Acoustic cavitation complex-based cyanidation gold extraction waste water treatment and recycling system

Abstract

The invention relates to an acoustic cavitation complex-based cyanidation gold extraction waste water treatment and recycling system which comprises three stages of acoustic cavitation treatment systems, wherein a primary acoustic cavitation treatment system consists of a primary acoustic cavitation treatment tank, a zinc sulfate addition unit and a filtering device I, and is used for performing precipitation reaction of cyanidation gold extraction waste water, and converting copper, ferrum and cyanide in the cyanidation gold extraction waste water into a precipitate I; a secondary acoustic cavitation treatment system consists of a secondary acoustic cavitation treatment tank, a diluted sulfuric acid addition unit, a filtering device II and an alkaline liquid absorption unit, and is used for separating copper, ferrum and zinc in the precipitate I generated by the primary acoustic cavitation treatment system, and converting cyanide into hydrogen cyanide and recycling; a tertiary acoustic cavitation treatment system consists of a tertiary acoustic cavitation treatment tank and a hydrogen peroxide addition unit, and is used for treating cyanide-containing waste water to achieve the emission standard. Heavy metals of copper, ferrum, zinc and the like in the waste water can be separated from cyanidation gold extraction waste water, hydrogen cyanide gas is recovered to generate NaCN solution which can return to a leaching system for recycling.

Description

technical field [0001] The invention relates to a treatment system for gold extraction wastewater, in particular to a treatment and recycling system for cyanidation gold extraction wastewater based on sonochemical compounding. Background technique [0002] Cyanide gold extraction is a traditional process of gold extraction, and it is also the most important process of gold leaching at present. Since gold ore contains not only gold and silver precious metals, but also associated copper, zinc, iron, sulfur and other elements, the wastewater generated during the cyanide gold extraction process contains free cyanide CN - , copper cyanide complex Cu(CN) 4 3- 、Cu(CN) 3 2- or Cu(CN) 2 - , Zinc cyanide complex Zn(CN) 4 2- , ferricyanide complex Fe(CN) 6 4- or Fe(CN) 6 3- and thiocyanate SCN - etc., while containing a small amount of gold cyanide complex Au(CN) 2 - , silver cyanide complex Ag(CN) 2 - . It can be seen that the composition of wastewater from cyanidati...

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Problems solved by technology

In addition, gold extraction wastewater contains metal elements such as copper and iron. If it is discharged directly without treatment, it will also cause great damage to the ecological environment.

[0003] If the cyanide wastewater is not discharged for a long time or the metals in it are not separated, it will be recycled in the cyanide gold extraction system for many times. Recycling, the metal complexes in the wastewater will gradually accumulate, resulting in a large consumption of cyanide during leaching, and a decrease in leaching efficiency. Especially when the content of copper minerals in the ore is high, the cyanide wastewater produced will contain more With high concentration of copper, the consumption of cyanide will be greater when returning to leaching, and the cost of leaching will increase; however, when the water in the system reaches saturation, the normal operation of the enterprise will be affected if no external defecation is performed at this time

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