Development of superduty silica Bricks with indigenous raw materials

Abstract

Development of superduty silica with indigenous raw materials which are known to be abundant was investigated. Three samples of quartzites from Jamda, Mihijam and Hyderabad were studied. This study has revealed that crypto-crystalline variety of Jamda quartzite which is very low in alumina, can be used successfully for the manufacture of superduty silica brick by proper granulometric control, high pressure forming and firing under strictly controlled conditions. The product thus obtained has the requisite properties of a superduty quality brick. The addition of low aluminium quartztite fines to graded Mihijam quartzitedoes not effect any tangible improvement in the physical properties of silica brick specimen made out of the mix. However, appreciable improvement in porosity, permeability, refractoriness underload, etc. could be attained by proper forming and by improved processing methods as adopted in the case of Jamda quartzite. Low alumina bricks and even addition of fines from this quartzite to Mihijam quartzite did not bring out any improvement in the silica brick made from Mihijam quartzite, probably due to very friable nature of this low alumina quartzite from Hyderabad. (Mr. Gurubux Singh Minhas, Senior Scientific Assistant; Mr. H.V. Bhaskar Rao, Scientist; National Metallurgical Laboratory, Jamshedpur)