Process for Recovery of Gold from Carbonaceous Ores.
Scheiner-BJ; Lindstrom-RE; Henrie-TA
U S Pat 3 574 600 1971 Apr; :
Gold is recovered from carbonaceous au ores by inhibiting the adsorption of the gold-cyanide complex by carbonaceous impurities. The pretreatment of the ore at <70 deg. C with either an acid-ozone system or with an alkali hypochlorite accomplishes the desired inhibition and allows economic recovery of au from carbonaceous ores. The treatment is carried out by first forming an aqueous slurry of ground ore. A mineral acid is added until a ph of 1 is obtained. Then ozone is bubbled through the acidified slurry. The ore is then filtered from the slurry and treated by conventional cyanidation techniques. Recoveries of 90-96 pct are obtained.
U.S. Pat. 3,574,600; Apr. 13, 1971; Chem. Abstr. 74:129,265X