Investigation of the initial period of sulphate scale formation Part 2. Kinetics of calcium sulphate crystal growth at its crystallization on a heat-exchange surface

Experimental data on calcium sulphate crystal growth (gypsum) from electrolytic solutions on a heated metal surface were considered. It was shown that crystals grew along a heat transfer surface, in parallel to it. The growth kinetics in the direction [100] under investigated experimental conditions were described by a quadratic dependence to supersaturation. The crystal growth in the direction [001] under the same conditions occurred in a mixed mode according to mononuclear growth mechanism by means of two-dimensional nucleus formation on the crystal surfaces. The specific surface energy and activation energy of the crystal growth process were determined.