Synthesis of α-cordierite (indialite) from flyash

The high temperature hexagonal form of cordierite, indialite, has been synthesized using flyash as one of the starting raw materials, x-ray diffraction studies indicated the presence of only cordierite phase. There were no detectable minor crystalline phases though mullite was present in the starting flyash raw material. The properties of the synthesized material including thermal expansion compare well with the values of conventional cordierite. The presence of needles were observed within the fine grained matrix in the microstructure.