Liezl M. Jabile | Ephraim E. Ibarra
A red clay-based porous ceramic for water aeration diffuser application was produced from different compositions of Lama-Lama clay, Kapatagan diatomite, and rice hull ash. The formulations were based on the clay to silica ratio of 40/60, 45/55, 50/50, and 55/45. Low-cost additives like cornstarch and cassava starch were also added as pore formers at 15 weight percentage. Cylindrical and rectangular test pieces were made by slip casting that was fired at 1050oC and 1150oC. The solid casting of slip was done by heating in a microwave oven at 60oC and 80oC, respectively. Various tests were conducted on the fired specimens such as firing shrinkage, water absorption, apparent porosity, bulk density, specific gravity, modulus of rupture, and scanning electron microscopy. The best formulation appropriate for air diffuser was the sample with the composition of 55/45 clay to silica ratio without starch and was fired at 1050oC.