US Patent 7341620 Fire-insulating wall covering and a preparation method for same

A sound-absorbing and fire-insulating wall covering includes, a cured mixture of: (i) 5-20% by weight mineralized wood fibre; (ii) 20-60%/by weight sand with an SiO2 content of less than 5% by weight and a greywacke content of at least 30% by weight; and (iii) 20-50% by weight cement. A method of preparing a fire-insulating wall covering includes a step of mixing, relative to the cured weight, 5-20% by weight mineralized wood fibre, 30-60% by weight sand with an SiO2 content smaller than 5% by weight and a greywacke content of at least 30% by weight, and 20-50% by weight cement. Then 10-30% by weight water is added. Thereafter the mixture is cured to form the fire-insulating wall covering.