Enhanced roasting of lepidolite for high defluorination efficiency in a fluidized bed reactor
Jun Lia, Jing Konga, Qingshan Zhua,b,*, Hongzhong Lia
Defluorination roasting of lepidolite ore in a fluidized bed reactor has been proposed for improving the extraction efficiency of lithium. In this paper, a vacuum was introduced to the fluidized bed reactor, which significantly improved the defluorination efficiency of lepidolite particles. This improvement could be attributed to an increase in the H2O/HF ratio. The highest defluorination rate for the lepidolite particles was obtained in the fluidized bed reactor under vacuum. The rate in the vacuum reactor was 1.5–2 times that in a fixed bed reactor or conventional fluidized bed reactor. The defluorination efficiency of the lepidolite particles also improved and the consumption of steam was greatly reduced by addition of coal char. This enhancement was mainly attributed to changes in the structures of the reduced lepidolite particles. This defluorination roasting method for high lithium extraction with low water steam consumption is a promising method for lithium ore treatment.
Vacuum fluidized bed; Defluorination roasting; Lepidolite; Lithium