Microwave heat treatment on red sediment sillimanite–zircon–alumina composites for fused zirconia–mullite products

The present paper shows a convenient and eco-friendly microwave heating method for the synthesis of fused zirconia mullite formation on combining placer sillimanite and zircon with the mixtures of alumina powder and reducing agent silicon carbide powder with lesser time. The X-ray diffraction data field-emission scanning electron microscope spectrum and scanning electron microscopy/energy-dispersive X-ray spectroscopy analyses in this paper predict that alumina is rich in mullite grains, whereas the grain boundary region becomes rich with zirconia after microwave process. The presence of small percentage of zirconia in the intragrain region reveals that mullite compound is surrounded by well-compacted zirconia. These data also reveal the presence of fused zirconia mullite phase along with crystalline SiC and monoclinic zirconia in the composites.