Separation of divalent manganese and cobalt ions from sulphate solutions using sodium salts of D2EHPA, PC 88A and Cyanex 272

The extraction and separation of Mn(II) and Co(II) from sulphate solutions have been carried out using sodium salts of di-(2-ethylhexyl) phosphoric acid (D2EHPA), 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC 88A) and bis-(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) in kerosene. The percentage extraction for the metal ions was increased with increasing equilibrium pH in the case of all the extractants, Manganese was preferentially extracted over cobalt with the extractants and NaD2EHPA was found to be the most suitable extractant for separation, the separation factor being maximum with 0.05 M NaD2EHPA at equilibrium pH 4.45. Manganese and cobalt extractions were carried out at O:A ratio of 9:8 and 1:1, respectively, followed by their strippings at O:A ratio of 2:1 and 4:3 using 0.02 M H2SO4. (C) 2000 Elsevier Science B.V. All rights reserved.