Abstract
The process of growth of MgCO3·3H2O crystal when Na2CO8 solution was added to MgCl2 solution, was examined by measurement of the concentration of Mg in mother liquid and observation of crystal by microscope.
In this case three stages were recognized under 50°C.(Fig1, Plate I-IV)
The velocity of crystallization at B stage (crystallization of needle crystal from colloidal precipitation) was influenced by temperature (Fig 2), concentration (Fig 3), stirring (Fig 4), etc. The dissolution of the colloidal precipitation was the rate process in this case. The form and size of needlelike crystal were determined chiefly by stiring.
