Platinum

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Platinum is the second most common of the platinum group metals (PGM) after palladium. Thanks to it's chemical resistance, even at high temperatures, it has found a wide variety of technological uses, for example as catalysts, in lab ware, as anodes or on turbine blades. It is a silverish-white ductile metal with a melting point of 1768.3 °C (3214.9 °F). The name platinum comes from the Spanish "platina", meaning "little silver".

Contents

Refining

(Short description of refining platinum)

Ref : Use potassium chloride instead of ammonium chloride

Ref : Kadriver refines black PGM powders

Testing

Testing of platinum is made by ICP-MS difference and in accordance to an ISO/ASTM standard.

Ref : Posting by Lou

Safety

Platinum in it self is very inert and can be used for the casing of implanted devices as pace makers. In it's solution form as tetravalent platinum it can give rise to platinum allergy.

Ref : GRF : Safety thread, post about platinum salts.

Dissolving platinum

Platinum is quite resistant to most acids. It can easily withstand all acids by them self, but just as gold it can be dissolved in aqua regia or by hydrochloric acid combined with chlorine.

Platinum dissolved in aqua regia.

Pt + 4HNO3 + 6HCl -> H2PtCl6 + 4 NO2 + 4H2O

Platinum dissolved in hydrochloric acid and chlorine.

Pt + 2Cl2 + 2HCl -> H2PtCl6

In both cases the end product is hexachloroplatinic acid.

Platinum has one interesting quirk, when it is alloyed with silver it can actually be dissolved in nitric acid only. This fact can be used to remove platinum from gold alloys by inquarting. The platinum follows the silver as a nitrate salt into solution, leaving a gold sponge that is easy to refine with aqua regia or to melt down directly.

Videos

References

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