Iridium Production
Iridium Production
Anode slime of copper-nickel metallurgy is the main source of Iridium production. Initially gold, paladium and platinum are isolated from the platinum group metals concentrates. The Ruthenium, Osmium and Iridium residue is fused with KNO3 and KOH (the mentioned potash). The melt is leached by water, after which the solution is oxidized by chlorine and the OsO4 and RuO4 are sublimated. Meanwhile the iridium containing residue is melted with Na2O2 and NaOH, the fusion treated by aqua regia and, after that, by NH4Cl solution. (NH4)2[IrCl6] settled out after this treatment is then baked with metal iridium output.
Another method of iridium isolation from solutions includes extraction of hexachloroiridates by higher aliphatic amines. Iridium may be separated from basic metal by ion exchange methods. Iridium is obtained from minerals of osmiridium group by melting with BaO2 through hydrochloric acid and aqua regia treatment, OsO4 sublimation and, finally, (NH4)2[IrCl6].