Method for treating cyanide-containing wastewater of gold production enterprises

Abstract

The invention discloses a method for treating cyanide-containing wastewater of gold production enterprises. The method comprises four steps of electrochemical treatment, coagulating sedimentation treatment, ozonation treatment and biological active carbon treatment. Specifically, the method comprises the following steps: firstly, removing easily treated cyanide by adopting an electrochemical treatment process, and performing coagulating sedimentation on the treated wastewater by adding a zinc sulfate solution and a coagulant to remove metal cyanide complexes and heavy metal ions in the wastewater; secondly, introducing ozone into supernatant liquid, and oxidizing to remove pollutants such as residual difficultly treated cyanide, thiocyanate and the like in the wastewater; finally, removing pollutants difficultly removed by a chemical process in the wastewater by adopting a biological and physical adsorption process through a biological active carbon treatment system. The method is used for deeply treating the cyanide-containing wastewater, has a good treatment effect and is high in treatment efficiency and simple in process; the treated wastewater can return to a production process to be used as recycled water or to be discharged by standard.

Description

technical field [0001] The invention relates to a pollutant treatment method in the field of environmental protection, in particular to a treatment method for cyanide-containing wastewater of a gold production enterprise. Background technique [0002] Due to the use of cyanide in the process of gold mining and smelting, gold production enterprises will produce a large amount of cyanide-containing wastewater. This part of cyanide-containing wastewater not only contains a certain amount of highly toxic cyanide, but also contains thiocyanate and copper, zinc , lead and other heavy metal ions, if not effectively dealt with, will produce major environmental hazards. At present, the methods commonly used at home and abroad to treat cyanide-containing wastewater include acidification recovery method, alkali chlorine method, Inco method, sulfur dioxide method, etc. Although a certain amount of cyanide can be recovered by using acidification recovery method, due to the incomplete rec...

AI Technical Summary

Problems solved by technology

[0002] Due to the use of cyanide in the process of gold mining and smelting, gold production enterprises will produce a large amount of cyanide-containing wastewater. This part of cyanide-containing wastewater not only contains a certain amount of highly toxic cyanide, but also contains thiocyanate and copper, zinc , lead and other heavy metal ions, if not effectively treated, will cause major environmental hazards

At present, the methods commonly used at home and abroad to treat cyanide-containing wastewater include acidification recovery method, alkali chlorine method, Inco method, sulfur dioxide method, etc. Although a certain amount of cyanide can be recovered by using acidification recovery method, due to the incomplete recovery of cyanide, the waste water A certain amount of cyanide will remain in the medium, and at the same time, thiocyanate and some heavy metal ions have not been effectively removed

After the alkali chlorine treatment, a large amount of residual chlorine will remain, and ClCN products will be produced, causing secondary pollution problems. At the same time, heavy metal ions such as copper, zinc, and lead in the wastewater have not been effectively treated.

Although the Inco method and the sulfur dioxide method can make the treatment of cyanide meet the standard, the thiocyanate in the wastewater cannot be treated. In addition, there are many waste residues generated during the treatment of heavy metals, which is likely to cause secondary pollution

Therefore, there is still a lack of ideal methods for the treatment of cyanide-containing wastewater. If this problem can be solved, it will be of great significance to the development of my country's gold production and environmental protection.