A new recycling electroless nickel plating system has been developed using nickel hypophosphite as the source of metallic ions and as a reducing agent. In the system, phosphite ions, which are deleterious for the plating process, are fixed as the precipitate of calcium phosphite. Then they are removed from the solution. During repetitive plating operations, we maintained the plating solution composition and pH as almost constant values. The quantitative change of the reaction products provides theoretical confirmation that the system can be characterized as a ‘zero-emission-type recycling model’.
