Extraction of noble metals with macrocyclic compounds III: Extraction with calyxarenes

The third and final part of a review on the extraction of noble metals by macrocyclic compounds, which is devoted to extraction with O-, S-, and N-containing calyxarenes with a generalization of References from 1978 to 2008, is presented. it is noted that no systematic investigations on the extraction of noble metals with calixarenes has been performed until now. most works are qualitative and do not consider the regularities of the influence of the compositions of aqueous and organic phases and the properties of the extractant on the degree of metal extraction. the studied solutions are unlike production ones in regards to composition, and the chemical state of extracted ions in aqueous solutions is not always taken into account. it is emphasized that there is only fragmentary information on reextraction in the literature. the problem of the selectivity of extraction of noble metals with calixarene esters is discussed.