ABSTRACT

Grinstead and his co-workers [1-3] were the first to study extractants composed of an amine, an organic acid, and a diluent, all three components being water immiscible. They tested these extractants for extraction of CaCl2, MgCl2, NaCl, NaBr, NaNO3, and Na2SO4. Their studies were followed by those of other researchers [4-29], who investigated the extraction of many other salts, including chlorides and sulfates of many transition metals. Various names were used for these extractants, including amine salts, mixed extractants, mixed ionic solvents, and binary extractants. In the following, the term acid-base-coupled (ABC) extractants is used.