Synergistic Solvent Extraction of Nickel and Cobalt: A Review of Recent Developments

Synergistic solvent extraction of nickel and cobalt has been an important research subject since the 1960s. In recent years, several synergistic systems have been further developed for possible industrial application, including carboxylic acids/pyridinecarboxylates for the separation of nickel and calcium; carboxylic acids/alpha-hydroxyoxime systems for the separation of cobalt from manganese, magnesium, and calcium, and carboxylic acid/alpha-hydroxyoxime/organophosphate systems for the separation of nickel and cobalt from manganese, magnesium, and calcium. The separation of nickel and cobalt from iron and aluminum using synergistic systems has also been explored. Industrial application of synergistic solvent extraction systems is expected in the near future.