Firing sol-gel alumina particles
AssigneeSaint-Gobain/Norton Industrial Ceramics Corporation
InventorsAjay K. Garg, Arup K. Khaund, Lawrence E. Orne, Mark R. Young
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Abstract
Sol-gel alumina that is dried but unfired can be explosively comminuted by feeding the dried gel into a furnace held at temperatures above those at which vaporizable materials are eliminated from the particles of gel. At suitably elevated temperatures the firing is sufficient to form fully densified alpha alumina particles of a size suitable for direct use as abrasive grits.
Claims21
A process for explosively comminuting a composition comprising a dried but unfired sol-gel alumina said composition having a volatilizable content of at least 5% by weight, which comprises feeding particles of the composition directly into a furnace held at a temperature from about 400.degree. C. to 1600.degree. C. and controlling the residence time in the furnace to produce explosively comminuted alumina particles.
A process for explosively comminuting a composition comprising a dried but unfired seeded sol-gel alumina, said composition comprising from about 20 to about 40% by weight of volatilizable material which comprises feeding the composition into a tubular rotary furnace having a hot zone maintained at a temperature of from about 600.degree. C. to about 1500.degree. C. in which the tube is inclined at an angle of from about 2.degree. to about 20.degree. to the horizontal and rotated at from about 2 to about 20 rpm.
A process for explosively comminuting a dried but unfired unseeded sol-gel alumina comprising from about 20 to about 40% of volatilizable material which comprises feeding the dried. sol-gel into a tubular rotary furnace having a hot zone maintained at a temperature of from about 600.degree. C. to about 1650.degree. C. in which the tube is inclined at an angle of from about 3.degree. to about 20.degree. to the horizontal and rotated at from about 1 to about 20 rpm.
Dependencies are inferred from the claim text.