| 摘要 |
<p>PURPOSE:To recover industrially effective metallic nickel by separating nickel sulfate from a copper electrolytic soln. by crystallization, neutralizing it in the form of an aqueous soln., adding the resulting nickel hydroxide to an aqueous acidic nickel soln., and electrolyzing the soln. at a specified pH. CONSTITUTION:In a copper electrolyzing process part of an electrolytic soln. is fed to a washing process, where it is first freed of copper and treated to separate nickel sulfate, and the residual soln. is recycled to the electrolytic soln. as a concd. soln. of sulfuric acid. The nickel sulfate separated by crystallization is highly refined by washing or recrystallization. The refined nickel sulfate is neutralized in the from of an aqueous soln. with a basic substance such as caustic soda or caustic potash to form nickel hydroxide, which is then settled, filtered, washed, and fed to an electrolyzing process. In the process the nickel hydroxide is added to acidic nickel and electrolyzed at >=0.5pH with a DC power source using lead, platinum-plated titanium or the like as an insoluble anode and a nickel sheet or the like as a cathode to recover metallic nickel.</p> |
