CATALYST PRETREATMENT

摘要

Described herein is an improved pretreatment method for preparing powdered catalysts with well controlled particle size distributions that are free of sub 1 micron (1 micrometre) particles comprising dispersion of the powdered catalyst in liquid comprised of either a) a hydrocarbon containing low levels of a surfactant or, b) a surfactant containing polar protic solvent, followed by decantation of the suspended finely divided sub 1 micron (1 micrometre) particles and repeating said sequence until essentially 90% of the sub 1 micron (1 micrometre) particles have been removed.