Method for recovering, treating and recycling valuable metal in contaminated acid

Abstract

The invention discloses a method for recovering, treating and recycling valuable metal in contaminated acid, which comprises the following steps: adding lime and coagulant into contaminated acid, and separating through a precipitation membrane to obtain concentrated water and permeated water; adding lime, coagulant, sodium hypochlorite and iron chloride into the concentrated water, performing solid-liquid separation, adding sodium sulfide and coagulant into the separated supernatant, performing precipitate solid-liquid separation on the supernatant, using the separated copper sulfide waste slag for ingredient smelting, and combining the separated liquid and the permeated water; and adding lime and coagulant in the combined wastewater, then performing precipitate solid-liquid separation, adding sodium hypochlorite, iron chloride and coagulant into the separated liquid, and finally performing precipitate solid-liquid separation to obtain wastewater for recycling or environmentally acceptable discharge. According to the invention, pretreated contaminated acid is subjected to nanofiltration treatment, sulfurization recovery and advanced treatment, so that the valuable metal in the wastewater is effectively recovered, the generation of hazardous wastes is reduced, the hardness of the effluent water after treatment is low, and the effluent water can be recycled or discharged according to standards.

Description

technical field [0001] The invention relates to a method for recovering, treating and reusing valuable metals in sewage acid, which is used for the recovery, treatment and reuse of valuable metals in sewage acid of nonferrous metal smelting, and is especially suitable for recycling valuable metals in sewage acid of copper smelting industry and processing for reuse. Background technique [0002] In the non-ferrous metal smelting process, high-concentration sulfur dioxide flue gas is sent to the acid system after dust collection. Flue gas needs to be washed and purified before acid production, so as to produce dirty acid containing about 10% sulfuric acid. During the washing process, pollutants such as arsenic, cadmium, copper, and fluorine in the flue gas and dust enter the sewage acid, forming highly acidic wastewater containing arsenic, cadmium, copper, and fluorine. At present, lime neutralization method and lime-iron salt method are generally used in existing technologi...

AI Technical Summary

Problems solved by technology

[0003] The present invention proposes a method for recovering and reusing valuable metals in sewage acid to solve the problems of low recovery rate of valuable metals, large amount of waste residue and non-recyclable wastewater after treatment in the existing sewage acid treatment technology. question

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