Experimental Study of Synthesizing Cordierite from High-Alumina Fly Ash

Synthesis of cordierite with fly ash has good prospects for industrial development. Whereas this technique is restricted for higher cost derived from adding Al2O3 to the common fly ash in order to increase a deficient alumina composition to stoichiometric cordierite. In the paper, by using the mixture of high-alumina fly ash collected from the Jungar power plant and talc powder, the cordierite was synthesized directly. The physical properties of cordierite samples were measured using Archimedes' method, and the phase of cordierite samples was analyzed by XRD and the microstructure of the cordierite samples was observed by SEM. The results showed that based on the proportion of the fly ash and talc powder designated as 1.6288 : 1 (the as-received fly ash to talc powder) and 1.515 : 1 (the treated fly ash to talc powder) respectively, the cordierite samples yielded from the mixtures were manufactured at 1350 degrees C similar to 1370 degrees C. The physical properties of the sintered cordierite could meet the quality requirements of cordierite, and the major crystalline phases in the sintered samples were a-cordierite (indialite) with almost no glassy matters. The sintered samples derived from the as-received fly ash were mainly composed of cordierite with a lesser amount of anorthite and spinel. Comparatively, the ones generated from the treated fly ash consisted predominantly of cordierite with minor crystals of mullite and spinel.