Abstract: Porous ceramic material is prepared by means of chemically foaming process and taking coal gangue hollow sphere and glass powder as the main raw material, using calcium carbonate(CaCO3) as foaming agent and the properties of porous ceramic materials are investigated. The experimental results show that homogenous microstructures of large pores could be obtained by adding carbonates and the apparent density decreased obviously with increasing the sintering temperature, apparent density values of 190 kg/m3 at a low sintering temperature (670 ℃); the diameter of the porous gradually increases with increasing the sintering temperature, the water absorption decreased firstly and then has a small rise .In addition, the apparent density has a great influence on thermal conductivity, with the apparent density change from 520 kg/m3 to 190 kg/m3, the coefficient of thermal conductivity is obvious downtrend from 0.103 W/(m•K) to 0.037 W/(m•K). The results of this study could initiate a new way for utilization of coal gangue to achieve significant environmental, economic and social benefits.

Key words: apparent density, coal gangue hollow sphere, coefficient of thermal conductivity, foam ceramic