Investigations on the manufacture of Graphite Crucibles - Interim Report No. I: Suitability of certain Indian clays as bonds for Graphite Crucibles

Abstract

Graphite crucibles were first manufactured in India during World War II, to fulfil a demand that was suddenly created by the complete cessation of imports. With the return of normal conditions, Indian crucibles had again to face competition of established foreign products and it still remains the position that approximately five hundred tons of foreign graphite crucibles per annum valued at one million rupees are finding market in India. As graphite crucibles are vital to our foundry industry it is undesirable to depend on foreign crucibles, supplies of which might be completely cut off in the case of national emergency, it is imperative that the indigenous graphite crucibles industry should be put on a sound basis. With this end in view, the Council of Scientific and Industrial Research has sponsored a comprehensive research programme on graphite crucibles in the Refractories Division of the National Metallurgical Laboratory. The research work envisaged comprises: (1) Study of certain Indian clays for application as bonds in graphite crucibles,(2) Study of Indian graphite with a view to their utilisation in crucible making, (3) Development of suitable clay bonded and carbon bonded crucible bodies, utilising imported crucible- grade graphite at the first instance and later indigenous graphite if possible, and(4) Development of proper protective coatings-internal as well as external for graphite for graphite bodies. In this interim report, the suitability of certain Indian clays as bonds for graphite is discussed.