Method for treating ferricyanic gold extraction wastewater by using precipitation-electrolytic oxidation synergistic effect

Abstract

Theinvention discloses a method for treating ferricyanic gold extraction wastewater in a gold smelting plant by using a precipitation-electrolytic oxidation synergistic effect. The method comprises the following steps: firstly, introducing the wastewater into a high-position tank or reactor with a stirring function, adding copper chloride or cuprous chloride to perform precipitation reaction, andconverting iron-cyanide ions and a part of free cyanide and zinc cyanide ions into composite precipitation; and introducing supernatant after reaction into an electrolytic cell, and performing electrolytic oxidation reaction with certain voltage by using a titanium plate or stainless steel plate as positive and negative electrodes so as to enable remaining free cyanide, zinc cyanide and copper cyanide ions in the wastewater to be oxidized to nitrogen and carbon dioxide under the synergistic effect of positive electrode oxidation and chlorine gas or hypochlorite generated in the reaction of chlorine ions, and performing electrolytic deposition on copper and zinc at the negative electrode, wherein the wastewater after treatment can return to mineral separation or leaching systems to be circularly used. Copper chloride or cuprous chloride is not only used as a precipitator, but also used as the source of an oxidizer. The method has the characteristics of being simple in treatment process,short in flow process, low in cost and good in treatment effect and has the great significance on deep treatment and comprehensive utilization of cyanide wastewater containing iron ions with high concentration.

Description

technical field

[0001] The invention belongs to the technical field of cyanide-containing wastewater treatment in the metallurgical industry, and in particular relates to a method for treating high-ferricyanide gold extraction wastewater by utilizing the synergistic effect of precipitation and electrolytic oxidation. Background technique

[0002] Due to repeated use, free cyanide and a large amount of copper, iron and zinc cyanide complex ions are enriched in cyanide gold extraction wastewater. Among these ions, copper and zinc cyanide complex ions are weak and healthy complex ions, which are easy to be extracted. Oxidants are oxidized to non-toxic or low-toxic substances, but ferricyanide complex ions are strong complex ions, and it is difficult to effectively treat them by conventional oxidation methods and electrolysis methods. In the present invention, copper chloride is firstly used to precipitate strongly bonded ferricyanide complex ions, and then the synergistic effec...

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