Certain embodiments of the present disclosure relate to ceramic materials with high thermal shock resistance and high erosion resistance. In one embodiment, a ceramic material is formed from a composition comprising Al.sub.2O.sub.3, MgO, SiO.sub.2.

A container for heat treatment of a positive-electrode active material for a lithium-ion battery to the present invention is characterized by having a base portion containing 60 to 95 mass % of alumina, and a surface portion containing 20 to 80 mass % of spinel and formed integrally with the base portion. Moreover, a production method of the present invention is characterized by comprising a step of placing an alumina-based powder, a step of placing a spinel-based powder above the alumina-based powder, a step of forming a compact by compressing the powders and a step of firing the compact.

A container for heat treatment of a positive-electrode active material for a lithium-ion battery to the present invention is characterized by having a base portion containing 60 to 95 mass % of alumina, and a surface portion containing 20 to 80 mass % of spinel and formed integrally with the base portion. Moreover, a production method of the present invention is characterized by comprising a step of placing an alumina-based powder, a step of placing a spinel-based powder above the alumina-based powder, a step of forming a compact by compressing the powders and a step of firing the compact.

Particles for a monolithic refractory are made of a spinet porous sintered body which is represented by a chemical formula of MgAl.sub.2O.sub.4, wherein pores having a pore size of 0.01 μm or more and less than 0.8 μm occupy 10 vol % or more and 50 vol % or less with respect to a total volume of pores having a pore size of 10 μm 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 μm occupy 60 vol % or less, particles having a particle size of 45 μm or more and less than 100 μm occupy 20 vol % or more and 60 vol % or less, and particles having a particle size of 100 μm or more and 1000 μm or less occupy 10 vol % or more and 50 vol % or less.

A refractory, coarse ceramic product including at least one granular refractory material, has an open porosity of between 22 and 45 vol.-%, in particular of between 23 and 29 vol.-%, and a grain structure of the refractory material, wherein the medium grain size fraction with grain sizes of between 0.1 and 0.5 mm is 10 to 55 wt.-%, in particular 35 to 50 wt.-%, and wherein the remainder of the grain structure is a finest grain fraction with grain sizes of up to 0.1 mm and/or coarse-grain fraction with grain sizes of more than 0.5 mm.

A refractory, coarse ceramic product including at least one granular refractory material, has an open porosity of between 22 and 45 vol.-%, in particular of between 23 and 29 vol.-%, and a grain structure of the refractory material, wherein the medium grain size fraction with grain sizes of between 0.1 and 0.5 mm is 10 to 55 wt.-%, in particular 35 to 50 wt.-%, and wherein the remainder of the grain structure is a finest grain fraction with grain sizes of up to 0.1 mm and/or coarse-grain fraction with grain sizes of more than 0.5 mm.

Provided is a layered double hydroxide membrane containing a layered double hydroxide represented by the formula: M.sup.2+.sub.1−xM.sup.3+.sub.x(OH).sub.2A.sup.n−.sub.x/n.mH.sub.2O (where M.sup.2+ represents a divalent cation, M.sup.3+ represents a trivalent cation, A.sup.n− represents an n-valent anion, n is an integer of 1 or more, and x is 0.1 to 0.4), the layered double hydroxide membrane having water impermeability. The layered double hydroxide membrane includes a dense layer having water impermeability, and a non-flat surface structure that is rich in voids and/or protrusions and disposed on at least one side of the dense layer. The present invention provides an LDH membrane suitable for use as a solid electrolyte separator for a battery, the LDH membrane including a dense layer having water impermeability, and a specific structure disposed on at least one side of the dense layer and suitable for reducing the interfacial resistance between the LDH membrane and an electrolytic solution.

A method of manufacturing ceramic tape includes a step of directing a tape of partially-sintered ceramic into a furnace. The tape is partially-sintered such that grains of the ceramic are fused to one another yet the tape still includes at least 10% porosity by volume, where the porosity refers to volume of the tape unoccupied by the ceramic. The method further includes steps of conveying the tape through the furnace and further sintering the tape as the tape is conveyed through the furnace. The porosity of the tape decreases during the further sintering step.

A method of manufacturing ceramic tape includes a step of directing a tape of partially-sintered ceramic into a furnace. The tape is partially-sintered such that grains of the ceramic are fused to one another yet the tape still includes at least 10% porosity by volume, where the porosity refers to volume of the tape unoccupied by the ceramic. The method further includes steps of conveying the tape through the furnace and further sintering the tape as the tape is conveyed through the furnace. The porosity of the tape decreases during the further sintering step.

Disclosed is a refractory product for casting of steel, which is capable of forming a dense surface layer which is high in terms of a slag infiltration suppressing ability and strong, in a surface region thereof efficiently or sufficiently or in an optimum state. The refractory product contains 1 mass % or more of free carbon, and 2 mass % to 15 mass % of an aluminum component as metal, with the remainder comprising a refractory material as a main composition, wherein the refractory product has a permeability of 1×10.sup.−16 m.sup.2 to 15×10.sup.−16m.sup.2.