Agglomeration of copper sulfate pentahydrate crystals within well-mixed crystallizers

Abstract Agglomeration of copper sulfate pentahydrate crystals was observed in continuous, semi-batch and batch crystallizers. The supersaturations prevailing at the time of nucleation and subsequent growth were found to be the most important process variables in determining the percentage of resulting particles that were agglomerates. Desupersaturation in batch crystallization was so rapid that few agglomerates were formed. Simple models of the crystal size distribution are ineffective in predicting the percentage agglomerates because of difficulties in separating anomalous crystal growth—which may be caused by size-dependency, growth rate dispersion, or reductions in active growth area—from the phenomenon of agglomeration.