Utilization of lignite ash as raw materials for ceramic tile

Abstract

This study presents a ceramic tile preparation to effectively utilize lignite bottom ash as one of raw materials. Bottom ash in the mixtures was varied in the range of 40-50 wt%. The milled raw materials were pressed at the pressure of 30 MPa to form 2×4 inch ceramic tiles. The samples were dried and tested for modulus of rupture in order to observe their green strength. Then, the samples were fired at 1150-1200°C. The sintered samples were investigated in terms of modulus of rupture (MOR), water absorption (WA) and phase composition. Tiles are classified according to their water absorption and modulus of rupture into 3 groups by following Thai Industrial Standards of ceramics tiles (TIS 2508-2555). The suitable dry strength of tiles were made from lignite bottom ash 50 wt%, Mae Tan clay 40 wt% and Lampang clay 10 wt% were obtained at 110°C is 2.82 MPa. Tiles were classified to group 2 after firing at 1150°C (WA = 7.03%, MOR = 32.48 MPa) and 1175°C (WA = 6.22%, MOR = 34.21 MPa) and group 1 after firing at 1200°C (WA = 0.72%, MOR = 34.51 MPa). This formula can be applied to both floor tile and wall tile production.