A lab-scale precipitator of alumina trihydroxide (gibbsite) is simulat
ed for three extreme cases of micromixing, these being: the familiar c
ases of Maximum Mixedness and Complete Segregation, and a third case i
n which the fluid is mixed but the solids are segregated. Through this
novel third case, the effect of segregated fluid on the particle size
distribution is distinguished from the effect of segregated solids. I
t is found that these two effects are sometimes in opposition to each
other, and the latter is dominant in a system undergoing aggregation b
ut not nucleation. Few other simulations have considered this. Conclus
ions are drawn on the relevance of micromixing to simulating crystalli
sation, especially when aggregation is significant. (C) 1998 Elsevier
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