Development of Superduty Silica Brick with Indigenous Raw Materials

Abstract

Development of superduty silica bricks with indigenous raw materials which are known to be abandant,was investigated in the National Metallurgical Laboratory. 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 super-duty quality brick. The addition of low alumina quartzite fines to graded Mihijan quartzite does not affect any tangible improvement in physical properties of silica brick specimen made out of the mix .However, appreciable improvement in porosity permeability ,refractoriness under load etc. could be attained by proper forming and by improved processing methods as adopted in the case of Jamda quartzite. Low alumina quartzite from Hyderabad was not found suitable for making super-duty bricks and even the 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 the very friable nature of this low alumina quarter from Hyderabad .