Calcium silicate based high efficiency thermal insulation

The preparation by hydrothermal synthesis of a high efficiency calcium silicate based thermal insulation is described using raw material mixes of silica, bentonite, and magnesium acetate or acetic acid. The materials were reacted in a high pressure autoclave at 200-250 degreesC resulting in a product consisting of cenospheres of needle-like xonotlite crystals and some tobermorite. Properties including density, strength, microstructure, thermal stability, and water absorption and water repellence are presented.