1987 Volume 51 Issue 8 Pages 743-748
Extraction of Cu, Ni, Co(II) and Co(III) from ammoniacal solution was carried out by using Versatic Acid 10, D2EHPA, PC-88A, LIX64N, SME529 and KELEX100 as extractants, in order to investigate the difference in extraction suppresion by the extractants used.
When the acidic extractants such as Versatic Acid 10, D2EHPA and PC-88A were applied to the extraction from the aqueous solution containing ammonia at high concentration, the strong extraction suppresion was caused by the formation of stable metal-ammine complexes. Metal ions of Cu, Ni and Co were not extracted at all in the pH region of 7-9.5. On the other hand, the extraction suppresion was weak and the extraction of Cu and Co(II) occurred even in the pH range over 10 when chelating extractants such as LIX64N, SME529 and KELEX100 were used for the extraction from the ammoniacal solution. The extent of extraction suppresion is dependent on the sort of metal ions, the ammonia concentration and the sort of extractants. The difference of the extraction suppresion with the sort of extractants seems to be determined by the relation between stability constants of metal ions and extractants and those of metal ions and ammonia.
