Ion Flotation and Solvent Extraction of Ferric Thiocyanate Complexes

Abstract

The influence of thiocyanate and accompanying mineral acids concentration on the effectiveness of Fe(III) ion flotation, Fe(III) precipitation in cetyl-trimethylammonium ferric-thiocyanate form (as sublate), and Fe(III) extraction using ethyl acetate was studied. The effectiveness of these processes improves with the extent of Fe(III) complexation by thiocyanates. In the presence of acids, flotation and precipitation are increased as follows: HC1O₄ < HC1 < HNO₃ < H₂SO₄. The position of H₃PO₄ in this series changes with changing thiocyanate concentration. Extraction effectiveness is increased in the series: H₃PO₄ < H₂SO₄ < HNO₃, HC1O₄ HCl. The following points are discussed: (a) the influence of acid anions competing with thiocyanate anions in Fe(HI) complexation; (b) the influence of the competition between acid anions and complex ferric-thiocyanate anions in sublate formation; (c) the influence of hydrogen ion concentration increase in thiocyanate medium on the results of Fe(III) flotation, precipitation, and extraction; and (d) the influence of anion affinity for a collector on the solution surface properties and on Fe(III) flotation.