Abstract: Lightweight insulating boards in accordance with the present invention comprise Portland cement, fibers and fillers including:(a) 50-75% by weight of cement,(b) 0-5% by weight of cellulose fibers,(c) 0.5-4% by weight of alkali-resistant fiber material,(d) 5-20% by weight of mica,(e) 5-20% by weight of light filler and(f) 8-25% by weight of hydrated lime.They are shaped into boards from a suspension and are set at least 15 days, and preferably 28 days. The insulating boards of the present invention meet all of the requirements set for such materials regarding flexural strength, incombustibility, and the like.

Abstract: A material of the board type for various thermal shielding applications preferably contains 10 to 50% by weight of a mineral substance based on silica or silicates in fibrous form prepared from the fused substance, 10 to 70% by weight of clay, if necessary 10 to 60% by weight of a mineral having a needle-like crystal structure, and a small proportion of an organic binder for maintaining the mineral constituents in a coherent structure at least during fabrication, conversion and utilization of the end product. The total quantity of organic substances does not exceed 8% by weight of dry substances. The material has high temperature strength by virtue of the combination of an organic binder with a mineral binder and also has good dimensional stability.