Preparation and microstructure analysis of fly ash continuous fiber.

A new type of inorganic fiber-fly ash continuous fiber was innovatively developed in this study to alleviate the problems of low comprehensive utilization rate and lacking of high-value utilization means of industrial solid waste fly ash. The melt flow temperature and macro-mechanical properties of different samples were studied. The results showed that with the increase in acidity coefficient index (MK), the melt flow temperature decreased first and then increased, and the lowest value was 1340 °C when MK was 3.1. Meanwhile, with the gradual increase in MK, the tensile strength and elastic modulus of monofilament increased first and then decreased. When the MK was 3.8, the tensile strength and elastic modulus of fiber monofilament reached 2064 MPa and 16.7 GPa, respectively. According to the results of XRD, TG-DSC, FTIR and SEM microstructure analysis methods, it is found that the macro-mechanical properties of fibers are closely related to the chemical composition and phase structure evolution of raw materials. After melting at high temperature, the samples with high MK form a dense three-dimensional glassy network structure, which leads to the higher mechanical strength of the fibers. However, in the samples with lower MK, the vitreous network structure is loose, which reduces the mechanical properties of the fiber. Finally, the MK range (2.5–3.8) for preparing high-performance fly ash fiber was proposed in this paper. In this range, the synthesized fly ash continuous fiber has low melting temperature and excellent mechanical properties, which has a potential of industrial application. [ABSTRACT FROM AUTHOR]