PROCESS FOR HYDROMETALLURGICAL EXTRACTION OF PRECIOUS METALS

摘要

A description is given of an economically interesting process for the hydrometallurgical extraction of precious metals from materials which contain said precious metals, by the use of thiourea as the reagent in an aqueous acidic medium, in which the leaching solution contains less than 7 g/l, preferably from 0.05 to 2.5 g/l of thiourea, and from 10 to 90% by weight of the thiourea are present in oxidized form, and a redox potential of from 250 to 500 mV prevails in the solution. The adsorption of the precious metal is effected by acidic ion exchangers or by active carbon from the slurry, and after the end of the leaching process said acidic ion exchangers or active carbons are separated from said slurry by means of the correspondingly coarse-meshed fabric.