The abrasion resistance of a fluidised bed catalyst support

A new full scale manufacturing plant for a fluidised bed catalyst powder, made by spray drying of an aqueous precipitated thixotropic slurry, initially produced particles having poor abrasion resistance. In contrast, the laboratory and pilot plant preparations invariably had high abrasion resistance. Investigation ultimately showed this to be due to the altered structure of the spray-dried particles caused by preceding changes in the colloidal structure of the thixotropic slurry precursors. The changes in the slurry were caused by agitation-agglomeration due to high shear rates in the primary washing stages intended to remove electrolytes. The colloidal structures developed in slurries may need to be considered in other similar processes. They may affect powder properties such as sintering and pelletability as well as abrasion resistance.