Partic. vol. 52 pp. 28-35 (October 2020)
doi: 10.1016/j.partic.2019.12.002

Enhanced roasting of lepidolite for high defluorination efficiency in a fluidized bed reactor

Jun Li^a, Jing Kong^a, Qingshan Zhu^a,b,*, Hongzhong Li^a

qszhu@ipe.ac.cn

Abstract

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.

Graphical abstract

Keywords

Vacuum fluidized bed; Defluorination roasting; Lepidolite; Lithium