Method for recovering nickel resource in waste acid system

Abstract

The invention discloses a method for recovering nickel resource in a waste acid system. The method comprises the following steps: (1) adding a lime neutralizer into waste acid, adjusting the pH value to 4.0-4.5, reacting for 10-30 minutes, and carrying out filter pressing to obtain filtrate A and filter residues A; (2) adding a strong alkali neutralizer into the filtrate A, adjusting the pH value to 5.5-8.5, reacting for 30-60 minutes, adding a carbonate neutralizer, and adjusting the pH value to 9.0-11.0 to obtain a mixed solution; (3) adding a heavy metal remover into the mixed solution, stirring, and carrying out filter pressing to obtain filtrate B and nickel mud; and (4) drying and dehydrating the nickel mud to obtain a nickel product. According to the method, three-step neutralization is carried out by using different neutralizers in sequence, the recovery rate of nickel in the waste acid and the purity of nickel products can be effectively improved, pollution to the environment is reduced, the process of the recovery method is simple, the price of the used neutralizers is low, and the cost can be greatly reduced.

Description

technical field [0001] The invention relates to the technical field of sewage treatment, in particular to a method for recovering nickel resources in a waste acid system. Background technique [0002] Nickel is a carcinogenic heavy metal, but it is a relatively expensive metal resource, and its price is 2-4 times that of copper. With the accelerated development of the economy, my country's demand for nickel is also increasing. Since 2005, my country has become the country with the largest nickel consumption in the world, and currently 65% ​​of the world's nickel is used to produce stainless steel. With the rapid development of the stainless steel industry, the demand for nickel in the world is also increasing, and the supply is in short supply. [0003] At present, in the process of processing nickel-chromium stainless steel, pickling treatment is required to remove the oxide layer on the surface of stainless steel, resulting in a large amount of nickel-containing waste ac...

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Problems solved by technology

[0004] Nickel-containing waste acid is highly difficult and difficult to degrade toxic wastewater. At present, the treatment processes for such waste acid mainly include chemical precipitation method, ion exchange method, electrodialysis method and roasting method. Although the recovery rate of electrodialysis method and ion exchange method is High but high power consumption, high cost, and large investment required; the roasting method is likely to shorten the life of the equipment due to high temperature operation, and the acid gas and dust generated by the high temperature will cause secondary pollution to air and environmental pollution; chemical precipitation The method has the advantages of good treatment effect, less investment, and easy operation, but the amount of sludge produced by the chemical precipitation method is large, dehydration is difficult, and the content of heavy metals in the sludge is low, and the recovery rate of heavy metals is low.

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