| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for drastically reducing the discharge amount of waste solutions by selectively removing the phosphite ions accumulated in an electroless nickel plating solution, thereby making the solution reusable for the electroless nickel plating solution. <P>SOLUTION: The method has a step of bringing the aged electroless nickel plating solution into contact with a hydrous metal oxide to incorporate the phosphite ions in the aged solution into the hydrous metal oxide and to remove or decrease the phosphite ions in the aged solution, then of separating the hydrous metal oxide, a step of settling and separating the metal ions in the solution by neutralizing the solution after the separation, a step of cooling the solution after the separation and of separating the deposited sodium sulfate from the solution, and a step of affording the electroless nickel plating solution by replenishing the separated solution with nickel ions, sulfate ions and organic acid ions. <P>COPYRIGHT: (C)2004,JPO |
