The influence of Alkaline Granite addition on Ceramic Body Sintering

Abstract

Alkaline-granite was added on the ceramic bodies sintering at different temperatures from 1140 O C to 1200 O C. Four batches (50/50, 60/40, 70/30, 75/25) of granite to clay ratio were designed to investigate the effect of the granite/clay ratio on the phase composition and densification parameters. Mineralogical and chemical composition of the starting raw materials was evaluated using XRD and XRF, phase composition, densification parameters, and microstructure of the fired batches were studied. The densification parameters decrease as increasing granite ratio and decreasing of clay. For the effect of the temperature, the bulk density, porosity, and water absorption decrease with increasing of the firing temperature, in batch no 1 and 2. Batch no 3, bulk density and linear shrinkage decrease, while apparent porosity and water absorption increase. Batch no 4. Bulk density and linear shrinkage decrease, apparent porosity and water absorption slightly increase till 1180 o C and decrease at 1200 o C. XRD and SEM with EDAX confirm that quartz and mullite are only two phases were detected. Feldspar was totally replaced by alkaline granite in the formation of vitrified ceramic tile masses. Alkaline granite is better sintering behaviour it reduces the verification temperature and decreases the water absorption from 1140 to 1200 o C. In the production of ceramic tiles, whitener of the fired product is not a required parameter; the substitution of feldspar for alkaline granite can be more beneficial due to the relatively higher cost of feldspars.