Densification behaviour of bioceramic tiles from bioresidue

An attempt of vitrified bioceramic tiles was made from bioresidue material of rice straw ash as a source of bio-silica. The high purity nanosilica was synthesized from rice straw ash (RSA) using sol-gel method. Biosilica can be substituted for quartz in ceramic tiles to improve the strength and mechanical behaviour. Quartz was placed instead of 5 wt% and 10 wt% biosilica (BS) in porcelain ceramic tiles. All the specimens were sintered at 1250°C and mechanical parameters were carried out to determine their physico-mechanical properties. The developments of microstructural and phases analysis on the specimens were carried out using SEM and XRD techniques. Rod shaped mullite crystals with low aspect ratio were found distributed in the microstructure. Mullite and quartz phases were observed in the XRD pattern. When the porosity nearer to zero correspondingly compressive strength becomes maximum and the strength was correlated to the ultrasonic pulse velocity.