Reactive Crystallization Kinetics of Magnesium Hydroxide in the Mg(NO3)2 –NaOH System

Abstract Magnesium hydroxide (Mg(OH) 2 ) is an important chemical raw material and product. Since narrow crystal size distribution of Mg(OH) 2 determines its excellent physical and chemical properties, gaining insight into the reactive crystallization kinetics of Mg(OH) 2 to obtain narrow particle size distribution is essential. The reactive crystallization kinetics of Mg(OH) 2 for the Mg(NO 3 ) 2 ‐NaOH system is systematically investigated during batch crystallization. The effects of supersaturation and temperature on the reactive crystallization kinetics of Mg(OH) 2 are studied. Ion concentration over crystallization time at different temperatures is measured by the conductivity method so that the induction period is well defined. Several kinetic parameters during the nucleation and growth process are determined by using the experimental data of ion concentration over crystallization time at different temperatures. Results show that the induction period decreases with increase of temperature and initial reagent concentration. The specific surface Gibbs energy decreases with the increase of temperature. Crystallization rate increases with increase of temperature and initial reagent concentration, and the nucleation and crystal growth rates can be described as the first order reaction model.