PROBLEM TO BE SOLVED: To provide a method for cleaning an electroless nickel plating waste liquid and a method for recovering nickel and a phosphate and recycling them using simple apparatus by a low-cost and effective process by eliminating a problem in the conventional oxidation method for cleaning the electroless nickel plating waste liquid. SOLUTION: The method for cleaning an electroless nickel plating waste liquid comprises: a first step where nickel ions are separated from an electroless nickel plating waste liquid; a second step where hypophosphoric acid ions in a separate liquid obtained in the first step are oxidized into phosphorous acid ions by an oxidation catalyst; a third step where the phosphorous acid ions obtained in the second step are oxidized into orthophosphoric acid ions by an oxidation catalyst; and a fourth step where the orthophosphoric acid ions obtained in the third step are converted into a phosphate, which is subjected to filtering/separating, thus is cleaned into a waste liquid having a phosphorous concentration of ≤16 mg//l, and the phosphoric acid is recovered as a phosphate. COPYRIGHT: (C)2010,JPO&INPIT

Methods for oxidizing hypophosphoric acid ion and phosphorous acid ion, method for cleaning electroless nickel plating waste liquid, and method for recycling phosphate

The invention discloses a method for treating a nickel immersing solution. The method includes the steps that (1) the nickel immersing solution and lime milk are subjected to mixed precipitation, so that a liquid-solid mixture is obtained; (2) the liquid-solid mixture is thickened, so that overflow containing nickelous hydroxide sediment and underflow containing calcium sulfate are obtained; and (3) the overflow containing nickelous hydroxide sediment is filtered, so that nickelous hydroxide and filtrate are obtained. According to the method, the lime milk serves as a precipitator, and an existing nickel immersing process is simplified. Compared with an existing nickel immersing technology, the production cost of nickel per ton is not less than 2000 yuan, meanwhile, the direct recovery rate of the nickel can reach 96%, the effect is obvious, large-flow treatment can be achieved, and the method for treating the nickel immersing solution is suitable for industrial production and application.

Method for treating nickel immersing solution

The invention provides a method for recycling phosphorous electroless nickel plating solution element in a wet process of surface treatment. The method comprises the following steps of: performing chlorine removal treatment on the plating solution or washing solution to remove chlorine by utilizing a carbon-fiber filter; carrying out separating by using a separation device; carrying out adsorption treatment by using an adsorption device with resin to adsorb residual impurities and produce recycled washing solution at a deionized water level; carrying out sedimentation and separation by using a sedimentation and separation device so as to remove a heavy metal catalyst and produce precipitated and separated recycled solution; purifying by using a purification device to produce calcium-contained solution and acid-contained recycled solution; and mixing by using a mixing device, mixing the recycled washing solution, the precipitated and separated recycled solution and the acid-contained recycled solution to obtain recyclable regenerated solution. Therefore, according to the method provided by the invention, the recycling of the nickel resource can be improved and waste reduction and zero discharge can be achieved.

Method for recycling phosphorous electroless nickel plating solution element in wet process of surface treatment

PROBLEM TO BE SOLVED: To provide a treatment method capable of efficiently separating and removing Ni ions, a phosphite component and organic acids by a simple operation from an aged electroless Ni plating solution. SOLUTION: This treatment method comprises a process 1 in which Ni ions in an aged solution are separated and recovered as Ni metal through an electroless plating reaction caused by bringing an aged electroless Ni plating solution into contact with Ni powder, a process 2 in which the separated host solution in the process 1 is brought into contact with a chelate resin to absorb and separate residual Ni ions, a process 3 in which a dissolved phosphite component is separated and recovered as Ca phosphite by reacting gypsum or mineral acid and hydrated lime with the separated solution in the process 2, a process 4 in which the residual phosphite component is oxidized and decomposed in the presence of an oxidant into a phosphoric acid component and separated and recovered as Ca phosphate by a reaction with a Ca salt, and a process 5 in which organic substances in the separated solution in the process 4 are removed by an activated sludge process.

Horikawa Takeshi

Papers

Method for treating aged electroless nickel plating solution