The Recovery and Concentration of Spodumene Using Dense Media Separation

In coming years, global lithium production is expected to increase as the result of widespread electric vehicle adoption. To meet the expected increase in demand, lithium must be sourced from both brine and hard-rock deposits. Heavy liquid separation (HLS) and dense media separation (DMS) tests were conducted on the pegmatites from Hidden Lake, NWT, Canada to demonstrate the potential role of this technology in the concentration of spodumene (LiAlSi2O6) from hard-rock sources. A continuously operated DMS circuit test, conducted on +840 µm material, produced a concentrate grading 6.11% Li2O with ~50% lithium recovery. The circuit rejected 50% of the original mass to tailings, with only 8% lithium losses. Sensitivity analysis showed that minor changes (+/−0.05) in the DMS-specific gravity cut point resulted in significant changes to the mass rejected and to the concentrate grade produced; this may limit the feasibility and operability of the downstream grinding and flotation circuits. The results demonstrate the potential for DMS in the concentration of spodumene from the Hidden Lake pegmatites, and by extension, the potential for DMS in the concentration of spodumene from other hard-rock occurrences.

Study on a Sink and Float Test of a Lead-Zinc Ore from Yunnan

The paper analyses problems of a lead-zinc ore from Yunnan with a sink and float test. In the paper, we explored the possibility of pre-discarding about the ore by dense-media process. Dense liquids with the specific gravity of 2.6, 2.7 and 2.8 were used in the test, respectively. -12mm crudes were taken into the test. Finally, it revealed that pre-discarding by dense-media separation can be used in the ore. 2.7 was taken as the best specific gravity of separation. 12~1mm was used as the optimal fraction of pre-discarding by dense-media separation. Pre-discarding rate was 45.53%. The light product with a lead grade of 0.29% and a lead recovery of 4.29% was pre-discarded in which the grade and recovery of zinc were 0.22 and 5.84, respectively.