Method for reducing metal consumption during recovery of gold in thiosulfate gold leaching liquid by replacement method

Abstract

The invention discloses a method for reducing metal consumption during recovery of gold in thiosulfate gold leaching liquid through a replacement method, and belongs to the field of precious metal recovery of hydrometallurgy. The method comprises the steps that reduction potential is applied to the copper-ammonia-containing thiosulfate gold leaching solution through a three-electrode system, the applied potential is controlled to be within the range of 0.14 V or below, the open-circuit potential of the solution is reduced to be 0.1 V or below, a working electrode, an auxiliary electrode and a reference electrode are arranged in three areas which are physically and spatially isolated, and after the open-circuit potential of the solution is reduced to be 0.1 V, the copper-ammonia-containing thiosulfate gold leaching solution is obtained. And a proper amount of zinc powder, copper powder and aluminum powder are added for a reduction reaction, and the reduced solution is filtered, pickled and purified to obtain pure gold. According to the method, the oxidation-reduction potential of the gold leaching liquid is regulated and controlled through an electrochemical control method, the consumption of metal used for replacement can be reduced by 80% or above, and the solution obtained after solid-liquid separation can still return to the leaching stage to be recycled.

Description

technical field [0001] The invention relates to a method for reducing metal consumption when recovering gold in a thiosulfate gold leaching solution by a replacement method, and belongs to the fields of hydrometallurgy and precious metal recovery. Background technique [0002] Among the wet extraction processes of gold, the thiosulfate gold leaching method is the most promising non-toxic and environmentally friendly process to replace the cyanide method. However, Au(S) was recovered from the leaching solution 2 O 3 ) 2 3- still challenging. The activated carbon adsorption method, which is widely used in the cyanidation process, has no effect in the thiosulfate gold leaching process. This phenomenon is attributed to the Au(S 2 O 3 ) 2 3- The affinity with activated carbon is not enough. In order to improve the effect of activated carbon on Au(S 2 O 3 ) 2 3- In recent years, scholars have studied the method of modifying activated carbon loaded with different organ...

AI Technical Summary

Problems solved by technology

The excessive consumption of reduction is not only easy to dissolve these reagents in the ammonium thiosulfate solution, but also inseparable from the extraction process of gold; the dissolution process of gold has the participation of corresponding oxidants, such as oxygen and sulfur in the cyanide leaching gold system. Cu in sulfosulfate leaching gold system 2+ , Fe in thiourea gold leaching system 3+ ; As long as the oxidizing agent is present, the reduced gold element will dissolve again, thus greatly increasing the consumption of metal precipitating agent

[0004] The method of adding fluoride or EDTA can weaken the influence of oxidants because these anions can form complexes with ferric ions or divalent copper ions, which reduces the redox potential of the solution; but this method makes The leachate after filtration and separation cannot be returned to the leaching stage for recycling

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