Abstract
To determine the relationship between crystal growth rate and sodium chloride crystal quality, crystal growth experiments were performed using an agitated continuous crystallizer filled with model mother liquid as the solution, which was a concentrated ionexchange membrane brine. The following results were obtained.
(1) Under all experimental conditions, the crystal form was the same. The crysta form was influenced not by crystal growth rate, but by crystal particle size. Crystals of 0.3 mm or less were cubic, whereas crystals of 0.5 mm or more were spherical. For crystals of more than 0.3 mm and less than 0.5 mm, condensation and wear were observed.
(2) The weight of the solution inclusion decreased with an increase in crystal growth rate.
(3) The potassium and bromide content in crystals increased slightly with an increase in crystal growth rate. The rate of increase of the potassium or bromide ion content was low, under the conditions in which crystals easily condense. The potassium or bromide ion content decreased with an increase in crystal particle size for cubic crystals, however, it increased for spherical crystals.
(4) Assuming that the condensation of cubic crystals whose form is not degraded (i. e., adhesion of fine crystals) contributed to their growth and that condensation of crystals was difficult under the conditions of high wear, it was thought that the adhesion of fine crystals controlled the ion content in the crystals.
