Crystallization kinetics of calcium lactate in a mixed-suspension-mixed-product removal crystallizer

Continuous crystallization of calcium lactate pentahydrate was investigated in a mixed-suspension-mixed-product removal crystallizer. Wide ranges of t he mean residence time, relative supersaturation, and magma density were co vered (40-215 min, 0.01-1.12, and 2-65 kg/m(3), respectively). Crystal grow th was found to be dependent on crystal size. The Abegg, Stevens, and Larso n model and the Mydlarz and Jones model were tested for the determination o f the kinetics parameters from experimental results. Zero-size and larger s ize crystal growth rate values were found to be on the order of 10(-13) and 10(-8) m/s, respectively. A first-order growth kinetics resulted for both large and small crystals. Nucleation rate values were very high (approximat e to 10(13)-10(15) no./m(3).S). Nucleation kinetics could not be described by a unique power law equation because two different nucleation mechanisms appeared to control crystallization at low and high residence times, respec tively.