High molecular weight:

Problem:

High molecular weight amines extract the metal ions by a mechanism which is similar to their uptake by solid anion exchangers. In what respects, extraction in high molecular weight amines scores over sorption of metal ions by solid anion exchangers?

Answer:

High molecular weight amines score over solid anion exchanger in the following respects:

i) The extraction process is much faster than the sorption - desorption on ion exchangers.

ii) HMWA - diluent systems offers a wider choice of amines and diluents than that is available with solid anion exchanger. Therefore, several of the separations which are difficult to achieve on solid anion exchangers can be easily accomplished by extraction in an appropriate high molecular weight amine-diluent system.