Reasons for crack propagation and strength loss in refractory castables based on changes in their chemical compositions and micromorphologies with heating: special focus on the large blocks

Among the most significant problems in industrial refractory manufacture, especially of monolithic refractories, are the formation of cracks and loss of strength in green bodies or during heating of the refractory castables. These issues could be due to changes in their chemical compositions and micromorphologies with heating. This paper reviews the problems due to the addition of each raw material to a batch of refractory castables after curing and drying at 110°C as well as due to the firing of castables containing these materials. In the final section, suggestions are made for the production of large, heavy-weight blocks (e.g. electric arc furnace roofs) without the presence of calcium aluminate cement (noncement electric arc furnace roofs) to prevent cracking in large blocks