Chemical nickel plating aging liquid reduction regeneration method

Abstract

The invention discloses a chemical nickel plating aging liquid reduction regeneration method. The method comprises the following operation steps that firstly, a recyclable chelating agent is adopted for adsorbing nickel ions in aging liquid, then sulfuric acid is used for desorption, nickel sulfate is prepared and can be returned to a chemical nickel plating production line to be used, then an evaporation concentration process is carried out, sodium sulfate crystals are crystallized and separated, the remaining liquid is subjected to an electrodialysis and electrochemical reduction combined method, phosphite is reduced into hypophosphite, and then the hypophosphite is recycled to the chemical nickel plating production line. According to the method, the comprehensive resource utilization technology is adopted for treating the chemical nickel plating aging liquid, nickel sulfate can be recycled from the aging liquid, hypophosphite can be recycled, resources can be thoroughly utilized, few chemical agents are added, the treatment cost is low, and better use prospects can be brought.

Description

technical field [0001] The invention relates to the utilization of industrial hazardous waste resources and the field of industrial sewage treatment, in particular to a method for reducing and regenerating an electroless nickel plating aging solution. Background technique [0002] The reduction and regeneration of electroless nickel plating aging solution is a supporting method for the reduction, regeneration and recycling of aging solution. The electroless nickel plating process using sodium hypophosphite as the reducing agent has excellent corrosion resistance, wear resistance, uniform coating thickness, and its loading Especially in the electronics industry, the surface treatment of circuit boards is an irreplaceable surface treatment process, but after 4-8 cycles of this process, some substances that have an impact on the coating will inevitably accumulate in the working fluid, such as sub Phosphate, sodium ions, and sulfate ions. The working solution at this time is cal...

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Problems solved by technology

[0002] The reduction and regeneration of electroless nickel plating aging solution is a supporting method for the reduction, regeneration and recycling of aging solution. The electroless nickel plating process using sodium hypophosphite as the reducing agent has excellent corrosion resistance, wear resistance, uniform coating thickness, and its loading Especially in the electronics industry, the surface treatment of circuit boards is an irreplaceable surface treatment process, but after 4-8 cycles of this process, some substances that have an impact on the coating will inevitably accumulate in the working fluid, such as sub Phosphate, sodium ions, and sulfate ions. The working solution at this time is called aging solution. The aging solution contains a large number of environmentally harmful substances, such as heavy metal nickel ions, nutrient phosphorus, ammonia nitrogen, and organic matter. The aging solution is now defined Hazardous wastes can only be processed by companies with hazardous waste qualifications, and the treatment costs are extremely high. The treatment process of hazardous waste treatment companies usually uses chemical methods to precipitate heavy metal nickel, evaporate the aging solution, and use the solid waste formed to fill Buried method of disposal, such a technical treatment plan, actually does not make the resources in the solution be utilized, especially a large amount of phosphate resources are wasted, and the cost is high. We use the resource recycling treatment technology to process the electroless nickel plating aging solution Electrochemical reduction treatment enables the generated phosphite to be reduced to sodium hypophosphite and can be utilized. According to the chemical equation and the phosphorus content in the nickel-phosphorus alloy film, it can be determined that the utilization of phosphorus in the film in the electroless nickel plating process is only 2-5 %, the rest of the phosphorus is in the aging solution. It is too wasteful not to use the phosphorus in the aging solution. With the continuous development of science and technology, people have higher and higher requirements for the manufacturing process of reducing and regenerating the electroless nickel plating aging solution.

[0003] There are certain disadvantages in the reduction and regeneration of the existing electroless nickel plating aging solution. First of all, oxidation-adjustment PH-precipitation is generally used, and a large amount of chemical preparations are added, such as potassium permanganate, hydrogen peroxide, bleaching powder, and sodium hypochlorite. Lime, sodium hydroxide, sulfide, etc., the amount of chemical input is large, and the nickel-containing precipitated solids after treatment have to be landfilled and cannot be reused, which is a waste of resources, and the nickel content of the treated water is far from reaching the level of discharge. Standard, use catalytic reduction method to remove nickel ions, add precious metal palladium chloride, and use reducing agent sodium borohydride to reduce nickel ions to metal nickel. The cost is high, and the concentration of nickel ions in water cannot reach the standard discharge, which is not conducive to people's use. , In addition, only for nickel treatment, there is no comprehensive recycling treatment technology for phosphorus, ammonia nitrogen, and organic matter treatment. Usually, evaporation is used to concentrate. Because the raw water contains high concentrations of ammonia nitrogen, when it evaporates, ammonia nitrogen will evaporate with water. The evaporated water cannot be discharged up to the standard, and the original wastewater contains a large amount of organic acids. When it evaporates to a certain concentration, the water molecules combine with the organic acids to form a sticky hydrate. It is difficult to completely evaporate the water, and the evaporation efficiency is relatively low. The energy consumption is large, the cost is high, and the landfill of the evaporated product will also increase the solidification and stabilizer of nickel metal, which will cost a lot of treatment and bring certain adverse effects to people's use process. Therefore, we propose a A kind of electroless nickel plating aging solution reduction regeneration method

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