Physicochemical and ceramic properties of clay materials from Barangay Tikalaan and Barangay Libertad (Talakag, Bukidnon, Philippines) and their suitability for ceramic bodies

Clayey materials from two barangays in Talakag, Bukidnon, Philippines, were studied for potential ceramic stoneware products. Twelve site samples were collected and investigated through X-ray Fluorescence analysis to determine physical and firing properties at 1100°C. In terms of chemical oxide content, the studied clays are rich in SiO₂, Al₂O₃, TiO₂, and Fe₂O₃. Physiochemically, results show large particle size variations with medium to low plasticity. Particle size distribution reveals that the average particle size is lower than 425 microns. SiO₂ (24.62-46.54%) and Al₂O₃ (26.85% - 42.10%) are major chemical oxides, followed by TiO₂ (1.42% - 2.78%), Fe₂O₃ (0.531% - 25.46%), and alkali and alkali earth oxides in trace amounts. These results determine their behavior on firing at a specified temperature. The range of color was determined using a portable color meter and shows that a few specimens are predominantly from cream to light cream or are a white color after firing at 1100°C. The linear shrinkage values vary from 1.79% to 25.685, weight loss from 3.15% to 33.40%, and bulk density from 1.23 to 1.77 g/cm³. The water absorption ranges from 13 % to 40.15 % and the apparent porosity ranges from 37% to 62%. The evaluation of the studied clays based on their physicochemical and ceramic properties revealed that they are suitable for the manufacture of ceramic wares such as earthenware tiles and fired brick bodies.