Process for the recovery of niobium oxide from pyrochlore concentrate

CIM Bulletin, Vol. 78, No. 873, 1985

G. GABRA, Ministere de I'Energie et des Ressources, Centre de Recherches Minerales, Gouvernement du Quebec, Sainte-Foy, Quebec

A process of leaching niobium oxide from pyrochlore concentrate using hydrofluoric acid is described. Variables such as acid concentration, temperature, reaction time, solid/acid ratio, agitation speed and particle size are correlated to the recovery of niobium oxide. The relatively low activation energy (1,86 Kcal/mole) and the dependence of reaction rate on agitation suggest that the process is diffusion controlled. The optimum conditions for extracting niobium oxide from the leach solution, using either methyl isobutyl ketone or tributyl phosphate have been determined.
Mots Clés: Extractive metallurgy, Solvent extraction, Leaching, Niobium, Tantalum, Pyrochlore concentrate.