ACORGA ZNX50 - A NEW SELECTIVE REAGENT FOR THE SOLVENT-EXTRACTION OF ZINC FROM CHLORIDE LEACH SOLUTIONS

The new reagent ACORGA ZNX50 is a formulation of a novel class of reagent developed by ICI specifically for the solvent extraction of zinc from aqueous chloride solutions. The reagent shows remarkably high selectivity for zinc over iron and various other metals including lead, cadmium and antimony. Such reagents are of potential application in new systems, such as hydrometallurgical processes for the recovery of metals from complex sulphide ores based on chloride leaching, solvent extraction, and direct electrowinning from chloride solution. The reagents are also applicable to the recovery of zinc from chloride-containing effluent streams and solutions produced by the chloride leaching of zinc-bearing wastes. ACORGA ZNX50 gives efficient extraction of zinc at ambient temperature from solutions approximately 4-8 molar in chloride ion. The loaded organic phase is readily stripped at 60-65-degrees-C using either water, dilute brine, or spent zinc chloride electrolyte. Test work and trials carried out in laboratory-scale mixer-settlers have confirmed the hydrometallurgical properties, including extraction, stripping, selectivity, good phase separation and long-term stability of the reagent.