Description
⌕ Enlarge Image
Platinum is a lustrous, grey white, transition metal in its natural solid state. It is resistant to corrosion and has strong catalytic properties. Platinum has an atomic weight of 195.084, a melting point of 3214.9 °F, and a boiling point of 6917 °F. Some common uses of platinum include: as a catalyst component in catalytic converters and fuel cells, in the form of electrodes for electrolytic reactions, as a component in precious jewelry, as a catalyst in glow plugs, and as a component for certain types of photography.
Isolation
Platinum does occur in its free state in nature, but it is very rare. Isolation processes can be used to isolate platinum from such minerals as iridium and platiniridium.
⌕ Enlarge Image
As a rare and precious metal, platinum is only extracted and isolated on a commercial basis; small scale laboratory isolation of platinum is too expensive and energetically inefficient. The isolation process of platinum begins with treating the ore it occurs in with a mixture of hydrochloric acid and nitric acid. This results in a solution which contains any gold and palladium complexes in the mineral, in addition to a hydrogen platinum chorine compound. Iron chloride is added to the solution to precipitate out any gold; impure platinum is removed by treating the solution with ammonium chloride in the form of a precipitate. The impure precipitate compound containing platinum is then burned resulting in a platinum sponge which contains impurities. Further platinum isolation is carried out by treating the sponge with a mixture of hydrochloric acid and nitric acid; sodium bromated removes additional impurities, and the resulting product is treated with ammonium hydroxide and then burned which yields pure platinum metal isolation.