Kinetics of crystal growth of $CaCl_2\cdot6H_2O$ from its melt was investigated by the growth velocity measurement inside capillary tubes and the viscosity measurement at various temperatures below the melting point.
The morphology at the crystallization front differed depending on the degrees of supercooling.
The influence of small quantities of soluble impurity on kinetics of crystal growth was also investigated. The results may be summarized as in the following:
1) Below a threshold supercooling the growth velocity was negligible.
2) The dependence of velocity on the supercooling followed the equation $V \cdot \eta$ = $K_1 \cdot\exp(-K_2\cdotT_\circ/\deltaT\cdotT^2)$
3) The crystal-liquid interface showed clearly faceted morphology in the low supercooling.
4) Dissolved NaCl did not change the growth kinetics of $CaCl_2\cdot6HO_2$ but its growth velocity was reduced most likely caused by the difficulties in the $CaCl_2\cdot6H_2O$ molecule transport which resulted from the accumulation of the impurities before the crystallization front.
