A method for treating cyanide-containing wastewater from gold cyanide enterprises

Abstract

The invention discloses a method for treating cyanide-containing wastewater in gold cyaniding enterprises. The method comprises the four steps of electrochemical treatment, chemical oxidation treatment, coagulating sedimentation treatment and biological activated carbon treatment. When the cyanide-containing wastewater is treated, cyanide is electrolyzed by adopting the electrochemical treatment method; coagulating sedimentation is carried out by adding a coagulating agent, and heavy metal pollutants in wastewater can be removed; precipitated wastewater is oxidized by adding a chemical reagent; and finally, pollutants which are hardly removed from wastewater by a chemical method are removed by adopting a biological and physical adsorption method through a biological activated carbon treatment system. According to the method, the four steps are combined together according to the characteristics of complex and hardly treated pollutants in cyanide-containing wastewater of gold production enterprises, and are synergized to carry out deep treatment on the cyanide-containing wastewater of gold production enterprises. The method has the advantages of good treatment effect, high treatment efficiency, stable system operation and simple process flow, and can easily realize industrial application, and the treated wastewater can be returned to a production process flow to be used as reclaimed water or discharged with standard level.

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 cyanidation enterprise. Background technique [0002] Gold cyanide enterprises will produce a large amount of cyanide-containing wastewater due to the use of cyanide gold extraction process in the process of gold beneficiation. This part of cyanide-containing wastewater not only contains a certain amount of highly toxic cyanide, but also contains thiocyanate and copper Heavy metal ions such as zinc, lead, etc., 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 in...

AI Technical Summary

Problems solved by technology

[0002] Gold cyanide enterprises will produce a large amount of cyanide-containing wastewater due to the use of cyanide gold extraction process in the process of gold beneficiation. This part of cyanide-containing wastewater not only contains a certain amount of highly toxic cyanide, but also contains thiocyanate and copper Heavy metal ions such as zinc, lead, etc., 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 sustainable development of my country's gold industry and the environmental protection of gold mines.