Patent ID: 7344988

Claim:
A method of preparing an alumina abrasive slurry comprising the steps of: A) passing a composition comprising AlX 3 through a flame produced from a hydrogen and oxygen gas mixture, wherein the flame has a flame temperature; B) mixing the composition comprising AlX 3 with an inert quenching gas in an amount sufficient to cool the flame temperature to a temperature that is less than 95% of a maximum flame temperature attainable by the AlX 3 and the hydrogen and oxygen gas mixture without the inert quenching gas; and C) admixing water with the resulting fumed alumina particles, which are present as fumed gamma alumina in a yield of at least about 80% by weight, to form a pre-slurry comprising water and between 5% and 50% by weight of the fumed gamma particles; wherein the fumed gamma alumina particles have a pre-milled average particle size D 50 between about 0.06 μm and about 0.2 μm.