Highly efficient adiabatic and flame-retardant SiO2 aerogel and its fibrous composite for high-temperature applications within underground chambers

Abstract

In the present scenario, the underground chambers of deep metal mines are plagued by excessively high temperatures, and the existing adiabatic materials have proven to be inadequate in addressing this challenge. Considering these issues, this study introduces an innovative adiabatic and flame-retardant SiO2 aerogel-based fibrous composite designed specifically for underground applications. The optimal preparation method for SiO2 aerogel preparation was identified through monomer and orthogonal experiments, ultimately achieving a low thermal conductivity coefficient of 0.028 W/(m·K). Subsequently, through integral moulding, a composite material was developed, incorporating the optimal SiO2 aerogel as a precursor along with ceramic fibres. The resulting ceramic fibre/SiO2 aerogel exhibited an increased thermal conductivity coefficient of 0.061 W/(m·K). When subjected to a high-temperature combustion source of approximately 700 °C, the temperature of the upper surface of the sample was maintained at 131.9 °C and its mass loss rate was a mere 1.2%, exhibiting strong adiabatic and flame-retardant capabilities of the composite material. Moreover, the composite material exhibited good hydrophobic, adsorbent, and mechanical properties, making it well-suited for underground chamber applications. The research conducted on SiO2 aerogel and its adiabatic ceramic fibre composite not only holds theoretical significance by guiding the development of improved adiabatic materials but also provides practical engineering solutions for mitigating heat transfer through raw rock and reducing chamber temperatures in underground mining environments.