| 摘要 |
<p>PROBLEM TO BE SOLVED: To thoroughly recover heavy metals from a solid material and to reclaim the solid material at low cost. SOLUTION: In the method, the solid material 101 and water 102 are mixed and agitated in a mixing tank 11, and the mixture is kept in an alkaline state by adding an alkali 103 in an alkali extractor 12 and the mixture is separated to a solid component 104 and an alkaline aq. soln. 105 at a solid-liq. separator 13. Subsequently, the solid component 104, the water 102 and an acid 106 are mixed to keep an acidic state in an acid extractor 14, and the mixture is separated to a solid component 107 and an acidic aq. soln. 108, and the acidic aq. soln. is electrolyzed in a pre-electrolytic cell 16 to precipitate heavy metals having more noble electric potential than objective heavy metal. After that, only objective heavy metal is precipitated and separated.recovered by electrolyzing the acidic aq. soln. at a main electrolytic cell 17, and the acidic aq. soln. is further electrolyzed at a finishing electrolytic cell 18 to precipitate the heavy metals remaining in the acidic aq. soln. 108.</p> |
