A comparative study of insulation refractories with special reference to thermal conductivity

Thermal conductivity and other physical properties of insulation refractories collected from various indigenous sources together with an imported sample, for comparison, have been studied with a view to help in the formulation of standard specification for insulation refractories at the request of Indian Standards Institution. The thermal conductivity apparatus was fabricated at the National Metallurgical Laboratory based on A.S.T.M. design. Due to the large number of conclusions, it appears probable that in the case of backing insulation the thermal conductivity increases with alumina content whereas with type II insulation brick , the reverse trend is noticed. From this study of indigenous samples, it appears that there are few samples which could be classified as superior to type II IS 2042-1963. But unlike American and other classification in which these bricks can fit in. Amongst the samples studied so far, there is only one silica based sample, which conforms, to type III of IS 2042-1963. (Messrs B.M. Dutta and H.V. Bhaskar Rao, National Metallurgical Laboratory)