Effect of percentage (mass %) of coal on the mechanical and thermal behavior of insulating fire bricks manufactured by burnout process

Under this present study, thermal and mechanical behaviors dependence of insulating fire bricks (produced by burnout process) on coal percentage (mass %) were investigated. Waste coal powders or coal dust were collected from mines, transport vehicles, storage areas etc. Specimen insulating bricks were produced by uniaxial pressing in a steel mould. The main materials were fireclay consisting of silica (63.81 mass %), alumina (27.01 mass %), iron oxide (5.99 mass %) and varying percentage (from 5 mass% to 20 mass %) of coal as combustible additives. The specimens after several hours of drying at ambient temperature (30°C), oven dried at 110^oC(10 hours) and then fired in a furnace at 1050 ^oC (6 hours). The investigation showed that for a fixed coal particle size (20 to 100 μm), percentage of porosity increases whereas apparent density, cold crushing strength and thermal conductivity decreases with increasing percentage of coal.