A dielectric composition and a multilayer capacitor including the same are disclosed. The dielectric composition including: a BaTiO.sub.3-based main ingredient; a first auxiliary ingredient including rare earth elements; and a second auxiliary ingredient including at least one of Ba and Ca but essentially including Ba, wherein the rare earth elements include Tb and Dy, and the first auxiliary ingredient and the second auxiliary ingredient satisfy a molar content condition of 0.40<(Tb/T_RE)*(Ba+Ca)<0.93, where T_RE is a total molar content of the rare earth elements in the first auxiliary ingredient.

A method of separating a mixture of used refractory components of different chemistry types obtained from a demolished refractory includes hydrating the mixture of refractory components to destructively hydrate at least some components of the mixture of refractory components, and separating, based on size, the at least some components from other components of the mixture of refractory components.

An abrasive article includes a body having a bond material extending throughout the body and abrasive particles contained in the bond material. The bond material can include aluminum oxide (Al.sub.2O.sub.3) and lithium oxide (Li.sub.2O). In an embodiment, the bond material can include a ratio (Al.sub.2O.sub.3/Li.sub.2O) of a content of aluminum oxide (Al.sub.2O.sub.3) relative to a content of lithium oxide (Li.sub.2O), based on weight percent, of greater than 11.5 and at most 20. In another embodiment, the abrasive article can have a versatility factor of greater than 1.90.

The present invention provides a high alumina fused cast refractory that is easily produced and has low porosity and high corrosion resistance, and a method of producing the same. The high alumina fused cast refractory of the present invention has the following chemical composition: 95.0 mass % to 99.5 mass % Al.sub.2O.sub.3, 0.20 mass % to 1.50 mass % SiO.sub.2, 0.05 mass % to 1.50 mass % B.sub.2O.sub.3, 0.05 mass % to 1.20 mass % MgO and balance. The method of producing the high alumina fused cast refractory of the present invention includes obtaining a mixture by mixing an Al.sub.2O.sub.3 source material, a SiO.sub.2 source material, a B.sub.2O.sub.3 source material and an MgO source material, and fusing the mixture.

A ceramic composite and a method of preparing the same are provided. The method of preparing the ceramic composite includes mixing an aluminum slag and a carbon accelerator to obtain a mixture and reacting the mixture at a temperature equal to or greater than 1600° C. in a nitrogen atmosphere to obtain a ceramic composite. The aluminum slag includes aluminum, oxygen, nitrogen, and magnesium. The weight ratio of the oxygen to the aluminum is 0.6 to 2. The weight ratio of the nitrogen to the aluminum is 0.1 to 1.2. The weight ratio of the magnesium to the aluminum is 0.04 to 0.2. The ceramic composite includes aluminum nitride accounting for at least 90 wt % of the ceramic composite.

A porous refractory cast material contains a closed refractory aggregate fraction having a minimum particle size and a maximum particle size; the ratio of maximum particle size to minimum particle size is 10:1 or less. This closed refractory aggregate fraction comprises all of the porous refractory cast material having a particle diameter greater than 0.1 mm. The porous refractory cast material also contains a binder phase containing refractory selected from calcium aluminate cement, alumina phosphate, hydratable alumina, colloidal silica and combinations thereof. Also disclosed is a metallurgical vessel with an interior lining incorporating the porous refractory cast material.

There is provided at least any of a layered body which has a change in color tone and in which it is unnecessary to select a colorant and the content of the colorant in consideration of a difference in the sintering behavior between layers, a precursor thereof, or a method for producing these. Provided is a layered body which has a structure, in which two or more layers containing stabilizer-containing zirconia and a colorant are layered, and in which types and contents of the colorants contained in the layers are equal to each other, the layered body including at least: a first layer containing a colorant and zirconia which has a stabilizer content of higher than or equal to 3.3 mol %; and a second layer containing a colorant and zirconia which has a stabilizer content different from that of the zirconia contained in the first layer.

A selection method includes: obtaining or providing multilayer ceramic capacitors each having a multilayer structure in which each of a plurality of ceramic dielectric layers and each of a plurality of internal electrode layers are alternately stacked; measuring a ratio of (a current value at 10 V/μm when a direct voltage is applied to a plurality of ceramic dielectric layers at 125 degrees C.)/(a current value at 10 V/μm when a direct voltage is applied to the plurality of the ceramic dielectric layers at 85 degrees C.), with respect to each multilayer ceramic capacitor; determining whether the ratio is in a predetermined range; and selecting a multilayer ceramic capacitor or multilayer ceramic capacitors each having a ratio in the predetermined range as a desired multilayer ceramic capacitor.

An extrudable ceramic precursor mixture and method of use includes: an inorganic ceramic-forming component, a first siloxane prepolymer, a second siloxane prepolymer with a different composition than the first siloxane prepolymer, a catalyst adapted to catalyze polymerization of the first siloxane prepolymer with the second siloxane prepolymer into a siloxane-based polymer, and a thermally curable siloxane-based cross-linking agent adapted to crosslink the siloxane-based polymer. Comprised is a polydimethylsiloxane having a vinyl functional group and a polydimethylsiloxane having a silicon hydride functional group.

The present invention relates to a method for producing a metal nitride by igniting a raw material powder containing a metal powder filled in a reaction vessel under a nitrogen atmosphere and propagating nitriding combustion heat generated by a nitriding reaction of the metal to the whole raw material powder, the method including forming a heat insulating layer made of a material having nitrogen permeability and inert to the nitriding reaction on an upper surface of a layer made of the raw material powder. According to the present invention, it is possible to provide a method for reducing the amount of unreacted metal powder when producing a metal nitride by a combustion synthesis method.