The Expansion Mechanism of Artificial Aggregate from Coal Fly Ash --Artificial aggregate from fly ash (2nd Report)—

摘要

To produce an artificial aggregate ofstable quality, investigations of the expansion Isinter mechanism of coal fly ash are required. Thepurpose of this study is to clarify the influence ofcarbonecious substances on pellet expansion by firing,especially related to the atmospheric conditions.The study revealed two types of expansion. One relatesto unburned coal fragments which exist separately fromash particles. In this case, large pores are formedaround an oxidization front in the expanded pellet,accompanied by a macroscopic double-core structure inthe sintered zone proceeding from outside. The otherrelates to very small coal fragment trapped in glassyspheres. Because the spheres in the pellet aredistributed homogeneously, small pores are alsoinflated homogeneously with producing C0_2 and CO.These gasses are generated by a reaction of theunburned coal fragments and oxygen in the glassy structure.