| 摘要 |
PURPOSE:To reutilize plating soln. by circulating it as it is to the plating process, by heat treating a material to be plated in the presence of aqueous soln. contg. Sn powder and ions so as to plate the material with Sn. CONSTITUTION:Metals whose normal electrode potential is nobler than that of Sn, e.g., gold, silver, platinum, copper, and carbonaceous material, metallic carbide, metallic oxide, which are coated with said metals, are used as the material to be plated. For example, 10g Cu powder of 40mu average particle diameter is added into an aqueous tin chloride soln. of 5% Sn concn. contg. 4g Sn powder of several mu average particle diameter, and is reacted at 90 deg.C temp. for 1hr while stirring. The reaction product is separated by filtration, washed with dil. sulfuric acid of 2- 3pH until chlorine ions are removed completely, then it is washed with water and is dried to form 13.98g Sn-plated powder. The filtrate is aqueous tin chloride soln., and it is reutilized for plating reaction. |
