Industrial Crystallization Theory and Control of Product Crystal Size in Salt Manufactures

Abstract

Industrial crystallization has some specialities different from diffusion operation in chemical engineering field and ideal crystal growth theory, and these specialities are very important to understand crystallization in a crystallizer. Design theories of crystallizer whose capacity is expressed by production rate and product crystal size, are proposed from two different concepts (ideal behaviors of crystal and solution in a crystallizer, and final product crystal estimated from average nucleation rate, average growth rate, average suspension density), using industrial crystallization theories. These theories are satisfactorily applied for design of industrial continuous crystallizers from laboratory tests' data. Some discussions on data of industrial and laboratory tests of sodium chloride have been done by these design theories, and correlations between product crystal size and production rate in the same continuous crystallizer are studied. newconcept for production of a desired crystal size which is obtained by adjustment of suspension density in the continuous crystallizer, production and nucleation rate, is proposed.