High-efficiency environment-friendly acid-mixed plating removal liquor

Abstract

The invention relates to a high-efficiency environmental-friendly utilization method for acid-mixed removal plating liquid, which comprises: putting the liquid into reaction kettle, adding Na2CO3 or NaOH to neutralize free HNO3 and H2SO4, separating the micro impurity of iron, chrome and aluminum as hydroxide precipitate, and controlling the pH value; filtering, adding Na2CO3 saturated solution for neutralization, and adding a little CaCO3 to deposit copper as CuSO4 and excessive SO4- as CaSO4; filtering, preparing CuSO4 with slag and H2SO4, separating CuS and ZnS with added H2S gas; filtering again, adding Na2CO3 or NaHCO3 to deposit the nickel as basic nickel carbonate or nickel carbonate; filtering, preparing nickel sulfate with slag and sulfuric acid, and preparing NaNO3 product as normal technique. This invention makes full use of the sewage.

Description

technical field [0001] The invention relates to an efficient and environmentally friendly utilization method of a highly acidic deplating solution, in particular to an efficient and environmentally friendly utilization method of a nitric acid and sulfuric acid mixed acid deplating solution. Background technique [0002] The main components of the mixed acid are more than 80% nitric acid and less than 20% sulfuric acid. In the electroplating industry, because sometimes the treated coating is not ideal, it is necessary to use mixed acid to remove the coating and re-plate it. In this process, waste liquid will be produced, and It is the mixed acid stripping solution. The mixed acid stripping solution mainly contains copper, nickel, sulfuric acid and a large amount of free nitric acid, and the free nitric acid accounts for more than 50% (G / V). The mixed acid stripping solution also contains trace amounts of iron, chromium, aluminum, zinc and other components . At present, the ...

AI Technical Summary

Problems solved by technology

At present, the treatment and utilization method of this waste liquid is mainly to evaporate nitric acid by direct heating, and then add a small amount of sulfuric acid to make copper sulfate, nickel sulfate crude product or make mixed oxides, but in the current treatment method, although The mixed acid stripping solution can be treated, but the valuable components of the mixed acid stripping solution cannot be fully utilized. Only sulfuric acid, copper, and nickel can be processed into valuable products, and the rest of the components are discharged as waste. , on the one hand, this increases the production cost, on the other hand, it also causes a lot of waste of resources and environmental pollution. If the large amount of waste water and waste gas produced is treated independently, the treatment cost will be increased to a large extent. The treatment will cause secondary pollution, which cannot achieve environmental protection

People have been studying ways to improve the full utilization of valuable components in the mixed acid stripping bath, avoiding waste of resources, turning waste into treasure, eliminating pollution, and truly realizing circular economic utilization, but this has always been a problem that is difficult to solve

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