Acid Separation and Heavy Metal Recovery Method in Electroplating Waste Liquid

Abstract

The invention discloses a method for acid separation and heavy metal recovery in an electroplating waste liquor. Acid in the electroplating waste liquor is firstly quickly separated by using an electrodialysis integration technology; acid separation in the electroplating waste liquor can be well achieved by selection of an anionic membrane and a cationic membrane in the electrodialysis process; meanwhile, the heavy metal ions still stay in an electroplating solution; the acidity of the separated acid entering inside a concentration basin can be up to over 4%; the recovered acid can be applied to an electroplating or plated part cleaning procedure; the pH value of the processed electroplating waste liquor can be up to over 3%; valuable heavy metals in the waste liquor can be quickly recovered from a low-acid electroplating waste liquor containing heavy metals by using a hydrogen sulfide gas and a jet process integrated technology; heavy metal ions are participated and recovered in a form of sulfide; the recovery rate of the heavy metal ions can be up to over 95%; the collected sulfide sediment can be used as a raw material to recover the valuable metal; the heavy metal ions in the electroplating waste liquor can be collected by acid separation and recovery; the residual heavy metal ion wastewater is reused or discharged after being processed.

Description

technical field [0001] The invention belongs to the field of chemical environmental protection, and in particular relates to a method for acid separation and heavy metal recovery in electroplating waste liquid. Background technique [0002] The electroplating industry is an indispensable link in the national economy, involving national defense, industry, life and other fields. From the broad categories, it can be divided into metal electroplating and plastic electroplating for parts, so as to achieve the effects of anti-corrosion, beauty, prolonging life, and appearance decoration of workpieces. The wastewater produced by electroplating is highly toxic and harmful to the soil, animal and plant growth. Therefore, it must be strictly treated and discharged after meeting the standards. [0003] The main pollutants in electroplating wastewater are various metal ions, common ones are copper, zinc, cadmium, nickel, manganese, chromium, lead, aluminum, iron, etc.; the second is ac...

AI Technical Summary

Problems solved by technology

[0041] To sum up, due to the high acidity of the electroplating waste solution, the conventional treatment method adopts the neutralization treatment method. The neutralization method not only wastes sulfuric acid resources, but also produces a large amount of neutralization waste residue during the treatment process. The heavy metals in waste slag are of low grade, difficult to recycle and belong to hazardous waste, which must be disposed of safely. Therefore, the development of acid separation and heavy metal recovery in electroplating waste water is of great significance

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