CRYSTALLIZATION AND DISSOLUTION OF STRONTIUM SULFATE IN AQUEOUS SOLUTION

The kinetics of crystallization and dissolution of strontium sulfate have been studied by following the change in conductivity which occurs when supersaturated or subsaturated solutions are inoculated with seed crystals. The growth of the crystals follows an equation in which the rate of crystallization is proportional to the square of the relative supersaturation in the solution. Under certain experimental conditions, this stage is preceded by an initial growth surge. Evidence, based upon the effect of adsorbates on the crystallization process, is advanced for nucleation on the surface of the crystals during this fast period. The rate of dissolution of strontium sulfate crystals into subsaturated solutions has been found to be proportional to the square of the relative subsaturation after an initial surge of short duration.