An overview of coarse particle beneficiation of lithium ores.

The increasing demand for lithium-ion batteries particularly for electric vehicles underscores the importance of improving the sustainability of lithium mining operations. The depletion of high-grade lithium ore deposits has necessitated the upgrading of medium to low-grade ores for lithium extraction. Spodumene is the most commercially exploited lithium-bearing mineral found in pegmatites due to its high lithium content. Ore sorting can be used for early rejection of up to 60% of gangue minerals prior to preconcentration. Dense media separation is a viable spodumene beneficiation method. However, as case studies have shown, flotation may still be required to process middlings and the undersized fraction, which falls outside the particle size range effective for dense media separation. Magnetic separation can be conducted during or after flotation to remove iron impurities in lithium concentrates. While fine particle flotation has historically achieved high recovery rates, their economic feasibility is increasingly questioned due to intensive comminution requirements. Coarse particle flotation in mechanical flotation cells for instance is inefficient due to turbulence-induced detachment of coarse particles. Coarse particle beneficiation using fluidized bed flotation cells can offer advantages such as reduced grind size and environmental footprint. Despite proven energy savings and recovery efficiencies in other mineral sectors, their application in lithium mining operations remains limited to pilot scale. Also, research in this area is underexplored. This review addresses this gap by evaluating the feasibility, potential benefits and challenges of integrating ore sorting, dense media separation, magnetic separation and fluidized bed flotation with the HydroFloat, NovaCell and Reflux cells into lithium ore beneficiation flowsheets. Key challenges identified include high water consumption and the inadvertent entrainment of fine particles requiring desliming steps. Furthermore, this review acknowledges the challenges in spodumene beneficiation due to the structural similarities among silicate minerals and highlights relevant pretreatment methods to improve selectivity, recovery and grade.