Selective removal of chromium from sulphuric acid leach liquor of ilmenite ore by solvent extraction with trioctylamine

Abstract

The selective removal of chromium, a trace impurity that degrades the whiteness of titanium(IV) oxide pigments, from sulphuric acid leach liquor of ilmenite, was investigated by solvent extraction with xylene solutions of trioctylamine. Important factors of commercial significance affecting the extraction operation have been examined. More than 99% of the chromium was selectively removed in multiple batch extractions from the leach liquor and titanium losses were minimal (< 1%). The chromium content of extracted solutions was reduced to less than 1 ppm and thermal hydrolysis of these solutions yielded white titanium(IV) oxide pigments that are suitable for use in the coatings pigment industry.


(Received April 11, 2000, revised November 28, 2000)



Bull. Chem. Soc. Ethiop. 2000, 14(2), 115-122

Bulletin of the Chemical Society of Ethiopia.   ISSN: 1011-3924