Process development for the recovery of high-grade lanthanum by solvent extraction

• Published in: Hydrometallurgy Vol. 73; no. 3; pp. 237 - 244
• Main Authors: Morais, C.A., Ciminelli, V.S.T.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-06-2004; Elsevier
• Subjects: Applied sciences; Exact sciences and technology; Hydrometallurgy; Lanthanum; Lanthanum extraction; Lanthanum recovery; Metals. Metallurgy; Production of metals; Production of non ferrous metals. Process materials; Lanthanum extraction; Lanthanum recovery; Lanthanum; Hydrochloric acid; Recovery metals; Chlorides; DEHPA; Reagents; Process development units; Experimental study; Solvent extraction; Hydrometallurgy; Lanthanum oxide
• ISSN: 0304-386X; 1879-1158
• DOI: 10.1016/j.hydromet.2003.10.008

The development of a solvent extraction process for the recovery of high-grade lanthanum oxide from a light rare earth (RE) (La, Pr, Nd) chloride solution is described. In a preliminary stage, process parameters and experimental conditions were explored in bench-scale experiments. The effect of variables such as nature and concentration of the extractants (di-2-ethylhexylphosphoric acid [DEHPA] and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester [HEH(EHP)]), contact time, acidity and rare earth concentration in the extraction stage as well as the effect of the hydrochloric acid concentration in the stripping stage were investigated. The continuous counter-current experiments were carried out in a mini-battery unit of mixer-settlers. The final set-up was comprised of 22 stages: 8 for extraction, 8 for scrubbing and 6 for stripping. A high-grade oxide (>99.9% La
2O
3) was obtained with a yield superior to 99.9%.