Application of Fly Ash and Coal Gangue for Preparing High-Class Solid Insulating Brick by Roasting at Low Temperature Conditions

Abstract: The fly ash and coal gangue were used as main raw materials to roast solid insulating brick.Lower than solid clay brick (300 °C) which belongs to low temperature roasting , roasting time cycle is 24 h ,the ratio of fly ash and coal gangue is 60% :35%. the B7 admixing expanded pearlite compressive strength is 30.25 MPa . Strength reach general clay brick MU30 high-class level .Thermal coefficient of conduction is 0.4 W/(m.K), lower than general clay brick thermal coefficient of conduction 0.78 W/(m.K); In addition , B7 XRD pattern has evident quartz、mullite diffraction character peak and TGA-DTA pattern between 900°C~1200°C, following temperature rise, green body heat-absorbing , begin melt 、glass reduction .The result is high in strengths . SEM scanning show : after being roasted in 950°C , globular solid glass bead 、pearlitic drusy pearlite 、flocculation aluminosilicate phase and so on , raw materials particle interstices were filled with viscous hyaline, so that B7 turned out high strengths . Acidproof、alkaliproof、freezing test and strengths results show: the lasting quality of solid insulating brick was best.