Gold concentrate roasting and enrichment method

Henan and Shaanxi Qinling Mountains small mining gold-containing quartz vein gold sulphides, generally produce mixed concentrate. Its grade gold is 98.89g/t, silver 150g/t, copper 1.45%, lead 2.5%, zinc 1.2%, sulfur 26%, iron 31%. For this complex gold concentrate, the former National Gold Bureau built the Zhongyuan Smelter in Sanmenxia City, specializing in the smelting of gold concentrate produced in the gold mines of Henan and Shaanxi. The processing capacity is 250t/d, and comprehensive recovery of gold, silver, copper, lead and sulfur It was completed and put into production in 1991.

The gold concentrate is subjected to sulphation roasting in a vertical boiling furnace, and the flue gas enters the sulphuric acid system. The calcination was leached for 1 h at a temperature of 70 ° C, a slurry concentration of 40%, and a sulfuric acid content of 15 g / L. The liquid containing copper was 13.19 g/L by liquid-solid separation, and the sponge copper containing 75% of copper was directly sold by using iron. After the copper was immersed in the slurry to a liquid-solid ratio of 2.9, salt and hydrochloric acid were added, and the pH was immersed at 50 ° C for 5 h. The leaching solution obtained by solid-liquid separation contained 9.51 g/L of lead and 34.2 mg/L of silver. Iron 12.72%. After heating to 90 ° C, it was replaced with iron powder to obtain a silver sponge lead. The leaching residue after the lead removal was again adjusted to a liquid-solid ratio of 2.9. The leaching time was 36h under the condition of sodium cyanide concentration of 0.08% and pH=10.5～11. After solid-liquid separation, the gold was replaced by zinc powder. The gold leaching rate was 98.17% and the copper recovery rate was 84.15%. The lead recovery rate was 89.10%.