A composition for applying to a honeycomb body includes a refractory filler, an organic binder, an inorganic binder, and a liquid vehicle, wherein the refractory filler, the particle size distribution of the refractory filler, the organic binder, and the inorganic binder are selected such that, when the composition is applied to plug a plurality of channels of the honeycomb body, the plug depth variability is reduced.

A self-bonding refractory powder product for use in making a slurry for investment casting molds comprising a coarse refractory powder; a Nano-sized powder; and an organic polymer powder, wherein it does not require aqueous colloidal silica to produce slurries used to build investment casting molds. The Nano-sized powder comprises fumed alumina, boehmite, fumed silica, or fumed titanium oxide or combinations thereof. The coarse refractory powder comprises milled zircon, tabular alumina or fused alumina, fused silica, alumino-silicate, zirconia, and yttria or combinations thereof. The organic polymer powder comprises a cellulose-based material.

Disclosed is a hydraulically and chemically bonding refractory cement, which includes a caustic magnesia component having a BET specific surface area of at least 0.5 m.sup.2/g, and a carboxylic acid component, wherein the carboxylic acid component consists of at least one carboxylic acid that is only slightly water soluble and/or has a low dissolution rate in aqueous solutions, and which carboxylic acid component is capable of generating at least one soluble magnesium salt upon contact of the cement with water. Also disclosed is a corresponding refractory material containing the magnesia cement and to uses thereof for the manufacture of products useful in various industries.

In a method for obtaining a compacted material, a) a set of particles of raw materials is mixed with 1-50% by weight of a hydraulic binder to form a dry composition, the percentage being relative to the total weight of the dry composition, the particle size distribution of the raw material particles being characterised by a first reference diameter 50 millimetres and a second reference diameter 0.08 micrometres, b) the dry composition is mixed with 1-35% by weight of water to form a mixed composition, the percentage relative to the total weight of the dry composition, c) the mixed composition is vibrated 0.3 millimetres at 20-80 Hertz, while a compressive stress is applied, the value of the applied compressive stress being at least 2 MegaPascal. Also disclosed is a method for obtaining a multilayer compacted material and to the materials obtained according to the methods.

The present invention is a granular material that can be well recoated regardless of the type of the granular material, and enables a refractory aggregate in an unprinted portion to be used without any regeneration process, in the manufacture of a three-dimensional laminated and shaped mold. This granular material is a granular material for use in three-dimensional laminated mold shaping, and obtained by adding a material that causes a hydration reaction having a moisture absorbing function and generates a catalytic effect to a coating material mixed with or coated with an acid as a catalyst which activates and hardens an organic binder for binding the granular material.

A process for the production of a mineral foam suitable for its use as refractory material includes (i) separately preparing a slurry of cement and an aqueous foam, wherein the cement slurry comprises water (W), an aluminate cement (C) and a lithium salt; (ii) contacting the slurry of cement with the aqueous foam to obtain a slurry of foamed cement; (iii) adding lithium salt during or after stage (ii); (iv) casting the slurry of foamed cement and leaving it to set.

The invention relates to uniformed concrete comprising, in percentages by weight, (d) 87% to 98% of particles comprising more than 90 wt.-% alumina, (c) 1% to 7% silica fume particles, (f) 1% to 8% particles of a hydraulic cement, the fraction of said particles having a size less than 40 m being distributed as follows, in percentage by weight in relation to the weight of the unformed concrete: fraction <0.5 m: 4%, fraction <2 m: 5%, fraction <10 m: 19%, fraction <40 m: 34%-52%, fraction between 2 m and 40 m: 26.5%-34%,
the concentration of Zro2, in percentage by weight on the basis of the uniformed concrete, being less than 2%, and the concentration of organic fibres, in percentage by weight on the basis of the uniformed concrete, being less than or equal to 0.03%.

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.

A lightweight micro-closed-pore corundum composite refractory and a method preparing the same, wherein raw materials of the refractory comprise 95-99 parts by weight of -Al.sub.2O.sub.3 micro-powder and 1-5 parts by weight of dolomite clinker; and additives of the refractory comprise 2-15 parts by weight of nano alumina sol, 5-15 parts by weight of a carbohydrate polymer, and 30-50 parts by weight of an organic alcohol. and the lightweight micro-closed-pore corundum composite refractory is prepared by: mixing and wet grinding the raw materials and the additives to obtain a slurry; placing the slurry in a mold, keeping the mold at 15-25 C. for 6-12 hours and then keeping the mold at 60-90 C. for 6-12 hours, then demolding; drying a demolded green body at 110-200 C. for 24-36 hours, and keeping the green body at 1800-2000 C. for 2-5 hours. A method preparing a lightweight micro-closed-pore corundum composite refractory is also provided. The lightweight micro-closed-pore corundum composite refractory of the present invention has characteristics of low bulk density, small average pore size, high closed porosity, low thermal conductivity, strong thermal shock resistance, abrasion resistance and slag resistance.

An unfired, refractory molded body (1), especially a plate, especially for thermal insulation of molten metal and/or an ingot solidifying from molten metal, that includes a binding agent matrix (2) of a set binder and aggregate grains (3) of biogenic silicic acid, preferably of rice husk ash, which are incorporated into the binding agent matrix (2), wherein the binding agent matrix (2) consists of silica gel, as well as a process for its production and its usage.