Method of preparing insulating refractory products and the product thereof

Claim 1

Method for preparing an insulating isotropic refractory product resistant to thermal shock and resistant to the corrosive action of molten metal, having high porosity, having a high coefficient of thermal conductivity of the order of 0.1 K cal/m/° C/hour, a Young's modulus of the order of 20,000 kg/squ. cm, a high tensile strength of the order of 12 kg/squ. cm, constituted by refractory fibers dispersed in a cement, characterized in that said product is produced by the following sequential process operations: dry dispersing a mixture consiting of calcium aluminate cement mix and refractory fibers composed of less than 15% silica content, the percentage of fibers in relation to the total weight of the dry mixture being at least equal to 60%, forming concrete by adding water to the dry mixture and placing in a mold, stripping the concrete from the mold after the beginning of the setting, drying the concrete outside the mold at a temperature increase of 10° per hour up to 300° C with a prolonged heat stage of several hours at 100° and 300° C, increasing the temperature of drying with the same 10° C per hour rate from 300° to 800° C, and baking the concrete at 800° C in air to form a chemical bonding between the refractory fibers and the calcium aluminate of the cement.