Models, crystallization process particle characteristics

Several reported chemical systems of gas-liquid precipitation are first reviewed from the viewpoints of both experimental study and industrial application. The characteristic feature of gas-liquid mass transfer in terms of its effects on the crystallization process is then discussed theoretically together with a summary of experimental results. The secondary processes of particle agglomeration and disruption are then modelled and discussed in respect of the effect of reactor fluid dynamics. Finally, different types of gas-liquid contacting reactor and their respective design considerations are overviewed for application to controlled precipitate particle formation. 

These characteristic features are manifested also in the generation-recombination processes of the Frenkel defects in real crystals. However, in contrast to the box model, in a crystal statistical screening of the recombing particles occurs in coordinate space that leads to a complex spatial distribution of vacancies v and interstitial atoms i. This distribution depends on the law whereby the probability of recombination varies with the distance r between complementary particles. Usually one approximates this law by the step-distribution cr(r) = 1 (r ro), er(r) = 0 (r > ro), ro is a recombination radius. 

Figure 10. Model illustrating the changes in crystallite/particle/crystal characteristics during drying/annealing processes.

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