METHOD OF EXTRACTING PLATINUM FROM AN INDUSTRIAL SALT OF AMMONIUM HEXACHLOROPLATINATE Russian patent published in 2020 - IPC C22B11/00 C22B3/44 

FIELD: metallurgy.

SUBSTANCE: invention relates to hydrometallurgy of platinum metals. Extraction of platinum from industrial salt of ammonium hexachloroplatinate involves preparation of water pulp of ammonium hexachloroplatinate and its treatment with carbon monoxide with CO under intense stirring, atmospheric pressure and temperature of 60 °C until complete dissolution of the salt. Sediment of platinum and palladium is separated, followed by treatment of solution H₂PtCl₄ chlorine and separating precipitate of pure ammonium hexachloroplatinate salt with subsequent calcination causing palladium reduction and platinum deposition in amount of 5–10 %. Pulp of industrial salt of ammonium hexachloroplatinate is repeatedly prepared, into which a filtrate is added, which is a solution of H₂PtCl₄ obtained at the previous step, in an amount required to obtain ratio Pt (II) : Pt (IV) in mixed pulp is equal to 2 %. Mixed pulp is re-treated with carbon monoxide CO, repeating all operations of the previous stage. Pure salt of ammonium hexachloroplatinate is precipitated, and the precipitate is filtered and washed on filter with 10 % aqueous solution of ammonium chloride. After drying and calcination, a plastic platinum sponge is obtained.

EFFECT: invention improves the quality of the obtained product in the form of a plastic platinum sponge both in content of impurities and plasticity.

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