Obtaining Monodisperse Melamine Phosphate Grains by a Continuous Reaction Crystallization Process

Abstract

A continuous MSMPR (mixed-suspension mixed-product removal) crystallizer was used in the process of obtaining melamine phosphate in a precipitation reaction. The effects of the mean residence time of the suspension in the crystallizer and of the concentration of the melamine suspension in water on the efficiency of the process and the quality of the product obtained were studied. Kinetic parameters of the reaction crystallization process under study were estimated. The grain size distribution of the crystals and the specific surface area of the grains were determined. Morphology was defined by means of a shape factor and coefficients of inhomogeneity and variation. Well-formed, homogeneous crystals of similar specific surface areas and practically identical small pore volumes were obtained. This work shows that, within the studied range of solid-phase concentrations and mean residence times, it is possible to obtain a product of monodisperse grains and predicted grain size by controlling the concentration...