Preparation and Properties of Ceramic Materials from Coal Fly Ash

The development of technologies for utilization of coal fly ash, the huge accumulations of which represent a serious environmental threat, is an essential problem. Obtaining of ceramic materials can be a promising way of fly ash utilization. The article presents the results of sintering behavior study of Vorkuta thermal power plant fly ash at 800–1250 °C. Apparent density, water absorption, open porosity, and crushing strength of sintered samples were determined. Experiments have shown that sintering occurs at temperatures of 1050 °C and above. Ceramics obtained at a firing temperature of 1150 °C is characterized by the highest values of apparent density and crushing strength and low values of water absorption and porosity. At 1200 °C and above there is an increase in sample dimensions (foaming) with the formation of internal pores, i.e. a porous ceramics is obtained. It has been shown that the pressure and the sintering temperature affect the characteristics of ceramics: apparent density, water absorption, porosity, and crushing strength. According to its technological characteristics, the obtained materials can be used for the production of building ceramics.