Dense and Porous Ceramic Materials Made from the Slack Coal of the Inta Deposit

Dense and porous heat-insulating ceramic materials have been made from flotation tailings of slack coal at the Inta Group Concentration Plant. The thermic behavior and nature of the change in the phase and chemical compositions on firing in at temperatures range from 800 to 1280°C were studied. On firing, magnetite is sequentially oxidized, kaolinite is amorphized, carbonates are dissociated, layers in layered silicates are compressed, cristobalite and spinel are formed at 1100°C, mullite is formed at 1150°C, and the content of the x-ray amorphous phase increases. Dense ceramic materials were obtained at firing temperatures 800 – 1150°C and porous materials at temperatures from 1200 to 1280°C. The physicomechanical and technical characteristics of the obtained ceramic materials were studied. Porous ceramic fired at 1280°C is a heat-insulating material with heightened thermal conductivity.