| 摘要 |
<p>PURPOSE:To heighten noble metal recovery efficiency by recovering catalytic components separately from a metal support after taking off a wash coat layer from the metal support by heating the metal catalyst in an aqueous nitric acid solution. CONSTITUTION:A metal catalyst containing at least one kind of noble metals selected from a group of platinum, palladium, and rhodium as a catalytic component and coated with a wash coat layer comprised of mainly alumina and ceria is heated in an aqueous nitric acid solution or an aqueous nitric acid solution containing an aqueous hydrogen peroxide solution so as to take off the wash coat layer from the metal support. Then, noble metals are separated and recovered from the metal support. Optionally, a method for recovery of the noble metals by dissolving only noble metals using aqua regia or a mixed solution of hydrochloric acid and hydrogen peroxide after the wash coat layer is taken off followed by precipitating and recovering the noble metals is adopted.</p> |
