Conversion of Aluminium Industry Wastes into Glass-Ceramic Products

Wastes from the aluminium industry such as red mud from the alumina refinery, fly ash from the captive power plant and spent pot lining from the smelter, have been successfully converted into glass-ceramic products. The process involves addition of a small quantity of glass former along with traces of nucleating agents to aid crystallization, to a specific mixture of red mud, fly ash and spent pot lining, followed by melting at around 1300°C and vitrification by cooling. The resultant glass is then converted into a glass-ceramic by a suitable heat treatment at around 700 – 750°C. The glass-ceramic products show excellent wear resistance, besides possessing an aesthetic appearance. The major application foreseen for such products is as decorative tiles in the building industry.