Patent ID: 8657950

Claim:
An inorganic material board, which is a cured mat formed by dehydrating a slurry including 30 to 53 wt % of blast furnace slag, 2 to 5 wt % of gypsum having an average particle size of 200 to 2000 μm, 5 to 11 wt % of alkaline material, 5 to 15 wt % of reinforcing fibers, and 31 to 50 wt % of inorganic admixture with respect to a total solid content, and in which a weight ratio of the blast furnace slag to the gypsum to the alkaline material is 1:0.05 to 0.15:0.15 to 0.35, wherein the blast furnace slag is granulated blast furnace slag, the gypsum is recycled gypsum obtained by crushing plasterboard waste, the inorganic material board contains one or more component selected from the group consisting of coal ash and papermaking sludge incineration ash, as the inorganic admixture, and the inorganic material board contains wastepaper as the reinforcing fibers.