Composite silica aerogels were prepared using sodium silicate and ceramics fibers. The thermal conductivities of these composites were investigated to determine how effective they would be as thermal insulation. As temperature increased to 400oC, the thermal conductivity of these composites only increased from 0.0266 to 0.0572 W/(m·K). This indicates that these composites which have good structural and mechanical properties would be good thermal insulators during thermal processes....