SECONDARY NUCLEATION OF SODIUM-CHLORATE STUDIED WITH THE AID OF ASYMMETRIC CRYSTALLIZATION

The size-dependent breeding of sodium chlorate crystals can be determi ned by carrying out experiments with seed crystals of optical antipode s of different sizes that undergo absolutely identical experimental co nditions. Small portions of right- and left-handed seed crystals of di fferent sizes were used. The number density distributions of the two o pposite forms led to the total numbers of D- and L-crystals. The nucle ation from different seed sizes under identical experimental condition s was found to be proportional to L-4 in agreement with Clontz et al. [1] and Bennett et al. [2]. A computer program for the modelling of ba tch crystallization was used to calculate the development of the nucle ation process. The data for the supersaturation course and for the dev elopment of the population of the right- and left-handed crystals are in good agreement with the experimental results. Only few generations (one or two) of secondary nucleation are being built during the proces s because of the strong influence of the size of crystals on the nucle ation rate. The formation of two generations of secondary nuclei could be observed during three-hour batch crystallization runs.