Patent ID: 6458732
Filing Date: 2002-10-01
Classification: C04B

Abstract:
A dry refractory composition, comprising:an insulating refractory material consisting essentially of: a matrix material having a particle size less than 100 mesh in an amount from 5 to 50 volume percent, the matrix material being selected from calcined alumina, fused alumina, sintered magnesia, fused magnesia, silica fume, fused silica, silicon carbide, boron carbide, titanium diboride, zirconium boride, boron nitride, aluminum nitride, silicon nitride, Sialon, titanium oxide, barium sulfate, zircon, a sillimanite group mineral, pyrophyllite, fireclay, calcium fluoride, and mixtures thereof; a dense refractory aggregate having a particle size greater than or equal to 100 mesh in an amount from 0.1 to 80 volume percent, the dense refractory aggregate being selected from calcined fireclay, calcined Chamotte, a sillimanite group mineral, calcined bauxite, pyrophyllite, silica, zircon, baddeleyite, cordierite, silicon carbide, sintered alumina, fused alumina, fused silica, sintered mullite, fused mullite, fused zirconia, sintered zirconia mullite, fused zirconia mullite, sintered magnesia, sintered spinel, fused spinel refractory grog, and mixtures thereof; and a filler lightweight material having a particle size less than or equal to &frac38; inch in an amount from 15 to 85 volume percent, the filler lightweight material being selected from perlite, vermiculite, expanded shale, expanded fireclay, expanded alumina silica hollow spheres, bubble alumina sintered porous alumina, alumina spinel insulating aggregate, calcium alumina insulating aggregate, expanded mullite, cordierite, anorthite, insulating refractory material, and mixtures thereof; the matrix material, dense refractory aggregate, and lightweight filler material being selected so that when the refractory composition in installed in powder form without addition of water or liquid chemical binders in a void adjacent to a heat source, a portion of the composition nearer the heat source forms strong ceramic bonds and a portion of the composition further from the heat source remains in an unbonded fluid form.