Method for environmentally-friendly treatment and recycling of cyanide barren solution

Abstract

The invention relates to a method for environmentally-friendly treatment and recycling of a cyanide barren solution. The method comprises the following steps: carrying out cyanide sedimentation operation on a cyanide-containing barren solution, carrying out cyaniding precipitate conversion, acidifying carbonic acid residue filter cakes, preparing a cyanide sedimentation agent, and feeding back obtained filtrate to a cyanide leaching procedure to achieve the environmentally-friendly treatment and recycling of the cyanide barren solution. By adopting the method provided by the invention, the environmentally-friendly treatment and recycling of the cyanide barren solution are achieved, a process of direct barren solution acidification is avoided, sodium cyanide is in liquid, and thus environment pollution caused by hydrogen cyanide is greatly reduced; the sodium cyanide is recycled and reused with copper and zinc comprehensively, the production cost is lowered, and environment protection requirements on treatment of the cyanide-containing barren solution can be met.

Description

technical field [0001] The invention relates to a process method for treating poor liquid and waste liquid in gold smelting and an environmental protection process, and relates to an environment-friendly treatment and recycling method for poor cyanide liquid. Background technique [0002] In the gold production process, the cyanidation method is mainly used to extract gold and silver. Sodium cyanide (potassium) is the most effective and widely applicable agent for leaching gold and silver at normal temperature and pressure. During the leaching process, due to the accumulation of a large number of impurity ions in the leaching system, the cyanide leachate fatigues after multiple cycles, and the leaching effect is low. Significantly decreased. At present, the most commonly used economical and effective treatment method in China is the acidification method to recover sodium cyanide and reduce the impurity ions in the circulating liquid, so as to maintain the recovery rate of g...

AI Technical Summary

Problems solved by technology

At present, the most commonly used economical and effective treatment method in China is the acidification method to recover sodium cyanide and reduce the impurity ions in the circulating liquid, so as to maintain the recovery rate of gold and silver; a large amount of cyanide in the process of acidification and lye absorption in the process of barren solution treatment Hydrogen gas has caused environmental pollution, and cyanide smelters have been forced to use less or stop using it

[0003] During the acidification process of the lean solution, directly add sulfuric acid to adjust the pH to below 2. The lime in the lean solution not only consumes a large amount of acid, but also the calcium sulfate produced during the reaction affects the copper grade in the filter cake and causes scaling and blockage of the acidification tower and pipelines. The pipeline must be replaced frequently, seriously affecting the normal production

[0004] In the hydrogen cyanide lye absorption stage, due to the low concentration of lye, it takes a long time for multiple cycles of absorption, resulting in gas overflow and affecting the environment. The concentration of sodium cyanide in the absorption liquid is unstable when returning to the leaching process, and the sodium hydroxide has not been reacted. also wasted

[0005] At present, although the simple acidification process of direct acidification and alkalization of the acidification supernatant into cyanidation leaching has been developed, it is still unavoidable that a large amount of hydrogen cyanide is scattered into the air to pollute the environment, and the zinc ions in the barren solution are still present in the barren solution after treatment. Problems with accumulation in leach systems

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