Thermal insulating firebrick
An object of the invention is to provide, in porous thermal insulating firebricks formed by molding and drying bubble-containing slurry obtained by foaming slurry containing a fire resistant powder and water, a thermal insulating firebrick superior in thermal insulating property in spite of the same composition and porosity. A porous thermal insulating firebrick formed by molding and drying bubble-containing slurry obtained by foaming slurry containing a fire resistant powder with a heat resistant temperature of 1,000° C. or higher and water has the porosity of 60% or more, and 80% or more volume with respect to a total pore volume of the inside of the thermal insulating firebrick consists of pores having a pore size of 200 μm or less.
1. A porous thermal insulating firebrick obtained by a process comprising: molding and drying a bubble-comprising slurry obtained by foaming a slurry comprising a fire resistant powder having a heat resistant temperature of 1,000° C. or higher and water,
wherein
the thermal insulating firebrick has a porosity of 60% or more,
the thermal insulating firebrick comprises pores having a diameter of from about 10 to about 200 μm, and
80% or more volume with respect to a total pore volume inside of the thermal insulating firebrick consists of pores with a pore size of 200 μm or less.
2. The thermal insulating firebrick according to claim 1 , wherein the fire resistant powder comprises a raw material comprising at least one selected from the group consisting of alumina, mullite, andalusite, kyanite, cordierite, spinel, magnesia, and zirconia.
3. The thermal insulating firebrick according to claim 2 , wherein
the fire resistant powder is a high purity alumina powder having a purity of 99% or higher, and
the thermal insulating firebrick has a bulk specific gravity of 1.2 or lower.
4. The thermal insulating firebrick according to claim 2 , wherein the slurry comprises at least one of alumina cement, hydraulic alumina, and calcined gypsum.
5. The thermal insulating firebrick according to claim 3 , wherein the slurry comprises at least one of alumina cement, hydraulic alumina, and calcined gypsum.
6. The thermal insulating firebrick according to claim 1 , wherein the thermal insulating firebrick comprises alumina and comprises pores having a diameter of from about 40 to about 200 μm.
7. The thermal insulating firebrick according to claim 1 , wherein the thermal insulating firebrick comprises mullite and comprises pores having a diameter of from about 10 to about 40 μm.
8. The thermal insulating firebrick according to claim 1 , wherein the thermal insulating firebrick comprises mullite and comprises pores having a diameter of from about 40 to about 200 μm.