The effect of fused magnesia addition on the properties of chamotte refractories

This investigation reports the effect of magnesia addition on the properties of chamotte (fireclay) refractories. Five compositions were prepared containing 0, 3, 5, 7 and 9 w/o fused magnesia addition. Before mixing, powders were prepared by grinding and milling of fireclay and magnesia refractory bricks to pass through 300 micron. Five samples were prepared for each composition and all samples were shaped using uniaxial pressing as rectangular bar. Sintering was carried out at 1400 degreesC for one hour in air. Characterisation tests were performed including firing shrinkage, bulk density, apparent porosity and flexural strength test at room temperature. Microstructural examination by optical microscopy, and phase analysis by XRD were also carried out.