The platinum-group metals, ie, platinum, palladium, rhodium, ruthenium, osmium, and iridium, all have high melting points and exceptional corrosion resistance. Platinum, rhodium, and iridium are particularly stable to oxidation at high temperatures. These metals, especially platinum and palladium, show exceptional catalytic properties.
In nature, platinum-group metals frequently occur in conjunction with nickel, copper, and iron sulfides. The principal producing region is South Africa, but other commercially important deposits exist in Canada and CIS. In the refining of these metals, solvent extraction technology is increasingly replacing conventional hydrometallurgical processes. Benefits include increased recovery, improved efficiency, and significantly shortened process time. Resources and recovery processes are discussed.
The platinum-group metals are extensively used as catalysts. Applications include pollution control catalysts for gasoline and diesel vehicles, control of emissions of organics and nitrous oxides from industrial installations, fuel cells and process catalysts in the chemical industry, including nitric acid and chlorine production, and petroleum organic synthesis refining. Platinum-group metals are also used as jewelry, in the glass industry, in electronic components, in spark plugs, on turbine blades, and in medical devices. Modern cardiovascular surgery and anticancer chemotherapy both employ these metals.