinum supply come from South Africa, while roughly 40% of the world’s total palladium production comes from this country. PGM is concentrated in the 2 billion-year-old Bushveld Igneous Complex of South Africa, particularly in complexes located in the provinces of Limpopo and North West.
In South Africa, how many platinum mines are there?
28 PGM mines that are active. 31 ongoing initiatives. South Africa is home to 28 mining firms that produce platinum.
How deep is a mine for platinum?
Five decline shafts—1 shaft, 2 shaft, 4 shaft, 5 shaft, and 6 shaft—provide access to the mine. Shafts 4 and 5 are used for mining operations at 450 meters below the surface.
