A method for harmless treatment of arsenic-containing slag liquid in biological pre-oxidation-cyanidation gold extraction process of arsenic-containing gold concentrate

Abstract

The invention discloses a harmless treatment method of arsenic-bearing slag liquid of the biological preoxidation-cyanidation gold extracting process of arsenic-bearing gold concentrate. The method includes the steps of firstly, pre-oxidizing the arsenic-bearing gold concentrate with a biological tank leaching process to obtain pre-oxidized ore pulp; secondly, performing solid-liquid separation on the pre-oxidized ore pulp to obtain first supernate and first underflow; thirdly, pre-neutralizing the first supernate, and performing solid-liquid separation on the pre-neutralized first supernate to obtain second supernate and second underflow; fourthly, performing goethite iron precipitation and arsenic fixing on the second supernate for 2-4 hours, and then performing solid-liquid separation to obtain overflow liquid and third underflow, allowing the overflow liquid to enter the biological tank leaching process, allowing part of the third underflow serving as seed crystal to return to the reaction device of the iron precipitation and arsenic fixing, and discharging the rest of third underflow; fifthly, performing cyanidation carbon-in-pulp leaching on the first underflow to obtain ore pulp; sixthly, performing ferric salt aeration arsenic fixing on the ore pulp obtained in the fifth step. The method provides necessary technical support for the environment-friendly, efficient and low-cost development of the arsenic-bearing gold concentrate.

Description

technical field [0001] The invention belongs to the technical field of mineral waste slag treatment, and in particular relates to a method for harmlessly treating arsenic-containing slag liquid of arsenic-containing gold concentrate biological pre-oxidation-cyanidation gold extraction process. Background technique [0002] The two famous Golden Triangles of "Yunnan, Guizhou, Guangxi" and "Shaanxi, Gansu and Sichuan" in my country contain a large amount of low-grade refractory gold concentrates, the gold grade is only 1-6g / t, and it is mainly composed of pyrite and arsenopyrite. The sulfide is wrapped in the gold-loaded sulfide and even exists in the form of lattice gold in the gold-loaded sulfide. At the same time, the particle size of the gold-loaded mineral itself is fine, especially accompanied by a large amount of arsenic and organic carbon. concentrate. This kind of ore is directly cyanided, the gold leaching rate is low, and the amount of sodium cyanide is huge, so it i...

AI Technical Summary

Problems solved by technology

However, due to the slow biological preoxidation process, the gold leaching rate in the cyanide carbon leaching process is mainly used as the main technical index in the biological preoxidation-cyanidation gold extraction process, and to achieve an economically reasonable gold comprehensive recovery rate, gold-loaded sulfide The oxidation rate of the sulfide is generally lower than 100%, and the lowest can reach 50%, that is, there are still most of the gold-loaded sulfides that have not been completely oxidized, resulting in a certain amount of reduced substances in the biological pre-oxidation slag.

At the same time, if the solid-liquid separation of the pre-oxidized pulp is not complete, part of the free As and iron will be carried into the cyanidation system by the pre-oxidized slag, and arsenic-containing precipitates similar to those precipitated by the "lime-iron-salt method" will be formed during the cyanidation alkali adjustment process. The stability of arsenic-containing cyanidation tailings is still poor

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