Abstract: A process of using a thermally insulating board, made of a homogeneous mixture of expanded perlite particles and cellulosic and/or mineral and/or ceramic fibers, bonded together, comprising placing on the surface of a molten steel mass, in direct contact with the surface, so as to cover substantially all the surface. According to a preferred embodiment, the board consists of 51 to 80% by weight of expanded perlite particles, 15 to 39% by weight of cellulosic and/or mineral fibers and 5 to 10% by weight of binder.

Abstract: A process for preparing a porous ceramic thin film which comprises applying an anhydrous solution containing an organometallic compound and a multifunctional organic compound to a substrate, and thermally decomposing the compounds. The porous ceramic thin film prepared by the process has pores of not more than 10 .mu.m in pore size, and is useable as for materials of various sensors.

Abstract: Unfired refractory structural member in the form of a plate for the expendable lining of metallurgical vessels, especially for tundishes used in continuous steel casting, and comprising magnesia sinter and possibly olivine with a grading of 30-45% by weight under 0.09 mm, and 55-70% by weight 0.09 to 4 mm, including 20-40% by weight over 1 mm; cork or granulated ceramic fibers as a pore-forming material; an inorganic binder; and possibly other additives. This refractory structural member has good strength, a small ignition loss, a low content of volatile hydrogen-containing substances, a favorable peeling behavior, and good resistance to slag and molten steel.

Abstract: An aqueous preparations of a gel-like consistency, containing(A) 1-15% by weight of hydrophilic polyurethanes,(B) optionally up to 3% by weight of hydrophilic polymers which are water-soluble or capable of swelling in water, based on unsaturated monomers and/or modified cellulose derivatives,(C) optionally up to 2% by weight of surface active agents,(D) optionally up to 30% by weight of powder, and(E) 0.3-30% by weight of oil.The aqueous preparation is useful as a porosifying agent in the production of porous ceramic bodies.

Abstract: An aqueous preparations of a gel-like consistency, containing(a) oils in quantities of from 0.03 to 30% by weight,(b) water-soluble or swellable vinyl polymers in quantities of from 0.2 to 10% by weight,(c) water-soluble or swellable polymers based on natural substances in quantities of from 0.01 to 5% by weight,(d) surfactants in quantities of from 0.01 to 2% by weight and optionally(e) inorganic or organic powders in quantities of from 0.5 to 30% by weight.The aqueous preparation is useful as a porosifying agent in the production of porous ceramic bodies.