Patent ID: 8834833
Filing Date: 2014-09-16
Classification: C01F,C01P,Y10T

Abstract:
1. A process for process for preparing an aluminium oxide powder which is present in the form of aggregated primary particles and comprises at least 85% by weight of alpha-aluminium oxide, comprising: a) press granulating a pyrogenic aluminium oxide powder which is present in the form of aggregated primary particles into flakes, wherein the pyrogenic aluminium oxide powder is selected from the group consisting of gamma-aluminium oxide, theta-aluminium oxide, delta-aluminium oxide, X-ray amorphous aluminium oxide and mixtures thereof; b) crushing the flakes to produce fragments, wherein the fragments have an average particle diameter of 300 to 800 μm and a tamped density of 300 to 800 g/l; and c) heat treating the fragments at 1300 to 1500° C. and subsequently milling.