| 摘要 |
<p>PROBLEM TO BE SOLVED: To recover valuable metal with high purity and to easily execute the recycle of a waste soln., to ions to be recovered, by adding ions having the number of value different from that of this one and recovering the metal to be recovered as precipitates. SOLUTION: When a mixed soln. is, for example, composed of three kinds of ions of A+ (Na, Li or the like), B2+ (Fe, Ni, Co or the like) and C3+ (Al or the like), firstly by using a membrane having the permselectivity of cations, A+ and B2+ and C3+ are physically separated. Next, to the mixed soln. of B2+ C3+, D+ (alkali hydroxide such as NaOH, LiOH or the like) is added, by which B2+ is recovered. To the remaining soln. of C3+ and D+, E2+ (Ca, Mg or the like) is added to recover C3+. The remaining soln. of D+ and E2+ is separated by using a permselective membrane, and they are reutilized as a soln. of D+ and a soln. of E2+.</p> |
