Abstract: Particles for a monolithic refractory are made of a spinet porous sintered body which is represented by a chemical formula of MgAl2O4, wherein pores having a pore size of 0.01 ?m or more and less than 0.8 ?m occupy 10 vol % or more and 50 vol % or less with respect to a total volume of pores having a pore size of 10 ?m or less in the particles, and the particles for a monolithic refractory have grain size distribution in which particles having a particle size of less than 45 ?m occupy 60 vol % or less, particles having a particle size of 45 ?m or more and less than 100 ?m occupy 20 vol % or more and 60 vol % or less, and particles having a particle size of 100 ?m or more and 1000 ?m or less occupy 10 vol % or more and 50 vol % or less.

Abstract: A heat insulating material includes a porous sintered body formed of MgAl2O4 and having a porosity of 60% or more and less than 73%. In the heat insulating material, pores having a pore diameter of 0.8 ?m or more and less than 10 ?m occupy 30 vol % or more and less than 90 vol % of a total pore volume, pores having a pore diameter of 0.01 ?m or more and less than 0.8 ?m occupy 10 vol % or more and less than 60 vol % of the total pore volume, the thermal conductivity at 20° C. or higher and 1500° C. or lower is 0.45 W/(m·K) or less, and the compressive strength is 2 MPa or more.

Abstract: A heat insulator including a porous sintered body having a porosity of 70 vol % or more, pores having a pore size of more than 1000 ?m in a proportion of 10 vol % or less of all pores and pores having a pore size of 0.8 ?m or more and less than 10 ?m occupy 50 vol % or more and 80 vol % or less of pores having a pore size of 1000 ?m or less, while pores having a pore size of 0.01 ?m or more and less than 0.8 ?occupy 10 vol % or more and 30 vol % or less pores having a pore size of 1000 ?m or less. The porous sintered body is formed from MgAl2O4 raw material and includes a fibrous layer formed from inorganic material fibers, the heat conductivity of the heat insulator at 1000° C. or more and 1500° C. or less being 0.40 W/m·K) or less.

Abstract: One aspect of the heat insulator of the present invention includes a porous sintered body having a porosity of 70 vol % or more and less than 91 vol %, and pores having a pore size of 0.8 ?m or more and less than 10 ?m occupy 10 vol % or more and 70 vol % or less of the total pore volume, while pores having a pore size of 0.01 ?m or more and less than 0.8 ?m occupy 5 vol % or more and 30 vol % or less of the total pore volume. The porous sintered body is formed from an MgAl2O4 (spinel) raw material and fibers formed of an inorganic material, the heat conductivity of the heat insulator at 1000° C. or more and 1500° C. or less is 0.40 W/(m·K) or less, and the weight ratio of Si relative to Mg in the porous sintered body is 0.15 or less.

Abstract: Particles for a monolithic refractory are made of a spinet porous sintered body which is represented by a chemical formula of MgAl2O4, wherein pores having a pore size of 0.01 ?m or more and less than 0.8 ?m occupy 10 vol % or more and 50 vol % or less with respect to a total volume of pores having a pore size of 10 ?m or less in the particles, and the particles for a monolithic refractory have grain size distribution in which particles having a particle size of less than 45 ?m occupy 60 vol % or less, particles having a particle size of 45 ?m or more and less than 100 ?m occupy 20 vol % or more and 60 vol % or less, and particles having a particle size of 100 ?m or more and 1000 ?m or less occupy 10 vol % or more and 50 vol % or less.

Abstract: One aspect of the heat insulator of the present invention includes a porous sintered body having a porosity of 70 vol % or more and less than 91 vol %, and pores having a pore size of 0.8 ?m or more and less than 10 ?m occupy 10 vol % or more and 70 vol % or less of the total pore volume, while pores having a pore size of 0.01 ?m or more and less than 0.8 ?m occupy 5 vol % or more and 30 vol % or less of the total pore volume. The porous sintered body is formed from an MgAl2O4 (spinel) raw material and fibers formed of an inorganic material, the heat conductivity of the heat insulator at 1000° C. or more and 1500° C. or less is 0.40 W/(m·K) or less, and the weight ratio of Si relative to Mg in the porous sintered body is 0.15 or less.

Abstract: A heat insulating material includes a porous sintered body formed of MgAl2O4 and having a porosity of 60% or more and less than 73%. In the heat insulating material, pores having a pore diameter of 0.8 ?m or more and less than 10 ?m occupy 30 vol % or more and less than 90 vol % of a total pore volume, pores having a pore diameter of 0.01 ?m or more and less than 0.8 ?m occupy 10 vol % or more and less than 60 vol % of the total pore volume, the thermal conductivity at 20° C. or higher and 1500° C. or lower is 0.45 W/(m·K) or less, and the compressive strength is 2 MPa or more.

Abstract: A heat-insulating material is provided in which thermal conductivity is controlled not to increase and good insulation properties are held even in a high temperature range. The heat-insulating material is formed of a spinel porous sintered body having a porosity of 65 to 90 vol. % and represented by a chemical formula XAl2O4 (X=Zn, Fe, Mg, Ni, or Mn) which is arranged such that large pores having a diameter of greater than 1000 ?m occupy 25 vol. % or less of the total pore volume, fine pores having a diameter of 0.45 ?m or less occupy 5 to 40 vol. % of the volume of the pores having a diameter of 1000 ?m or less, at least one pore-diameter distribution peak is within a range of 0.14 to 10 ?m, and is formed of sintered particles having a calculated average particle diameter of 0.04 to 1 ?m.

Abstract: A heat-insulating material is provided in which thermal conductivity is controlled not to increase and good insulation properties are held even in a high temperature range. The heat-insulating material is formed of a spinel porous sintered body having a porosity of 65 to 90 vol. % and represented by a chemical formula XAl2O4 (X?Zn, Fe, Mg, Ni, or Mn) which is arranged such that large pores having a diameter of greater than 1000 ?m occupy 25 vol. % or less of the total pore volume, fine pores having a diameter of 0.45 ?m or less occupy 5 to 40 vol. % of the volume of the pores having a diameter of 1000 ?m or less, at least one pore-diameter distribution peak is within a range of 0.14 to 10 ?m, and is formed of sintered particles having a calculated average particle diameter of 0.04 to 1 ?m.