Recovery of precious metals from Gold and Silver drosses

Sample I: Recovery of Gold and Silver from a gold-silver dross assaying 13.68 dwt. Gold/ton and 10.8 oz. Silver/ton was studied by tabling, cyanidation, roasting and cyanidation and flotation. Cyanidation of the roasted dross are recovered 81.0% gold, the entire silver remaining in the residue. Consumption of cyanide was 0.5 lb/ton. Flotation process recovered only 73.7% gold in a concentrate assaying 56.32% gold, which required further treatment for the recovery of gold. Sample II: Another sample reported to be silver dross assayed 22.8% lead, 0.98% copper and 35.8 oz. Silver/ton, and was too fine for gravity treatment. Cyanidation did not yield any satisfactory result. It can therefore best be treated in a lead smelter for recovery of lead as well as of the silver contained in the dross.