The crystallization kinetics of potassium chloride in the presence of additives with common ions

Abstract

In this study, the growth and dissolution rates of closely sized KCl crystals that were classified with respect to their separation voltages in an electrostatic separator were investigated in the presence of K2SO4, CH3COOK, NH4Cl and BaCl2 additives, having common cations or anions. Separation voltages were taken as a measure of surface potential. The experiments were carried out in a typical stagnant medium type single crystal measurement system.From experimental results it is observed that thread-like growth behaviors resulting from surface nucleation were dominant and dead zones where there was no growth or dissolution did always exist. For additives having common cation, it was found that the growth in the thread-like structure increases with the increase of surface potential. It was also found that, additives having common anions, initially led to decrease and neutralize the surface potential, then oppositely charged the crystal surface, when the crystal growth/dissolution behavior changes were considered. This study obviously proved that, crystal growth and dissolution behaviors can be controlled by changing the surface potentials of crystals by using additives having common ions.