CRYSTAL-GROWTH EFFECTIVENESS FACTORS FOR POTASSIUM-SULFATE IN AQUEOUS ORGANIC-SOLVENT SOLUTIONS

Previously reported potassium sulphate crystal growth rate data in two mixed solvent systems viz. aqueous 2-propanol and aqueous propanone solutions within batch and continuous MSMPR agitated vessels respectively are re-analysed in terms of the surface integration effectiveness factor. In both cases, the effectiveness factor generally decreases with increasing concentration of the organic precipitants indicating increased diffusion control. At 2-propanol concentrations x=0. lOw/w and supersaturations a >0.05, however, a local minimum in the effectiveness factor is detected indicating a change in mechanism consistent with an earlier kinetic analysis. These results demonstrate that the concept of effectiveness factors can be conveniently used to quantify the effect of solvents on the growth of potassium sulphate crystals. © 1992, Taylor & Francis Group, LLC. All rights reserved.