Experimental study on the combined heavy medium-flotation process of a spodumene mine

The lithium ore under investigation assays 1.56% Li₂O, with spodumene identified as the predominant target mineral. The spodumene mineralization occurs primarily in medium to coarse grains, with the majority of particles distributed around the 0.5 mm size fraction. Constraints related to tailings management, including limited available area for tailings storage facilities, necessitate the disposal of a significant portion of process residues. Furthermore, insufficient local power infrastructure restricts the feasibility of large-scale comminution operations, thereby impeding the overall development and utilization of the deposit. In this study, heavy medium separation tests are initially conducted on the spodumene ore. The −0.6 mm fraction derived from HMS and screening operations is subsequently employed as feed material for flotation tests. A systematic flotation investigation is carried out on this fraction. Utilizing a combined “heavy medium separation–flotation” flowsheet, a heavy medium concentrate assaying 5.29% Li₂O with a recovery of 48.03% is obtained. The flotation concentrate graded 6.21% Li₂O at a recovery of 26.90%. The combined concentrate yielded a cumulative grade of 5.59% Li₂O and an overall lithium recovery of 74.93%. This process enables preliminary recovery of coarse-grained spodumene through dense media pre-concentration, generating a final spodumene concentrate product directly. A significant portion of feed material （58.12% by weight） is rejected as coarse tailings, resulting in substantial reductions in crushing and grinding energy consumption. The integration of heavy medium and flotation separation units demonstrates economic viability for lithium extraction, thereby providing critical technical support for the exploitation of lithium resources.