Recycling method for acidic etching waste liquid

Abstract

The invention discloses a recycling method for an acidic etching waste liquid. The recycling method for the acidic etching waste liquid comprises the following steps that the pH value range of the acidic etching waste liquid is adjusted to be 1-2; extraction operations are performed on the acidic etching waste liquid by adopting an extracting agent solution, and an oil phase is obtained after still-standing layering; and back extraction operations are performed on the oil phase by adopting a solution containing oxalate ions to obtain copper oxalate. The technical scheme of the recycling methodfor the acidic etching waste liquid is low in operation cost and relatively easy to operate, no toxic waste gases are generated in the operation process, the safety is high, furthermore, no waste liquid and waste residues are discharged in the treatment process, and secondary pollution is not caused; and meanwhile, a product obtained by the recycling method for the acidic etching waste liquid isan ultrafine copper oxalate crystal, the particle size is regular and relatively uniform, the value is high, and hazardous waste transfer qualification is not needed during outward transportation.

Description

technical field [0001] The invention relates to the technical field of waste liquid treatment, in particular to a recycling method for acidic etching waste liquid. Background technique [0002] In related technologies, the recycling methods of acidic etching waste liquid mainly include neutralization method and electrolysis method. Among them, the neutralization method is to add alkali to neutralize the etching waste liquid, so that copper ions are precipitated in the form of copper hydroxide. After pressure filtration, the copper sludge is sent to the smelter to be smelted into elemental copper. This method not only wastes a lot of alkali, but also produces a large amount of waste water. At the same time, the value of the copper sludge after pressure filtration is low. Although the electrolysis method can produce valuable electrolytic copper, due to the need to add electrolytic additives during the electrolysis process, the residual additives will affect the subsequent reus...

AI Technical Summary

Problems solved by technology

[0002] In related technologies, the recycling methods of acidic etching waste liquid mainly include neutralization method and electrolysis method. Among them, the neutralization method is to add alkali to neutralize the etching waste liquid, so that copper ions are precipitated in the form of copper hydroxide. After pressure filtration, it becomes copper sludge and is sent to the smelter to be smelted into elemental copper. This method not only wastes a lot of alkali, but also produces a large amount of waste water. At the same time, the value of copper sludge after pressure filtration is low.

Although the electrolysis method can produce valuable electrolytic copper, due to the need to add electrolytic additives during the electrolysis process, the residual additives will affect the subsequent reuse of the regeneration solution. Chlorine