Patent ID: 6461584
Filing Date: 2002-10-08
Classification: B82Y,C01F,C01P,C09K

Abstract:
A process for preparing superfine &agr;-alumina powder which comprises the steps of:a) admixing an organic acid surfactant with hydrated alumina precursor in a high speed mixer to disperse the hydrated alumina throughout the surfactant, b) calcining the resulting dispersion in a kiln at a temperature in the range of from 1,000Â° to 1,100Â° C. in an oxygen-depleted atmosphere to produce &agr;-alumina powder, c) cooling the powder to 800Â° C. before exposing it to air to combust remaining carbon, d) comminuting and then centrifuging the cooled powder to obtain nanometer-grade superfine &agr;-alumina powder.