| 摘要 |
<p>PURPOSE:To prevent the sticking of deposited zinc to an aluminum cathode plate by adding a specified amt. of aluminum ion and silicon ion to a soln. of zinc sulfate in sulfuric acid contg. fluoride ion and electrolyzing the soln. CONSTITUTION:A soln. of zinc sulfate in sulfuric acid contg. fluoride ion is electrolyzed to deposit zinc on an aluminum cathode plate, and the zinc is electrolytically refined. At this time, aluminum ion and/or silicon ion are added to the soln. to control any of the molar ratios of F/Al, F/Si and F/(Al+Si). Consequently, the fluoride ion is converted to the complex ion of (Alf6)<3-> or (SiF6)<2-> to weaken the solubility in the aluminum oxide film on the cathode plate surface, metallic aluminum is not exposed on the cathode plate surface, and the releasability of deposited zinc is improved.</p> |
