Method for comprehensively recovering valuable metals from electroplating waste mud

Abstract

The invention relates to a method for comprehensively recovering valuable metals from electroplating waste mud. The method comprises the following steps of: leaching valuable metals contained in the electroplating waste mud by dilute sulphuric acid, and filtering and separating out acid-leaching slag and a filtrate; replacing copper ions in the filtrate by metallic iron, and filtering and separating copper powder and a filtrate; adding an alkali solution in the filtrate, adding a polymeric flocculant, controlling the pH value of the solution and reacting, and filtering and separating ferric hydroxide and a filtrate; adding the alkali solution in the filtrate, controlling the pH value of the solution and reacting, and filtering to obtain a chromium precipitate and a filtrate; adding the alkali solution in the filtrate, controlling the pH value of the solution, and converting zinc and nickel in the solution to nickel carbonate and zinc carbonate; and dissolving a nickel-zinc coprecipitate by the alkali solution, and filtering and separating out nickel carbonate and a sodium zincate solution, and concentrating and crystallizing the sodium zincate solution to obtain sodium zincate. The method disclosed by the invention is easy to control process conditions, low in treatment cost, and easy to realize large-scale production; the purpose of comprehensively recovering valuable metals is achieved by implementing harmless and resourceful treatment for the electroplating waste mud; and the recovery rate of copper is greater than 95%.

Description

technical field [0001] The invention relates to an electroplating waste mud treatment technology, in particular to a method for comprehensively recovering valuable metals from electroplating waste mud. Background technique [0002] There are many researches on electroplating sludge treatment process, mainly including acid method and ammonia method. The separation of acid leaching liquid metals in the process of acid treatment of electroplating waste sludge mainly includes solvent extraction of copper and solvent extraction of nickel to realize resource recovery of sludge and obtain copper salts and nickel salts respectively. The recovery conditions are high (such as The pH value of the pickling solution, the phase ratio, the concentration of the extractant, the extraction temperature, the extraction time, the concentration of the stripping solution, the ratio of the stripping solution, the recovery conditions of the stripping solution, etc.). This brings many difficulties t...

AI Technical Summary

Problems solved by technology

This brings many difficulties to small-scale industrial production, it is very difficult to implement, and it is not easy to promote

Ammonia recovery is to use ammonia water to leach copper, nickel, and zinc in the sludge, while iron and chromium that are difficult to handle remain in the solid. The process of ammonia treatment of electroplating waste sludge is lengthy, and ammonia leaching only separates copper, zinc, and nickel. In order to obtain a single metal, other separation methods are needed for separation, and the recovery rate is not high, especially the solid ratio of the ammonia leaching solution is relatively large, resulting in a large equipment volume, increasing equipment investment, and the amount of leached slag is large, and the iron and chromium in the slag are still Harmless or resource-based treatment is required, so the practicability is not good, so it is difficult to popularize and apply