THE RECYCLING OF SOIL CONTAMINATED WITH IRON RUST FOR FABRICATE CERAMIC TILES

Abstract

The purpose of this research is to study the chemical properties of soil contaminated with iron rush. The study aims to determine the optimal mixing ratios of iron rush-contaminated soil with other soil and raw materials used in high-temperature firing for the development of ceramic tiles. The chemical analysis revealed that iron (Fe) was the element present in the highest quantity, with a concentration of 282,715 mg/L (141,357.5 mg/kg of contaminated soil). The composition of the iron-contaminated soil includes aluminum oxide (Al₂O₃), iron oxide (Fe₂O₃), potassium oxide (K₂O), titanium dioxide (TiO₂), manganese dioxide (MnO₂), magnesium oxide (MgO), phosphorus pentoxide (P₂O₅), chloride (Cl), calcium oxide (CaO), chromium oxide (Cr₂O₃), nickel oxide (NiO), copper oxide (CuO), zinc oxide (ZnO), and sulfur trioxide (SO₃). Among these components, Fe₂O₃ was found to be the most abundant, ranging from 72.04% to 78.85 % by molecular weight and loss of ignition (L.O.I.) 14.655%. The average density of the soil 1,632.50 kg/m³, the average moisture content 6.72 %. These values indicate that the density of the soil is similar to that of normal soil, which typically falls within the range of 1,492 kg/m³. The color of the soil is reddish-brown, resembling fired bricks. After the soil was developed into ceramic tiles, the physical properties were evaluated. The highest shrinkage, at 8.97%, was observed in the P60 formula fired at a temperature of 1,100 °C. The color of the tiles after firing varied from dark brown to orange, depending on the mixing ratio of the iron-contaminated soil, which contributes to the red-brown color. Increasing the proportion of iron-contaminated soil resulted in decreased tile strength, while higher firing temperatures increased tile strength. The highest flexural strength value, at 77.07 kg/cm², was obtained from the P80 formula fired at 1,100 °C. The P80 tile formula exhibited water absorption of more than 10% and a modulus of rupture (MOR) of less than 7 N/m², meeting the industrial standards (TSIS 2508-2555).