Liquid-liquid extraction of tin(IV) from hydrochloric acid solutions by di( 2-ethylhexyl) phosphoric acid

Abstract

The distribution of tin(IV) between aqueous hydrochloric acid solutions and solutions of di(2-ethylhexyl) phosphoric acid (DEHPA, HX) in kerosene has been investigated under different conditions. Spectrophotometry, infrared and nuclear magnetic resonance spectral measurements were made of the organic extracts. As a result, it was found that the extraction of tin(IV) at low aqueous acidity is governed by an ion-exchange reaction SnCl 2+ 2 (aq) + (HX) 2(org) ⇌ SnCl 2X 2(org)+2H +(aq), and at higher acidity by a solvating reaction SnCl 4 (aq) + (HX) 2(org) ⇌ SnCl 4 2HX(org).