Journal of
Chemical Engineering and Materials Science

  • Abbreviation: J. Chem. Eng. Mater. Sci.
  • Language: English
  • ISSN: 2141-6605
  • DOI: 10.5897/JCEMS
  • Start Year: 2010
  • Published Articles: 92

Full Length Research Paper

Purification of cobalt solutions in several solvent extraction steps: Using MEXTRAL and D2EHPA as extractants

Mulaja Tshakatumba Constantin
  • Mulaja Tshakatumba Constantin
  • Metallography and Materials Laboratory, Metallurgy and Materials Science Department, Polytechnics Faculty, University of Lubumbashi, Democratic Republic of the Congo.
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Tshipeshi Makina Héritier
  • Tshipeshi Makina Héritier
  • Metallography and Materials Laboratory, Metallurgy and Materials Science Department, Polytechnics Faculty, University of Lubumbashi, Democratic Republic of the Congo.
  • Google Scholar
Ngoy Moïse Raphael Moramess
  • Ngoy Moïse Raphael Moramess
  • Metallography and Materials Laboratory, Metallurgy and Materials Science Department, Polytechnics Faculty, University of Lubumbashi, Democratic Republic of the Congo.
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Mwema Mutamba Edouard
  • Mwema Mutamba Edouard
  • Metallography and Materials Laboratory, Metallurgy and Materials Science Department, Polytechnics Faculty, University of Lubumbashi, Democratic Republic of the Congo.
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  •  Received: 17 January 2021
  •  Published: 31 January 2021

Abstract

A sulphate solution of cobalt (18.93 g/L Co2+) containing major impurities such as copper (1.35 g/L Cu2+), iron (0.28 g/L Fetot), zinc (0.70 g/L Zn2+) and manganese (4.83 g/L Mn2+) was purified through the solvent extraction method using two extractants; MEXTRAL and D2EHPA for the removal of copper and for the removal in two stages of a zinc-iron-manganese complex respectively. The effects of the solution’s pH, O/A ratio, extraction time and stirring intensity were investigated. The purification extent was enhanced by optimizing these four parameters through Taguchi’s L16 (4^4) experimental. The final solution obtained through sequential extractions showed a reduction in Cu, Fe, Zn and Mn content of 98.7, 97.5, 98.2, and 80.5% respectively. This study showcased the possibility of obtaining high purity cobalt as a precursor for Lithium ion battery applications, representing 49% of its current global use. The coextraction value of cobalt was estimated at 6.2%.

Key words: Purification, MEXTRAL 984N, D2EHPA, cobalt, SX.