Effect of Al2O3/SiO2 mass ratio on the structure and properties of basalt glass

Basalt fiber is extensively utilized across diverse industrial sectors. However, its performance exhibits inherent variability due to the heterogeneous chemical composition of natural basalt ore. This study systematically investigated the influence of Al 2 O 3 /SiO 2 mass ratio on the structure and properties of basalt glasses derived from four distinct geological deposits. Basalt samples were melted at 1500 °C for 2 h and subsequently rapidly quenched to form glass. High-temperature viscosity, Raman spectroscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy were employed to characterize the properties of basalt glass. The results demonstrated that an increasing Al 2 O 3 /SiO 2 mass ratio in the glass enhanced the degree of silicate network polymerization. This enhancement was attributed to the incorporation of Al 3+ into the network as four-coordinated [AlO 4 ] 5− tetrahedra, which facilitated the conversion of non-bridging oxygen species into bridging oxygen, thereby improving network connectivity and structural compactness. A quantitative correlation between the Al 2 O 3 /SiO 2 ratio and key structural parameters of the glass was established, providing essential guidance for optimizing basalt fiber production through raw material selection and precise process control.