Precipitation kinetics of sodium bicarbonate in an industrial bubble column crystallizer

摘要

Sodium bicarbonate is a substance which is produced in the middle stages of the soda ash production process. In this precipitation process, carbon dioxide gas is continuously injected into the bubble column reactor which contains carbonate and bicarbonate solutions. To elucidate the key parameters affecting precipitation kinetics, an experimental study was conducted to understand nucleation and growth in conditions of industrial reactor. The composition of the solution is followed during the crystallization process by titration. Magma density is also monitored and crystal size distribution (CSD) is obtained by sieving. The method of moments was used to determine nucleation and growth rates of crystals. The nucleation and growth rate correlations for sodium bicarbonate precipitation in industrial scale were correlated by empirical power laws as B = 26.685 M-T(0.42) Delta w(1.31) and G = 1.381 x 10(-4) Delta w(1.53). The nucleation and growth rate correlations obtained in this study can be used to simulate the crystallization of sodium bicarbonate plants. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim