Washing Processes for Disperse Particulate Systems – Process Spectrum and Aspects for the Process Choice

Abstract Washing of disperse solid systems is a widely used and complex operation. Since the washing step is mostly integrated into other process operations, it is subject to numerous demands exceeding by far the primary demands, like a good separation result and a low specific wash liquid demand. Because of the phenomenology and limits of different washing processes it is difficult to choose an appropriate washing process. Additionally, the acting transport mechanisms of some washing processes are not yet sufficiently understood. This work gives a broad overview of the existing washing processes, the numerous parameters, and the demands they have to meet. Based on a categorization of washing processes and the classification of these processes according to their macroscopic transport phenomena, an evaluation scheme has been developed which compares and assesses existing washing processes and shows their individual limits. The present work can be used as a rough guideline for the choice of an appropriate washing process.