A dry
refractory composition having superior insulating value. The dry
refractory composition also may have excellent resistance to molten metals and slags. The composition includes filler lightweight material, which may be 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 mulllite,
cordierite, and
anorthite, and matrix material, which may be 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, carbon, and
calcium fluoride. The composition also may include dense
refractory aggregate, which may be 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, fused magnesia, sintered
spinel, and fused
spinel refractory
grog, a heat activated bonding agent, and a dust suppressant.