Treatment method of chemical nickel plating waste liquid

Abstract

The invention discloses a treatment method of chemical nickel-plating waste liquid. The treatment method comprises the following steps: S1, nickel precipitation: adding a precipitant into the chemicalnickel-plating waste liquid to precipitate nickel, and filtering and separating the nickel; S2, oxidization: oxidizing hypophosphite and phosphite into orthophosphate by adopting an iron-carbon micro-electrolysis oxidation method,wherein the nickel ions are reduced into elemental nickel through iron, and the Fe<2+> is generated at the same time, then adding hydrogen peroxide to oxidize the Fe<2+>in the waste liquid is oxidized into Fe<3+>, and oxidize the hypophosphite and phosphite into orthophosphate, wherein the Fe<3+> and orthophosphate form an iron phosphate precipitate. The method hasthe advantages that nickel and phosphorus in the chemical nickel plating waste liquid can be separated through one-step treatment, so that the waste liquid reaches the national emission standard, andthe treatment method is simple and low in cost.

Description

technical field [0001] The invention relates to the technical field of waste liquid treatment, more specifically, it relates to a treatment method for electroless nickel plating waste liquid. Background technique [0002] Compared with the traditional electroplating technology, the chemical nickel plating technology has uniform coating thickness and does not need to provide power supply. Even if the plated part is not conductive, it can be nickel plated and has magnetism, etc. Now it is used in diamond micro powder nickel plating, electronic components and aerospace materials. Widely used in other fields. In the electroless nickel plating process, with the consumption of the plating solution, the composition of the plating solution changes and cannot be used normally. In addition to nickel sources such as nickel sulfate and nickel chloride, the nickel plating waste solution also contains a large amount of hypophosphite Complexing agents, organic acid complexing agents and o...

AI Technical Summary

Problems solved by technology

In the electroless nickel plating process, with the consumption of the plating solution, the composition of the plating solution changes and cannot be used normally. In addition to nickel sources such as nickel sulfate and nickel chloride, the nickel plating waste solution also contains a large amount of hypophosphite Complexing agents, organic acid complexing agents and other organic additives with different functions, so the electroless nickel plating waste liquid generally has a high COD, if it is directly discharged, it will cause great pollution to the environment, especially nickel not only pollutes, and caused huge losses

[0003] At present, the treatment process for electroless nickel plating waste liquid is mainly to oxidize the waste liquid with ferrous sulfate and hydrogen peroxide, so that phosphite is oxidized to phosphate, and the organic complex of nickel is decomposed, and nickel ions Lime water is added, and under alkaline conditions, phosphate forms calcium phosphate precipitates. At the same time, nickel forms hydroxides and calcium phosphate precipitates and precipitates together. Although this treatment process can remove nickel and phosphorus, nickel and phosphorus Calcium phosphate precipitates together, to realize the recovery of nickel, nickel and calcium phosphate need to be further separated, the process operation is cumbersome, and the treatment method of nickel and phosphorus is not complete, and the electroless nickel plating waste liquid cannot meet the discharge standard