METHOD OF RECOVERING PRECIOUS METALS FROM INTERMEDIATE PRODUCTS Russian patent published in 1998 - IPC

FIELD: pyrometallurgy and precious metal recovery. SUBSTANCE: intermediate products are submitted to oxidative firing to produce cinder, which is melted in presence of massicot and carbonaceous reducing agent to collect precious metals in lead, cinder being preliminarily mixed with alkali and/or alkali-earth metal halides, massicot, and carbonaceous reducing agent. Melting is effected at temperature higher than melting temperature of halide, after which mixture is aged at this temperature for further 0.5 h to concentrate lead collecting precious metals in its bottom phase. The latter is separated from oxides dissolved in alkali and/or alkali-earth metal halide melt. EFFECT: simplified process, reduced power consumption, and increased precious metal recovery. 2 cl