| 摘要 |
PURPOSE:To recover an aqueous chromic acid soln. of high purity from a spent chromium plating soln. by adding an alkali hydroxide to the plating soln. to remove iron and tervalent Cr as impurities, adding a barium salt to precipitate barium chromate and dissolving the barium chromate in sulfuric acid. CONSTITUTION:An alkali hydroxide is added to a spent chromium plating soln. to precipitate iron and tervalent Cr, which are then removed by filtration. A barium salt is added to the resulting filtrate to precipitate barium chromate. This barium chromate is separated by filtration and sulfuric acid is added to the barium chromate to produce an aqueous chromic acid soln. and barium sulfate. The supernatant liq. is utilized again as a chromium plating soln.
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