Improvement of calcium fluoride crystallization by means of the reduction of fines formation

This work focuses on fluoride recovery as a solid product CaF2 in order to (i) improve process efficiency by means of the reduction of fines formation with the distributed feeding of calcium along the height of the reactor when high fluoride concentrations have to be treated; and (ii) to correlate the supersaturation effect on the fines formation and the process efficiency for the fluoride recovery as synthetic calcium fluoride. An estimation of two parameters related to the product growth and the fines formation equations was performed in order to predict the process efficiencies in terms of fluoride removal and recovery as a solid product. The process simulation also provided the description of the crystallization process carried out in the tubular reactor contributing to the design and operation purposes for industrial applications of the fluoride control with recovery of solid product recovery as synthetic CaF2 in pellet form available for industrial use.