Development of a Combined Technology for Producing Base Gold Alloy from Waste of Different Types

Transbaikalia is the oldest mining region of Russia where the first domestic gold was mined; therefore, hundreds of millions of tons of waste have been accumulated, including the dumps of the Catherine Silver Smelters. The material composition of the gold-containing waste was studied. A combined technology for producing base gold alloy from waste of various types (cutoff-grade ore, mature tailings, fresh tailings) has been developed, including: pre-concentration of cutoff-grade ore to remove 40% of the dump rock; grinding for releasing mineral grains of gold–sulfide associations in a mill, adding litharge to intensify the process; vat cyanide leaching (stage I) of the jointly crushed pay fraction and flotation tailings with ozone bubbling for additional oxidation of refractory minerals; heap cyanide leaching of pelletized mature tailings with filter cakes (stage II), adding hydrogen-peroxide solution and surfactants that accelerate the wetting of pellets and the capillary invasion of the leaching solution into the heap until it is completely saturated. In the experiments, the average recovery (\({\upvarepsilon }_{\mathrm{av}}^{\mathrm{Au}}\) = 88.15%) for the two stages of leaching was determined, and base gold ingots (alloy) with a gold content of at least 10% were produced.