Selective dissolution process featuring a classification device for the removal of fines in crystallization: Experiments

Abstract

With the aim of removing fine particles from a suspension obtained by crystallization, a selective dissolution process featuring a hydrocyclone is compared against a well-established partial dissolution process with a dedicated experimental campaign, which complements an earlier theoretical study. For this purpose, 3D printed hydrocyclones, solid- liquid separation devices, are studied in detail and successfully operated under conditions viable at the laboratory scale. A model due to Braun is fitted to the experimental results and validated using a cross validation strategy, thus providing a valuable tool for process simulation. The experimental campaign is designed to comparatively assess the efficacy and efficiency of the two processes under analysis as a function of their respective operating conditions, finally demonstrating the superior performance of the selective dissolution process. In particular, it is shown that while in a standard partial dissolution process 20-40% of the suspended mass has to be dissolved to remove a reasonable amount of fines, the proposed process reaches the same goal by dissolving as little as 3-10%.