HIGH-TEMPERATURE RESISTANT, POROUS AGGREGATES, PROCESS OF PRODUCING THE SAME AND MOULDED PARTS MADE THEREFROM

摘要

A high-temperature resistant, porous aggregate, a process for producing the same and products made therefrom are disclosed, which are useful to prepare highly effective heat insulators available as mixtures or as moulded products that have applications in the construction of industrial ovens and of high-temperature installations. The aggregate on the basis of calcium aluminates and/or magnesium aluminates and/or their mineral derivatives having one or several components contains 0.20 to 0.95 parts in volume of micropores, whereas more than 60 % of the micropores have less than 40 mu m in diameter. The porous aggregate is produced by mixing the corresponding oxidic or hydroxidic finely ground raw materials with 0.1 to 4.0 parts in mass of water, in relation to one part in mass of dry raw materials. The homogeneous mixture is then treated by autoclave at temperatures higher than 125 DEG C, for 1 to 25 hours, the solidified mass is dried, then sintered at temperatures equal to or higher than 1000 DEG C for 1 to 25 hours and the sintered product is transformed into aggregates.