Br. Reddy et Pvrb. Sarma, Transfer of nickel from sodium sulphate solutions to the spent electrolytethrough solvent extraction and stripping, HYDROMETALL, 60(2), 2001, pp. 123-128
Studies on the separation of nickel from concentrated solutions containing
sodium sulphate were carried out with di(2-ethylhexyl) phosphoric acid dilu
ted with kerosene (mostly aliphatic). Increase in extractant concentration,
extent of neutralisation and organic to aqueous phase ratio increase the e
xtraction of nickel. The plot of log D vs. log [extractant] is linear with
a slope of 2.3, indicating that the extracted species is probably NiA(2). E
mploying 0.4 M D2EHPA, nickel was extracted to the extent of 99.6% in three
counter-current stages at an aqueous to organic phase ratio of 1:4. Nickel
was stripped using the spent electrolyte from the loaded organic phase in
three counter-current stages at an aqueous to organic phase ratio of 2.2:1
to the extent of 99.8%. Temperature in the range of 30-60 degreesC has marg
inal effect on the extent of nickel stripping. The pregnant electrolyte wit
h a pH of 4.2 and enriched by about 3.9 kg/m(3) of nickel is suitable for e
lectrowinning to produce nickel cathode. (C) 2001 Elsevier Science B.V. All
rights reserved.