Effect of ZrO2 on the alkali resistance and mechanical properties of basalt fibers

We have studied the effect of zirconia additions on the properties of basalt glasses and fibers. The solubility limit of ZrO2 in basalt glasses is determined to be 7.1 wt %. Fibers produced from modified basalt glass contain both tetragonal and monoclinic zirconia. The highest ZrO2 concentration in basalt fibers is 3.1 wt %. We have determined the fiber drawing temperature ranges and assessed the tensile strength and alkali resistance of the fibers. With increasing ZrO2 content, the tensile strength of the fibers (d = 11−12 μm) decreases from 1.8 to 0.6 GPa. The addition of less than 3.1 wt % ZrO2 increases the alkali resistance of the basalt fibers by 37%. The addition of more than 3.1 wt % ZrO2 to the glass batch reduces the alkali resistance and tensilestrength of the basalt fibers.