Development of Castables with High Thermal Shock Resistance and Volume Stability

Abstract: Vacuum Arc Degassing (VAD) ladle covers are a vital item for steel production through VAD units. Under prevailing operating conditions of VAD, ladle cover refractories need to sustain high thermal shock and a corrosive environment. Their operational conditions and lining patterns also demand a high volume stability of the refractory material. A composition of a high alumina castable suitable for the manufacture of pre-cast blocks was designed to obtain the desired properties. It was found that castables with an optimum amount of Cr2O3 in combination with the proper deflocculant and dispersing agents were the most suitable. Based on the study, pre-cast blocks were manufactured with the castable developed and tried in VAD ladle covers of ASP, SAIL. It was observed that pre-cast blocks of VAD ladle covers were highly stable under the severe VAD operating conditions and have the potential to result in a good lining life.