Refractory castables based on barium aluminate cements

Abstract

Abstract Three aluminous cement compositions containing different proportions of barium aluminate were prepared from mixtures of calcined alumina, Egyptian barite, and limestone, by sintering briquettes at around 1600°C. The sintered bodies were ground to produce a cement powder of suitable fineness in which the predominant phases were found to be barium aluminate and calcium dialuminate. These cements were found to possess satisfactory cementitious behaviour and high refractoriness. Refractory castable compositions, based on the prepared cements and using sintered magnesia as aggregate, were formulated and evaluated for their physical, mechanical, and refractory properties. High strength and low shrinkage characterise the castable shapes in the cured, dried, and fired states. Such barium aluminate containing castables could be used effectively for lining structures subjected to very high temperatures.