| 摘要 |
The invention relates to a method for separating the impurities zinc, iron, calcium, copper and/or manganese from aqueous solutions that contain cobalt and/or nickel. An aqueous solution (1) containing metallic salts is brought into a mixing contact with an extraction solution (2), which is pre-loaded with cobalt and/or nickel ions, whereby the cobalt and/or nickel in the extraction solution are replaced with the impurity metals, and the aqueous solution is cleaned from impurities after this phase. This purified aqueous solution, raffinate (3), can be used to pre-charge the extraction solution with cobalt and/or nickel ions, so that a minor part (5) of the raffinate is contacted with a pre-neutralized extraction solution (6), whereby the cobalt and/or nickel replace the alkali metal, alkali earth metal or ammonium ion that is used in the pre-neutralization. After this pre-charging stage, the aqueous solution that contains said alkali metal, alkali earth metal and/or ammonium ion, but no cobalt and/or nickel, is con-veyed as reject (7) out of the process. After the extraction stage, the extraction solution (8) can be washed at a separate washing stage with washing water (9) that contains impurity metal chlorides. In that case, the cobalt and/or nickel ions remaining in the extraction solution are replaced with the impurity ions and they transfer to the chloride-containing aqueous solution. This washing water (11) can be conveyed to the pre-charging stage mentioned above, whereby the chloride ions that come along are removed to the reject. After the washing stage, the impurities can be back-extracted into the aqueous solution by the aqueous solution (13) of hydrochloric acid. |
