| 摘要 |
<p>PURPOSE:To separation-extract high purity Co by treating an aq. soln. contg. Ni, Co, etc. with an org. solvent contg. a specified extracting reagent to separation- extract the Co and by multistage-back-extracting the Co in the solvent with aq. mineral acid solns. of different pH values. CONSTITUTION:Ni and Co are extracted from raw material contg. Ni, Co, etc. with an acid or the like, and the Co is selectively extracted from the Ni and Co-contg. aq. soln. with an org. solvent prepared by diluting an alkylphosphonic acid monoalkyl ester of formula I (where R1 and R2 are same or different 8-10C alkyl) with kerosine or the like. The used solvent is then multistage-treated with an aq. soln. of a mineral acid such as hydrochloric acid or sulfuric acid to back-extract the Co. At this time, the pH of the soln. is adjusted to 1.5-3.5 in the first stage and to 1.0 or less on and after the second stage by supplying the mineral acid. The Co is back-extracted as a high purity aq. soln. in the first stage, and the soln. is electrolyzed to produce metallic Co. The mineral acid solns. contg. impurities such as Zn and Cu on and after the second stage re recycled, and part of the solns. is drawn out of the system to avoid deposition of the impurities.</p> |
