Platinum Production
Platinum Production
Placer mining platinum, platinum scraps or concentrates are dissolved in aqua regia. The excess HNO3 is removed by adding ethanol and sugar syrup, which also reduces iridium and palladium until Ir3+ and Pd2+. On the next step after (NH4)2PtCl6 is precipitated by NH4Cl, the sediment is dried and baked at temperature gradually increased until the contaminated platinum sponge appears at 800-1000°C. Pure platinum is obtained dissolving the sponge in aqua regia, reprecipitation and baking. Platinum sponge is remelted, and platinum black is obtained after salts reduction. Phosphate or cis-diaminonitrite electrolytes are used in platinum coating.