Enrichment of Nb and Ti from carbonatite pyrochlore ore via calcining-slaking followed by gravity separation
Shuhui Zhang, Mingjun Rao, Rendong Xiao, Jinxiang You, LI Guang-hui, Tao Jiang
Abstract
In this work, a novel process consisting of calcining-slaking followed by gravity separation for the enrichment of niobium (Nb) and titanium (Ti) from carbonatite pyrochlore ore was proposed, validated and compared with the current mainstream flotation method. During calcining of the pyrochlore ore, within which the carbonates were transformed into lime. Subsequently, when the calcined ore was slaked, lime was transformed into hydroxide with fine particles which were amenable to gravity separation. After calcining at 900 ℃ for 60 min, slaking at 90 ℃ for 10 min with a liquid–solid ratio of 3:1 (mL/g), approximately 40% of tailings can be removed by gravity separation, the recoveries of Nb and Ti were 94.7% and 91.0%, and the enrichment ratios of Nb and Ti were 1.61 and 1.43, respectively. The new approach exhibits high separation efficiency of carbonate gangue minerals and valuable minerals, satisfactory recoveries of niobium as well as titanium can be achieved.