Mechanism on Activation of Coal Gangue Admixture

Coal gangue, an industrial waste, is rich in silicon and aluminum phase may be used as a mineral admixture concrete after moderately stimulating activity, allowing for efficient solid waste utilization. This study mortar strength activity evaluation method to investigate single or compound activation methods find the optimum of coal gangue. FLIR, XRD, SEM were mechanism different modes, providing theoretical foundation gangue admixture. Results showed that mechanical ball milling, microwave, chemical activator could activate composite effect was best. The fineness powder more than 300 mesh, according optimal compounding method. Accordingly, particle surface smooth, internal defects reduced, microwave irradiation temperature 700°C–800°C, causing particles form bonding gradually agglutinate densify. Meanwhile, layered structure kaolin minerals destroyed, significant amount glassy active SiO2 Al2O3 produced, enhancing gel ability Finally, 8% Ca(OH)2 added production specimens, which increased alkalinity slurry, stimulated rapid cracking secondary hydration enhanced mortar. At this time, rate reached highest, 90.5%.