DETERMINATION OF KINETIC CHARACTERISTICS OF NUCLEATION IN UNSEEDED CRYSTALLIZATION SYSTEMS: COMPARISON OF TWO METHODS

摘要

Kinetic characteristics of primary nucleation of two substances, of potassium chloridernand of carbamic acid-methyl ester derivative, were investigated in batch saltingoutrncrystallization and precipitation experiments, respectively. Two different evaluationrnmethods were used and compared: measuring the induction time, and measuringrnthe average final particle number as a function of the initial supersaturation. Thernvalues of kinetic parameters estimated by means of these independent methods werernfound to be in close agreement. The identified rate expressions predict similar nucleationrnprocesses over the supersaturation range studied. The solid/liquid interfacialrntensions also were calculated for both systems. Based on the solid/liquid interfacialrntension data obtained, the apparent nuclei shape has appeared to be cube for potassiumrnchloride, and plate for carbamic acid-methyl ester derivative.