Study of extraction systems based on the mixtures of phosphorylated calix[4,6]arenes with dioctyl sulfide for recovery of triaquatrinitrorhodium species from acid nitrate-nitrite solutions

Abstract

A comparison was made for extraction systems based on the mixtures of calix[n]arenes phosphorylated at the upper and lower rims (PCA, n = 4 and 6) with dioctyl sulfide (DOS) for recovery of rhodium in the form of [Rh(H2O)3(NO2)3]0 from acid nitrate-nitrite media. Because of inertness of rhodium compounds, the main attention was devoted to extraction kinetics. The kinetic efficiency of DOS + PCA systems was found to be much higher than that for DOS alone, whereas the components of the mixtures do not extract rhodium. Alkyl(ethyl)calixphosphine oxides are the most promising, they behave as accelerating additives in extractant mixtures. Extraction kinetics of [Rh(H2O)3(NO2)3]0 species was studied and extraction systems were selected to develop method for the recovery of fission rhodium.