Method for leaching low-grade gold in high-arsenic sulfur concentrate acid-making cinder by microorganism preoxidation

Abstract

The invention relates to a method for leaching low-grade gold in high-arsenic sulfur concentrate acid-making cinder by microorganism preoxidation, which has the main contents that bacterium preoxidation is utilized to leach the gold in the high-arsenic sulfur concentrate acid-making cinder, and the technology has the core that by taking various microorganisms, such as Thiobacillus ferrooxidans, sulfolobus and the like, under an acid condition, carbonate, sulfide, irony matter and part of silicate packing the gold are unpacked through oxygen in air, and are oxidized into sulfate, subsulphate or arsenate to achieve the goal of exposing the gold. After the gold is exposed, by taking the dilute sulphuric acid solution of thiourea as a leaching agent, under normal temperature and normal pressure, agitation leaching is carried out on pre-oxidized slag under the condition that the pH value is 1.3-1.8; 70-85 percent of gold is leached, and after solid-liquid separation is ended, a gold-contained solution can be extracted by using a traditional gold extraction process. The method of thiourea gold leaching after bacterium preoxidation has the characteristics that the toxicity is low; the solution in which the gold is removed is easy to treat, can be recycled, and can be produced by using a pollution discharge-free process flow; the gold and silver dissolution velocity is high; and the solution is not sensitive to the harmful impurities of base metals (Cu, As, Sb and Pb).

Description

technical field [0001] This project belongs to the field of metallurgy technology and is a new technology of microbial metallurgy. technical background [0002] The gold in the high-arsenic refractory gold ore is either inlaid with fine-grained gold in arsenopyrite, pyrite, or precipitated between the grains of sulfide minerals, or the gold grains are wrapped in sulfide minerals in the form of insoluble bodies, which is difficult to leach. Usually cyanide leaching after pre-oxidation is the main method. Many domestic institutions and enterprises have achieved certain results. [0003] The arsenic in chemical and smelting waste residues is refractory to treatment. The gold in gold residues is wrapped in carbonates, sulfides, iron compounds, and silicates in complex ways. It is very difficult to leach. Domestic research institutions adopt roasting pretreatment, Wet pressurized oxidation pretreatment, microwave pretreatment cyanide gold leaching, alkali leaching arsenic remov...

AI Technical Summary

Problems solved by technology

The gold in this type of slag is repeatedly wrapped by carbonate, silicate, iron, etc., which is very tightly wrapped and difficult to leaching. The cyanide leaching rate is within 30%, and the recovery value is low. It has become a major issue in the smelting industry. problem

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