Effect of Kaolin-Alumina ratio on physical and structural properties of ceramic porcelain

Abstract

Ceramic porcelain was prepared by sintering process at temperature of 850 °C, using minerals such as kaolin (Al2H4O9Si2) and feldspar (Na2OAl2O3·6SiO2) as main raw materials with addition of alumina (Al2O3) and silica (SiO2). This study was focus on the effect of kaolin addition and alumina reduction on the physical and structural properties of ceramic porcelain. Fixed value of feldspar and silica which are 20 wt% and 10 wt% respectively was mixed with x wt% of kaolin and 70-x wt% of alumina (with x = 30, 35, 40, 45 and 50). The composition was then mixed and sintered at 850 °C for 4 hours. Characterization were done to observe the properties of ceramic porcelain samples through X-Ray diffraction (XRD), X-Ray fluorescence (XRF), density, water absorption and firing shrinkage. XRD results show that the amount of corundum as main phase has increased with the increasing amount of kaolin and decreasing amount of alumina. XRF results show the percentage of elements presence in the raw materials. Density of the samples show decreasing values from 2.85 g/cm3 to 2.49 g/cm3 with the increasing amount of kaolin-alumina ratio. Both water absorption and firing shrinkage results show increasing values with increasing amount of kaolin and decreasing amount of alumina. Result obtained shows strong evidence that proved the addition of kaolin and reduction of alumina give significant effect on the physical and structural properties of ceramic porcelain.