Particle growth kinetics of calcium fluoride in a fluidized bed reactor

Crystallization process in a fluidized bed reactor to remove fluoride from industrial wastewaters has been studied as a suitable alternative to the chemical precipitation in order to decrease the sludge formation as well as to recover fluoride as synthetic calcium fluoride.In the modeling, design and control of a fluidized bed reactor for water treatment it is necessary to study the particle growth kinetics. Removal of fluoride by crystallization process in a fluidized bed reactor using granular calcite as seed material has been carried out in a laboratory-scale fluidized bed reactor in order to study the particle growth kinetics for modeling, design, control and operation purposes.The main variables have been studied, including superficial velocity (SV  , ms-1), particle size of the seed material (L0L0, m) and supersaturation (SS). It has been developed a growth model based on the aggregation and molecular growth mechanisms. The kinetic model and parameters given by the equation G=(2.26×10-10+2.82×10-3L02)SV0.5S fits well the experimental data for the studied range of variables.