Method and device for purifying and recycling chromium electroplating solution and waste solution thereof

Abstract

The invention discloses a method and a device for purifying and recycling a chromium electroplating solution and a waste solution thereof. The method directionally solves the problem of metal pollutions and comprises the following steps: adopting a purification apparatus to effectively eliminate various harmful metallic impurities such as copper, zinc, nickel, iron and the like; concentrating the solution after the purification; and finally recycling the solution into an electroplating bath, wherein the recycling rate reaches more than 95 percent. Simultaneously, through an automatic control system, the electroplating bath, a recovery tank, the purification apparatus, a concentrating device, an analysis meter and the like are combined together organically to achieve full automatic operation. The method and the device solve the problem that the chromium electroplating solution cannot be recycled in clean production for years in China. The method avoids a large quantity of chromium-containing wastewater discharges, effectively saves additional supplementation of chromic anhydride at the same time, and obtains double produce effects of recycling economy and clean production.

Description

technical field [0001] The invention relates to a method for purifying and recycling an electroplating solution, in particular to a method and a device for purifying and recycling a chromium plating solution and its waste solution. Background technique [0002] Chromic anhydride is a chemical raw material that is widely used in the electroplating industry and has high waste water treatment costs. In the traditional chromic acid chromium plating process, since the chromium plating solution is brought out with the workpiece during production, it is usually necessary to set up 3 to 4 chromium solution recovery tanks behind the electroplating tank to reduce the discharge of chromium-containing wastewater after treatment, although part of the recovery solution Return to the plating tank, but as the concentration of impurities in the recovery tank increases, the recovered chromium solution still needs to be treated before it can be discharged. [0003] For a long time, there is n...

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Problems solved by technology

If the recovered solution is directly replenished back to the chromium plating tank, it will definitely accelerate the accumulation of metal impurities. Once these metal impurities accumulate to a certain level, it will affect the quality of chrome plating, and eventually cause the entire tank solution to be scrapped, and the waste liquid must still be treated before it can be reused. Discharge

[0004] In the past, some people used bisque pot electrolysis to treat the chromium plating bath, hoping to remove various metal impurities, but the results showed that this method was not thorough, and the efficiency was low, and it often caused sulfuric acid in the bath. with Cr 3+ Unbalanced, easily cause chrome plating failure

[0005] In addition, the concentration of chromic acid in the recovery tank of chromium solution is generally low, and the capacity of the chromium plating tank is limited. Even if it is directly reused, the supplementary amount of chromic acid in the plating tank solution is far less than the amount carried out, and still relies on a large amount of extra chromium. Therefore, direct reuse has no obvious economic value and cannot effectively save costs

At the same time, the supplemented recovery solution also brings harmful impurities back to the electroplating tank, causing the bath to be polluted

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