Secondary Nucleation of Potash Alum

Abstract

This study is aimed at obtaining a correlation between secondary nucleation rates and operating conditions, and their application to industrial crystallization. The secondary nucleation rates of potassium aluminium sulphate 12H₂O (potash alum) are observed in supersaturated solution passed through a multi-crystal bed and correlated against the solution supersaturation and Reynolds number. Mean crystal growth rates of seed crystals, fluidized by the solution, are also studied. Design theories for a classified bed crystallizer are proposed from the secondary nucleation and crystal growth rates, and the operating conditions of an industrial crystallizer are discussed.