Extraction Characteristics of Niobium(V) and Tantalum(V) on Trioctylmethyl Ammonium Chloride-Impregnated Polyurethane Foam

Abstract

A reagent-impregnated polymer material has been prepared with trioctylmethyl ammonium chloride (TOMAC) and polyurethane foam as a new type of extractant for niobium and tantalum. Niobium(V) and tantalum(V) can be easily concentrated from their hydrofluoric acid solutions with TOMAC-impregnated polyurethane foam. The log D value for tantalum(V) is more than 4 in the HF concentration range from 0.5 to 2 mol·L^?1. The recovery of tantalum(V) from hydrofluoric acid solutions containing a large amount of niobium(V) has been successfully carried out by a batch technique. Extraction characteristics of the present system are similar to solvent extraction rather than to conventional anion-exchangers with respect to the dependence of the value of log D on hydrofluoric acid concentration.