Study on the Pre-Concentration of Spodumene Using Dense Medium Cyclone

Dense medium cyclone (DMC) separation offers a potential route for the pre-concentration of spodumene ores prior to downstream grinding and flotation. In this study, the effects of dense medium suspension density and feed pressure on spodumene pre-concentration were investigated through actual ore separation tests combined with CFD simulations. Under the optimal conditions of a feed pressure of 150 kPa and a medium density of 2200 kg/m3, the Li2O grade increased from 1.30% in the feed to 5.72% in the concentrate, with a Li2O recovery of 77.23% and a separation efficiency of 60.42%. CFD results showed that the optimal operating conditions produced a relatively stable flow field with lower turbulent kinetic energy. Excessively high medium density or feed pressure increased the probability of fine spodumene particles reporting to the overflow, resulting in lithium losses, whereas insufficient medium density or feed pressure promoted the misplacement of gangue minerals into the concentrate. These results clarify the effects of key operating parameters on spodumene separation in a DMC and provide a basis for optimizing the pre-concentration of hard-rock lithium ores.