The invention discloses castable for gun patching of a
blast furnace lining and a preparation method for the castable. The castable is prepared from raw materials, i.e., 10wt% to 15wt% of
bauxite particles, 40wt% to 50wt% of brown fused
alumina particles, 10wt% to 20wt% of
silicon carbide fine powder, 15wt% to 25wt% of
corundum fine powder, 0.5wt% to 2wt% of
metal silicon powder, 0.5wt% to 2wt% of pelleted
pitch, 2wt% to 7wt% of alpha-Al2O3 micropowder and 0.2wt% to 2wt% of silica micropowder, and silica
sol, of which the weight percentage is 8% to 15% that of the raw materials, wherein the silica
sol serves as a binder. The method comprises the steps of proportionally preparing the raw materials, adding the raw materials in a stirrer, carrying out uniform stirring and mixing, and then, adding the silica
sol as a gun patching
wetting medium and the binder, thereby obtaining the castable for gun patching of the
blast furnace lining. The castable is superior in
slag resistance, high in strength, good in bonding performance and quick in construction and can be integrated with a patched face of the
blast furnace lining through binding; and the preparation method is simple in operation, exposed furnace wall linings can be subjected to gun-patching lining forming under the circumstances that a
stock level of a blast furnace is lowered, and the blast furnace lining is rapidly patched in a large area.