Mechanism of re‐crystallisation in calcium sulphate hemihydrate plasters

作者：K. Schiller · 发表于：Journal of Applied Chemistry · 年份：1962 · DOI：10.1002/jctb.5010120310 · 被引用次数：43 · 研究领域：Calcium Carbonate Crystallization and Inhibition、Crystallization and Solubility Studies、Minerals Flotation and Separation Techniques

Abstract The course of a hydration process is uniquely determined by simultaneous consideration of (a) the balance between the matter dissolving from the original phase and growing on the new phase, (b) the mechanism of mass transport (diffusion), (c) the correlation between the mass deposited on the new particles and its rate of growth and (d) the conservation of mass. An estimate shows that, in the case of neat calcium sulphate plasters, diffusion is quantitatively unimportant as a rate‐determining factor and the corresponding simplifications are introduced. As a result, the hydration can be described in terms of one single parameter which depends on the slurry density, the rate of growth constant for the new phase, the difference in solubilities of the two phases, the shape of the new phase, and the effective number of nuclei for the new phase. Supporting experimental evidence is supplied and discussed.