Method for recovering valuable metals from electroplating sludge

Abstract

The invention relates the recovering metal method from electroplating sludge, comprising the following step: 1 using diluted acid to extract metal from electroplating sludge, filtering and separating, getting pickle liquor; 2 setting the copper from pickle liquor with sulphide at 85-100Deg.C, filtering and separating, getting cupric sulfide and deposition mother liquid; 3 adding 5-20% queous alkali into deposition mother liquid, and controlling the PH between 5.0 and 6.0, setting chromium and aluminium, filtering and getting the chromium-aluminium slag and the mother liquid containing iron, zinc and nickel. The method has the advantages of good technology versatility, easy controlling, simple equipment and low cost.

Description

(1) Technical field [0001] The invention relates to a method for recovering valuable metals from electroplating sludge. (2) Background technology [0002] The existing electroplating sludge treatment process mainly focuses on harmless treatment, although some of them also comprehensively consider resource utilization and harmless treatment. For example, ammonia recovery uses ammonia water to leach Cu, Ni, and Zn in the sludge. However, iron and chromium, which are difficult to handle, remain in the solid, and the ammonia treatment process is lengthy. The ammonia leaching only separates copper, zinc, and nickel. To obtain a single metal, other separation methods are required, especially ammonia immersion liquid-solid comparison. Large, up to 12:1, resulting in large equipment volume, increased equipment investment, and a large amount of leached slag, some accounting for more than 50% of the initial sludge, and the iron and chromium in the slag must be treated in a harmless or...

AI Technical Summary

Problems solved by technology

[0002] The existing electroplating sludge treatment process mainly focuses on harmless treatment, although some of them also comprehensively consider resource utilization and harmless treatment. For example, ammonia recovery uses ammonia water to leach Cu, Ni, and Zn in the sludge. However, iron and chromium, which are difficult to handle, remain in the solid, and the ammonia treatment process is lengthy. The ammonia leaching only separates copper, zinc, and nickel. To obtain a single metal, other separation methods are required, especially ammonia immersion liquid-solid comparison. Large, up to 12:1, resulting in large equipment volume, increased equipment investment, and a large amount of leached slag, some accounting for more than 50% of the initial sludge, and the iron and chromium in the slag must be treated in a harmless or resourceful manner.

Acid recovery usually removes iron and chromium in the leaching solution by co-precipitation, which is likely to cause co-precipitation of valuable heavy metal ions such as nickel and zinc for electroplating sludge with high content of iron and chromium, thereby reducing its recovery rate. A large amount of iron-chromium slag needs further harmless treatment or recycling

Therefore, the practicability is not good enough, so it is difficult to popularize and apply