jismart2019044: Study on the effect of wet surface modification of Fly ash on characterization

Abstract

Effective utilization of Fly ash (FA), an industrial by-product of coal-fired power generation, is an urgent issue.In the flotation method, which is one of the reforming techniques of FA, FA is slurried in advance and stirred. In order to clarify the relationship between the preliminary stirring and the reactivity of FA, particle analysis of FA was performed.The morphology of the hydrated product and the reaction phase in the paste specimen was observed with a field emission scanning electron microscope (FE-SEM).The main constituent element ratio of calcium silicate hydrate (C-S-H) in contact with the reaction phase was evaluated using an energy dispersive X-ray analyzer (EDS).Even in the same ash species, different reaction phases were generated depending on the pre-stirring conditions, and the reaction phase changed with the progress of the reaction.In addition, unmodified FA paste specimens tend to have a low Ca / Si ratio and a high Al / Ca ratio in the vicinity of the FA particles at the initial age, and FA paste specimens with pre-stirring tend to do so. Because of the relatively small amount, there is a possibility that strength development can be expected at long age.