In the present invention, in producing a SiC single crystal in accordance with a solution method, a crucible containing SiC as a main component and having an oxygen content of 100 ppm or less is used as the crucible to be used as a container for a Si—C solution. In another embodiment, a sintered body containing SiC as a main component and having an oxygen content of 100 ppm or less is placed in the crucible to be used as a container for a Si—C solution. The SiC crucible and SiC sintered body are obtained by molding and baking a SiC raw-material powder having an oxygen content of 2000 ppm or less. SiC, which is the main component of these, serves as a source for Si and C and allows Si and C to elute into the Si—C solution by heating.

A method for producing a granular material from sintered magnesia by sintering of pressed articles, in particular pellets, from MgO powder, preferably from caustic MgO powder, and subsequent mechanical comminution of the pressed articles, the sintering being carried out in such a way that the granular material has a grain porosity (total porosity), according to DIN EN 993-1:1195-04 and DIN EN 993-18:1999-01, of from 15 to 38 vol %, preferably 20 to 38 vol %. Also, a batch for producing a coarse ceramic, refractory, shaped or unshaped product containing the porous sintered magnesia, to such a product produced from the batch and to a method for its production, to a lining, in particular a working casing and/or a backing, of a large-volume industrial furnace, the lining, in particular the working casing and/or the backing, having at least one such product, as well as to such an industrial furnace.

Herein discussed is a method of sintering a ceramic comprising (a) providing an electromagnetic radiation (EMR) source; (b) (i) providing a layer of intermixed ceramic particles and absorber particles, wherein the absorber particles have a volume fraction in the intermixed particles in the range of no less than 3%; or (ii) providing a first layer comprising ceramic particles and a second layer comprising absorber particles in contact with at least a portion of the first layer, wherein the second layer is farther from the EMR source than the first layer; (c) heating (i) the layer of intermixed particles or (ii) the first layer using EMR; and (d) controlling the EMR such that at least a portion of the ceramic particles are sintered wherein (i) the layer of intermixed particles becomes impermeable or (ii) the first layer becomes impermeable, wherein the absorber particles have greater EMR absorption than the ceramic particles.

Herein discussed is a method of sintering a ceramic comprising (a) providing an electromagnetic radiation (EMR) source; (b) (i) providing a layer of intermixed ceramic particles and absorber particles, wherein the absorber particles have a volume fraction in the intermixed particles in the range of no less than 3%; or (ii) providing a first layer comprising ceramic particles and a second layer comprising absorber particles in contact with at least a portion of the first layer, wherein the second layer is farther from the EMR source than the first layer; (c) heating (i) the layer of intermixed particles or (ii) the first layer using EMR; and (d) controlling the EMR such that at least a portion of the ceramic particles are sintered wherein (i) the layer of intermixed particles becomes impermeable or (ii) the first layer becomes impermeable, wherein the absorber particles have greater EMR absorption than the ceramic particles.

The invention concerns a fused raw material for the production of a refractory product, a method for the production of the fused raw material and a use of the fused raw material.

A method for producing a granular material from sintered magnesia by sintering of pressed articles, in particular pellets, from MgO powder, preferably from caustic MgO powder, and subsequent mechanical comminution of the pressed articles, the sintering being carried out in such a way that the granular material has a grain porosity (total porosity), according to DIN EN 993-1:1195-04 and DIN EN 993-18:1999-01, of from 15 to 38 vol %, preferably 20 to 38 vol %. Also, a batch for producing a coarse ceramic, refractory, shaped or unshaped product containing the porous sintered magnesia, to such a product produced from the batch and to a method for its production, to a lining, in particular a working casing and/or a backing, of a large-volume industrial furnace, the lining, in particular the working casing and/or the backing, having at least one such product, as well as to such an industrial furnace.

A dielectric porcelain composition having a main component a perovskite compound represented by ABO.sub.3, and the perovskite compound at least contains Ti and a volatile element which forms a solid solution at a B site, and may also contain Zr. The dielectric porcelain composition contains the volatile element in an amount larger than 0 part by mol and less than or equal to 0.2 part by mol with respect to 100 parts by mol of a total of the Ti and the Zr, and has a ratio of an A-site element to the total of the Ti and the Zr of 1.00 or more and 1.04 or less as a molar ratio.

A dielectric porcelain composition having a main component a perovskite compound represented by ABO.sub.3, and the perovskite compound at least contains Ti and a volatile element which forms a solid solution at a B site, and may also contain Zr. The dielectric porcelain composition contains the volatile element in an amount larger than 0 part by mol and less than or equal to 0.2 part by mol with respect to 100 parts by mol of a total of the Ti and the Zr, and has a ratio of an A-site element to the total of the Ti and the Zr of 1.00 or more and 1.04 or less as a molar ratio.

In the present invention, in producing a SiC single crystal in accordance with a solution method, a crucible containing SiC as a main component and having an oxygen content of 100 ppm or less is used as the crucible to be used as a container for a SiC solution. In another embodiment, a sintered body containing SiC as a main component and having an oxygen content of 100 ppm or less is placed in the crucible to be used as a container for a SiC solution. The SiC crucible and SiC sintered body are obtained by molding and baking a SiC raw-material powder having an oxygen content of 2000 ppm or less. SiC, which is the main component of these, serves as a source for Si and C and allows Si and C to elute into the SiC solution by heating.