Abstract:

Based on the micro-scale heat and mass transfer mechanism , a new-type porous thermal insulating material was prepared hy means of microwave heating and expanding , with expanded perlite as the aggregate , sodium silicate as the adhesive , and calcined kaolin , CaCO₃ and Li-hentonite as the additives. The effect of heating and expanding method on the performance of the prepared material was then analyzed , and the variation of thermal conductivity with component proportion was investigated. The results indicate that the optimal mass ratio of expanded perlite/ sodium silicate/Li -hentonite/ calcined kaolini CaCO₃ is 46: 36: 13: 3: 2 , that the contents of expanded perlite and sodium silicate are two main factors influencing the thermal conductivity of the product , and that the additions of Li-hentonite , calcined kaolin and CaCO₃ can effectively improve the mechanical strength and water resistance of the prepared porous thermal insulating material.

Key words: thermal insulating material, preparation, property, microwave heating, thermal conductivity