LLC “Novoangarsky Dressing Plant”, Novoangarsk, Russia:

I. I. Evtushevich, Chief Dresser
Ch. T. Dzgoev, Deputy Head of Moscow Representative Office

JSC “Irgiredmet”, Irkutsk, Russia:
Yu. E. Emelyanov, Leading Researcher
A. V. Epiforov, Senior Researcher, e-mail: epiforov@irgiredmet.ru

Autoclave oxidation is one of modern methods of refractory gold-bearing raw materials opening. This technology allows the sulfide destruction and arsenic transfer in poorly-soluble compounds, and sulfur and non-ferrous metals transfer in sulfate form without any significant harm to environment. The disadvantages of this technology are low extraction of gold during “double refractory” concentrate processing (because of so-called preg-robbing) and low silver extraction (10–30%) (because of the cyanidation-resistant silver jarosite formation in oxidation process). For the purpose of defect elimination, there was designed the combined autoclavepyrometallurgical technology, including the autoclave oxidation of sulfide goldbearing concentrate (jointly or separately) with lead or lead-zinc concentrate at the temperature of 220 ^oC and partial pressure of oxygen (0.7 MPa). Transfer of the basic mass of sulfur and arsenic in solution requires the conditioning of oxidized pulp before filtration at the temperature of 95 ^oC during 2 hours. Solid residues of autoclave oxidation are processed by alkaline for the removal of sulfur and arsenic residues with further reduction smelting of hydrometallurgical processing products with lead bullion obtaining. Later on, grade bullion and gold-silver foam are obtained from lead bullion. The foam is processed with gold-silver alloy obtaining. The offered technology is suitable for a wide spectrum of polymetallic ore and anthropogenic raw materials and makes a small impact on environment.

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