A kind of environment-friendly chemical stripping agent and stripping method for nickel coating

Abstract

The invention relates to an environmentally-friendly chemical deplating agent for a nickel plating and a deplating method. The deplating agent comprises the components of 30 g / L to 100 g / L of sulfuric acid, 30 g / L to 140 g / L of oxalic acid, 10 g / L to 30 g / L of sodium citrate, 10 g / L to 60 g / L of sodium acetate, 15 g / L to 60 g / L of sodium gluconate, and the balance being water. According to the environmentally-friendly chemical deplating agent, oxalic acid is added based on sulfuric acid, acidity of oxalic acid is not high, and overetching of the nickel plating can be prevented; oxalic acid can provide hydrogen ions used for corroding the plating, and the deplating purpose of the nickel plating can be achieved through only a relatively small amount of sulfuric acid; deplating speed is high, efficiency is high, a deplated stainless steel matrix is smooth in surface, overetching is avoided, and follow-up reutilization and processing are not affected; and oxalate and nickel ions generate nickel oxalate sediment through complexing, nickel is directly sedimented and separated from the system, the follow-up step of recycling nickel metal from deplating waste water is eliminated, nickel oxalate can be directly recycled, and utilization is convenient.

Description

technical field [0001] The invention belongs to the technical field of chemical stripping, and in particular relates to an environment-friendly chemical stripping agent for nickel plating, and also relates to a stripping method using the environment-friendly chemical stripping agent. Background technique [0002] Deplating refers to the process of removing the coating on the surface of the workpiece, which is an inevitable part in the field of electroplating. There are generally two methods of deplating: one is chemical deplating, the deplating parts are soaked in the deplating solution, the principle is to remove the coating by chemical dissolution; the other is electrolytic deplating, the deplating parts are It is placed in the deplating solution for electrolysis, and the principle is to remove the coating by electrochemical method. [0003] Electroless plating Because in the process of workpiece plating, the coating on the surface of the workpiece is completely realized ...

AI Technical Summary

Problems solved by technology

This method is suitable for electroless nickel plating on ordinary carbon steel parts, but sodium m-nitrobenzene sulfonate is highly toxic and is not easy to use in large quantities

The acidic chemical nickel stripping solution generally uses concentrated nitric acid or sulfuric acid as the main oxidant, but concentrated nitric acid produces a large amount of nitrogen oxide gas during the stripping process. Potential safety hazards; the oxidant content used in the acidic chemical nickel stripping solution is high, the corrosion rate is fast, and it is easy to cause over-corrosion of the metal substrate

At the same time, after the existing chemical deplating solution is used, a large amount of deplating wastewater is generated, which requires additional processes for treatment and recovery, which is difficult to process and high in recycling costs