Effect of particle size of calcium aluminate cement on volumetric stability and thermal shock resistance of CAC-bonded castables

The distribution and size of in-situ CA6 is related to CAC particle size in CAC-bonded corundum-based castables and would influence the properties of the castables. In order to investigate the influence of CAC particle size on the properties of CAC-bonded castables, CAC was milled for 2 h to reduce particle sizes. The properties of CAC-bonded castables with different CAC particle sizes were investigated in terms of demoulding strength after curing at 30 °C, drying strength after drying at 110 °C and, in particular, volumetric stability and thermal shock resistance after firing at 1450 °C, respectively. The results indicate the volumetric stability and thermal shock resistance of the CAC-bonded castables were improved by replacing unground CAC (D50 = 12.39 μm) with ground CAC (D50 = 1.36 μm) because the incorporation of ground CAC produced smaller-sized CA6 with more uniform distribution after firing at 1450 °C.