Method for realizing short-process and green cyclic utilization of cyanogen-containing barren solution

Abstract

The invention provides a method for realizing short-process and green cyclic utilization of a cyanogen-containing barren solution. Firstly, reduction precipitation is carried out on the cyanogen-containing barren solution so as to enable SCN <-> and Cu<+> to precipitate to be enriched in residues; the purified barren solution is returned to be subjected to cyaniding leaching or follow-up oxidationtreatment to meet the standard to be discharged; then precipitated residues are transferred to be dissolved in alkali liquor through the alkali liquor so that the SCN<-> can be transferred into the alkali liquor to be used for leaching gold extracting from gold ore or cyaniding tailings, preparing thiocyanate and the like, and the dissolving-transferred residues are returned to the reduction precipitation step so as to reduce the consumption of precipitant, namely, copper salt. The method for realizing short-process and green cyclic utilization of the cyanogen-containing barren solution is high in economic benefit, small in pollution, and capable of protecting the environment.

Description

technical field [0001] The invention relates to the technical field of environmental protection, in particular to a short-process green recycling method for cyanogen-containing barren liquid. Background technique [0002] Due to the mature process of gold extraction by cyanidation, low cost and simple operation, more than 80% of gold extraction in the world mainly uses cyanidation, so a large amount of barren solution containing cyanide is produced in the production process. Because the cyanogen-containing poor solution is recycled for a long time, it is difficult to discharge up to the standard, resulting in complex components, high concentrations of total cyanide and thiocyanate, and the sum of the two can reach 1%, or even higher. At the same time, the barren solution containing cyanide also contains valuable metals that can be comprehensively recovered, such as copper and zinc. Moreover, the copper-cyanide complex accumulated in the cyanide-containing barren solution wi...

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Problems solved by technology

For the treatment of high-concentration cyanide-containing barren liquid, the purification method has the disadvantages of using a large amount of chemicals, producing a large amount of sedimentation slag, which cannot be recycled, and high processing costs; while the acidification recovery method has relatively strict process conditions and produces a large amount of precipitation during production. The slag cannot be recycled, and the barren solution after acidification needs to be combined with other treatment methods to meet the standard treatment

Invention patent CN201710292022.3 proposes to use cyanide-containing wastewater to treat and neutralize waste residues to recover valuable metal elements. Although this process can recover a small amount of gold and silver in waste residues; however, copper and zinc elements cannot be fully utilized, and its treatment process is relatively cumbersome and costly

Invention patent CN201410413121.9 proposes to use sulfide precipitation to separate and remove zinc in cyanide-containing barren liquid, acid aeration to obtain copper thiocyanate precipitation to remove copper, and the treated water to be recycled and reused. The resulting product zinc sulfide (<50%) and sulfur The precipitation of cuprous cyanide (<30%) has a low purity, and there is a safety hazard in the removal of copper under acidic conditions

In recent years, direct electrolytic treatment of barren solution containing cyanide has appeared, mainly using the effect of electric field to dissociate metal complexes (Cu(CN)32- and Zn(CN)42-), and metal copper and zinc are deposited on the Cathode recovery, its main disadvantages are low current efficiency and high cost

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