The melting temperature distribution of fly ash used to prepare fiber is a key to the composition ratio for reducing the melting temperature. Using X-ray fluorescence spectrometry and ash fusion point determination meter

the compositions and fusion temperature of five kinds of fly ash samples were measured. Ternary phase diagram with Al2O3+SiO2

CaO+MgO

Fe2O3+TiO2 for three-phase coordinate was obtained based on the experimental results in the present study and the data of compositions and melting temperature of 117 fly ash samples in literature. Meanwhile

the fly ash melting temperature profile was derived from the zoning method according to different melting temperature. With the effort of distinguishing the compositions of fly ash in low-melting zone

the regularities of its compositions and melting temperature have been established. It has been proved that the compositions and distribution of fly ash in the low melting regions (FT<1350℃) are well consistent with the low melting point regions of 1350℃ in CaO-Al2O3-SiO2 ternary phase diagrams where the minor components are converted to the equal charge of main components

leading to a method of reducing the melting temperature of the fly ash with high melting temperature.