METHOD OF INTEGRATED EXTRACTING PRECIOUS METALS FROM TAILS Russian patent published in 2017 - IPC C22B11/06 C22B7/04 

FIELD: chemistry.

SUBSTANCE: raw material is dried to a moisture content of 6 wt %, mixed with a solution of calcium chloride with a concentration of 35-40 wt %, after which it is ground. The washing solution after cooling flue gas is fed into the thickener for thickening to produce a filtrate and a cake. A gold sludge with an iron powder and a substituted filtrate, from which sponge copper is produced, are produced from the filtrate. Using hot flue gas, a solution of calcium chloride with a concentration of 35-40 wt % is produced. Gold from the gold sludge is extracted by two chlorination operations and two recovery operations to produce sponge gold, from which the gold ingot is produced. When gold is extracted by chlorination, a gold extraction solution and a cake are produced. The solution is fed to the primary reduction of the gold chlorination sludge. From the cake, silver is recovered, after reduction with hydrazine hydrate, a silver powder is produced, from which a silver ingot is produced.

EFFECT: reagent consumption, the cost price decrease, the degree of complex extraction of valuable metals increases, the level of environmental pollution decreases.

12 cl, 1 dwg, 2 ex