Lithium Ore Beneficiation: Sustainable Approaches for Efficient Recovery of Lithium from a Low-Grade Spodumene Ore
摘要
Beneficiating the low-grade lithium ores to remove the gangue minerals and enhancing their grade is an attractive proposition today. The beneficiation of a low-grade spodumene ore from Eastern Kazakhstan is investigated by dense media separation (DMS) and froth flotation to obtain a concentrated lithium product. DMS processed the −1000/+850 µm and −850/+500 µm size fractions, while fine particle of −74/+38 µm of composite samples was carried out by froth flotation. The lithium content of the ore varies between 0.3 and 0.5% Li2O. In the 1000/+500 µm size fraction of DMS testwork, the highest lithium grade of 6.7% was achieved with a recovery rate of about 35% at a separation specific gravity of 3.0, while 90% of the lithium oxide was recovered in 8% of the mass, with a grade of 5.1% Li2O at a separation specific gravity of 2.8. Most of the gangue (over 90%) was effectively removed at a specific gravity of 2.7 for both coarse size fractions. A maximum lithium recovery of approximately 53% with a highest lithium grade of 1.2% was obtained under reverse flotation condition of 1000 g/t NaOL/DAA, mixture ratio of 1:5, pH 10, and dextrin concentration of 4000 g/t. The zeta potential and XPS measurements revealed that the mixed NaOL/DAA system exhibited limited interaction with the spodumene surface, primarily through weak chemisorption and electrostatic adsorption, which led to a reduction in the thickness of the DAA multilayer.
Graphical Abstract