METHOD OF GOLD RECOVERY FROM MINERAL RAW MATERIALS Russian patent published in 1998 - IPC

FIELD: processing of ore, heavy concentrates and wastes of mining processes. SUBSTANCE: method includes grinding of initial raw materials, adding of collector (grainy lead or grainy lead alloy with silver, or galenite) and alkali sodium or alkali potassium, or mixture of alkali sodium with alkali potassium. The mixture is melted in furnace, melt is kept in heated state depending on its temperature; the lower temperature, the longer is holding. Then melt is leached with water, liquid part is withdrawn, and lead bullion is separated; by cupellation melting of the latter gold is recovered. Remaining slag is treated with solution of hydrochloric acid. Practically all barren rock is removed by leaching. EFFECT: higher recovery of gold in bound or concealed state.