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Feststoffbildung durch Kristallisation und Fällung
Author(s) -
Gösele Walter,
EgelHess Wolfgang,
Wintermantel Klaus,
Faulhaber Friedrich Richard,
Mersmann Alfons
Publication year - 1990
Publication title -
chemie ingenieur technik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.365
H-Index - 36
eISSN - 1522-2640
pISSN - 0009-286X
DOI - 10.1002/cite.330620706
Subject(s) - supersaturation , crystallization , solubility , nucleation , precipitation , crystal growth , metastability , chemistry , solubility equilibrium , crystal (programming language) , crystal habit , amorphous solid , chemical engineering , crystallography , organic chemistry , physics , meteorology , computer science , programming language , engineering
Formation of solids by crystallization and precipitation. Formation of solids from solutions can take place by crystallization or precipitation. The principal factor is the relationship between solubility and supersaturation. In crystallization, the solubility of the crystallising substance is so high that the formation of solids occurs largely in the metastable zone in the immediate vicinity of the solubility limits. Crystal growth and nucleation are functions of supersaturation. If a high supersaturation is required at low substance‐specific growth rates for an adequate crystal growth, high nucleation rates and hence small crystals will result. On this basis, the authors present information for the specific design of crystallization processes. In contrast, the solubility of the precipitated product must be very low for precipitation. Direct crystal formation is possible only for substance systems of high solubility. As a rule, however, the precipitated substance is so insoluble that solids are formed via amorphous intermediates. The results of a large number of experiments show the influence of various parameters of the precipitation process on the filtrability of the precipitated product.