| 摘要 |
PROBLEM TO BE SOLVED: To effectively recover noble metal contained from an electrode material as a catalyst without generating subsidiary harmful material.SOLUTION: The electrode material is dipped into an acidic solution by adding an oxidant, such as hydrogen peroxide and ozone, while holding halogen ion concentration into ≥6 mol/L and in such a state, a first process-leaching, in which the liquid temperature of the acidic solution is suitably held to a first temperature zone of 30-65°C, is performed, and successively, a second process-leaching, in which the liquid temperature of the acidic solution is raised and suitably held to a second temperature zone of 80-110°C, is performed. It is desirable that the halogen component in the acidic solution is chlorine ion. |
