Zeolite–carbon composites prepared from industrial wastes: (I) Effects of processing parameters

Zeolite–carbon composites were synthesized by a combined process of calcination and carbonization at 600–850 °C in N2 atmosphere followed by a hydrothermal treatment in alkaline aqueous solution from industrial wastes of coal fly ash and sawdust mixtures. The effects of processing parameters on the phase compositions, microstructure and the physical properties of the composites were investigated. With addition of Na2CO3 as an activator, the zeolite–carbon composite calcinated at 600 °C and hydrothermally treated at 120 °C in 2 M NaOH aqueous solution consisting of zeolite Na–Pl and zeolite Na–X phases yielded a specific surface area of 84 m2/g and a total pore volume of 0.15 cm3/g, which were higher than some commercial building materials. The resulting composites with micropores and mesopores have potentials as low cost and high value-added environmental materials, such as metal ion and organic pollutant adsorbents, building material with humidity-controlling capacity and so on.