Melting of Gold-Containing Concentrates with Copper Production Lead Slags

Abstract

Results are presented for a study of the pyrometallurgical treatment of gold-arsenic concentrates with lead osmium-rhenium-containing slags. Conditions are found for preparing alloy ingots consisting of lead, or predominantly of lead sulfide, or both phases. It is shown that with gravitation deposition up to 65–68% osmium is concentrated in 17–25% matte. Gold is almost uniformly distributed over the height of ingots. For industrial application of the results obtained, it is recommended that molten products are poured into a mold heated to 500–550°C, and after natural cooling the lower 25% of alloy is separated for osmium extraction, and gold is extracted from the rest of the alloy by well-known technology. Reduction kinetics are studied for gold, osmium, rhenium, and arsenic. According to kinetic curves, recovery of rhenium in slag proceeds rapidly; osmium recovery ceases in 20–25 min; gold is concentrated in the alloy in 10 min. arsenic is transferred into a gas phase in 10 min, and its concentration in alloy comprises 0.2% on average, and in slags 0.27–0.63%.