Patents
The invention relates to a process for the manufacture of dense high alumina refractory aggregate from sillimanite sand-based minerals. This has been made possible by providing a process wherein the starting material is a novel composition consisting of sillimanite sand minerals, ZrO2 and TiO2. The process involves proper milling of the novel mixture and single firing at a temperature between 1500° to 1600°C. The novel composition helps intensify the densification through liquid phase sintering and controls the glassy phase and improves the high-temperature properties. The aggregates produced have high alumina content, in the range of 55 to 62% Al203, and have above 98% densification, average grain size of 5 to 10µm, hot modulus of rupture at 1250°C is 1700 to 2100 kg/cm2. Dense high alumina refractory aggregates are in great demand in refractory industries.