Comprehensive recovery method of sulfuric-acid residue containing gold and silver

Abstract

The invention discloses a comprehensive recovery method of sulfuric-acid residue containing gold and silver. The method comprises the steps of: firstly, mixing gold and silver sulfuric-acid residue, reductive pulverized coal and bentonite and pelletizing; then carrying out direct reduction on dry pellets for 10-40 minutes inside a reduction furnace at the reduction temperature of 1100-1300 DEG C; carrying out water quenching and cooling on the reduced metal pellets and then carrying out grinding and magnetic separation, wherein tailings obtained after magnetic separation can be used as cement packing and the iron ore concentrate obtained after magnetic separation contains gold and silver; dissolving iron ore concentrate by adopting dilute sulphuric acid or diluted hydrochloric acid, wherein gold and silver cannot be dissolved and serve as sediments to be enriched in the residues; and directly conveying the gathered the residues to a smelting procedure. By adopting the technique, comprehensive recovery and utilization of gold, silver and iron in the sulfuric-acid residue containing gold and silver can be achieved; the yields of gold, silver and iron are high; the recovery rate of gold is 100%; the recovery rate of silver is over 95%; the recovery rate of iron is over 85%; the valuable elements, such as gold, silver and iron in the sulfuric-acid residue can be extracted to the maximal extent; and good economic benefit and social benefit are achieved.

Description

technical field [0001] The invention relates to a technology for treating pyrite slag, in particular to a method for comprehensive recovery of gold and silver-containing sulfuric acid slag. Background technique [0002] Pyrite slag is the waste slag discharged during the production of sulfuric acid, called sulfuric acid slag. The waste slag produced per ton of sulfuric acid depends on the sulfur content of pyrite, generally 0.8 to 1.5 tons. At present, the use of sulfuric acid slag mainly has several aspects: as a baking aid for cement production, brick making, production of iron oxide pigments, preparation of ferrous sulfate, preparation of polyferric sulfate, preparation of sponge iron, recovery of precious metals, production of iron concentrate powder, etc. . [0003] For sulfuric acid slag rich in gold, silver, copper, cobalt and other rare and precious metals, most of the processes used are direct cyanide leaching to extract gold and silver, magnetization roasting or d...

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Problems solved by technology

[0014] The gold recovery rate is low; there is no recovery of a large amount of iron in the sulfuric acid slag; the wet process is adopted, and the direct flotation process needs to grind the sulfuric acid slag to -0.045mm, accounting for 90.68%. The grinding cost is high, and the chemicals used There are BG-1 collectors, PH regulators, foaming agents, etc. The consumption of chemicals is relatively large, and the corresponding cost is relatively high; the use of cyanide method, although the treatment measures are adopted, will still cause relatively large pollution to the environment. Difficult to handle

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