Extraction of nickel from ammoniacal ammonium carbonate solutions using Acorga M5640 in Iberfluid

Acorga M5640 diluted in Iberfluid was used to extract nickel from ammoniacal/ammonium carbonate solutions. The influence of equilibration time, extractant concentration, equilibrium pH and ammonium carbonate concentration on nickel extraction has been studied. The extent of nickel extraction decreases at equilibrium pH values above 10, whereas the variation of the ammonium carbonate concentration in the range 0-100 g/l only slightly influences the percentage of metal extraction. The loading capacity of a solution of 2.5% v/v Acorga M5640 was determined to be 1.3 g/l Ni at pH 9.5, whereas in the case of 10% v/v extractant the loading increases to 5.2 g/l metal. For a solution which contained 1 g/l nickel and 50 g/l ammonium carbonate (pH 9.5) conditions were established for nickel extraction, selective ammonia stripping and nickel stripping. The percentage of metal extraction and stripping exceeding 99%. (C) 1998 Elsevier Science B.V. All rights reserved.