Discuss the extraction of platinum and name its important ores.

Begin by identifying the major sources of platinum. Platinum is commonly obtained from ores such as sperrylite (PtAs2), cooperite (PtS), and platiniridium (an alloy of platinum and iridium). Another significant source of platinum is as a byproduct in nickel-copper ores.

Platinum extraction is a multi-step process: 1. The ore is crushed and milled to reduce the size of the rock particles and to expose the minerals which contain the pgm. The particles are mixed with water and special reagents and air is blown through the mixture. The minerals attach themselves to the air bubbles and are carried to the surface where a ‘froth’ is formed, which is then skimmed off and the pgm content is increased. 2. The product of this process, known as ‘flotation concentrate’, is then dried and smelted in an electric furnace at temperatures of up to 1,500 degrees Celsius. Because of the affinity of nickel and copper for sulfur, the metals are converted to sulfides which separate into a different layer. The residue, which is rich in palladium, platinum and rhodium, forms a separate layer. Any residual gangue phases (i.e. minerals other than pgm) and excess reagents are disposed of.3. The pgm-containing particles are converted to a form suitable for final purification by a chemical process known as ‘aqua regia’. The final stage is the production of pure metal for use in a wide range of products and applications.