The preparation and property study of clay slip from sedimentation pond muddy clay of Mae Moh mine for ceramic production

Abstract

The aim of this study was to analyze the development of clay slip for trial ceramic production using mud from the settling pond at the Mae Moh mine in Lampang Province mixed with Lampang white clay in a ratio of 30% muddy clay and 70% Lampang white clay, using sodium silicate as the dispersing agent (0.2% by weight). The result of XRD analysis showed the muddy clay was composed of quartz, muscovite, and kaolinite and had a chemical composition of SiO₂ Al₂O₃, CaO, Fe₂O₃, K₂O, MgO, Na₂O, P₂O₅ and SO₃. After preparing the clay slip, slip tests were performed. The clay slip was found to have a specific gravity of 1.67 m/s², with a flow rate of 15 seconds per volume of 300 milliliters. Next it was molded into test pieces and fired at temperatures of 1100, 1200 and 1250 ^oC to test for fire resistance. It was found that the pieces showed fire resistance up to 1250 ^oC and had strength of 23.53 MPa. The pieces had a water absorption of 2.47% and shrinkage after burning of 10%. Then experiments were carried out to form a small cup product with patterns on the outside surface. After shaping, the biscuits were fired at 750 °C, followed by a clear glaze and fired again at 1250°C. The resulting product was found to have a smooth texture, light brown color, even surface, standard shape, and no distortions.