| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a board uniformly colored black by compacting a raw material mixture, containing a hydraulic material, coal ash finely pulverized to have a specific Blaine value or higher and reinforcing fibers into a mat body by spreading the mixture on a plate and pressing, curing the mat body. SOLUTION: As the hydraulic material, portland cement, alumina cement, etc., are used and woody reinforcing materials, organic synthetic fibers and inorganic fibers are desirably used as the reinforcing fibers. The coal ash to be used is fly ash or bottom ash having >=7,000 cm2/g Blaine value and is prepared by finely pulverizing for >=12 hours usually using a ball mill or a vertical mill until it reaches such a state that carbon fine particles are adhered to the surface of the coal ash to function as a black pigment. The raw material mixture is prepared by blending 20-60 wt.% hydraulic material, 5-15 wt.% reinforcing material and 10-40 wt.% coal ash. The pressing is preferably carried out under 20-50 kgf/cm3 compression pressure, the preliminary curing at 40-90 deg.C for 4 hours or longer, the main curing at 130-180 deg.C for 6-15 hours in an autoclave.</p> |
