Solubility and Extraction of Metal Ions in the Potassium Bis(Alkylpolyoxyethylene)phosphate (or Alkylbenzyldimethylammonium Chloride)—Potassium (or Ammonium) Thiocyanate—Water Systems at 25°C

Abstract

The solubility in the pseudo-ternary aqueous systems based on potassium bis(alkylpolyoxyethylene)phosphate (oxyphos B) or alkylbenzyldimethylammonium chloride (catamine AB) and potassium or ammonium thiocyanates used as salting-out agents is studied by the isothermal cross-section method. It is found that thiocyanates exhibit a high salting-out capacity with respect to catamine AB and have much lower salting-out properties with respect to oxyphos B. The regularities of extraction of iron(III), copper(II), cobalt(II), zinc and cadmium ions in the potassium thiocyanate-catamine AB-water system in the presence of sulfuric acid are studied. It is demonstrated that these metals can be concentrated groupwise via the anionexchange mechanism when sulfuric acid content in the system is > 0.75 mol/L.