Aliphatic Non-Chelating Aldoximes as the Effective Extractants for Recovery and Separation of Nickel and Cobalt from Halide and Thiocyanate Solutions

• Published in: Mineral processing and extractive metallurgy review 1995-12, Vol.15 (1-4), p.163-163
• Main Authors: BEZRUKOVA, N.P., PASHKOV, G.L, FLEYTLICH, I.U.
• Format: Article
• Language: English
• ISSN: 0882-7508; 1547-7401
• DOI: 10.1080/08827509508914194

Nickel recovery from solutions containing nickel and cobalt is a problem because the cobalt oxidation in the organic phase and the slow rate of nickel extraction, or small value of separation coefficient (β Ni/Co ) are characteristic of many extraction systems suggested for this purpose. The extraction systems with aliphatic non-chelating aldoximes do not have the above-mentioned shortcomings. The extraction of metal halides from acid solutions by aliphatic aldoximes occurs by coordination. Cobalt in extracts does not oxidize during a day or more. The extraction and stripping equilibriums are reached in 2-5 min. During extraction, Ni and Co do not form mixed extraction complexes. β Ni/Co increases with halide-ions concentration rising in aquoeus phase and is approximately equal to 100 at their concentration > 3 M/l. From chloride to bromide solutions the distribution coefficients of Ni and Co (D Ni , D Co ) decrease, but β Ni/Co does not decrease. In extraction from thiocyanate solutions D Ni , D Co and β Ni/Co reach the values comparable with the same in extraction from chloride solutions, but the process of metal extraction is accompanied by co-extraction of HSCN. The dependence of Ni recovery on out-salting cation has been investigated. Ni recovery has been shown to increase in the order: Na +