Abstract:
The ceramic tile industry is a dynamic sector whose technological innovation and market trends have drawn a complex picture of products and processes. This technological evolution has directly entailed with raw material formulations. The focus of this study is on the synthesis of ‒Wollastonite and utilized as reinforcement filler for clay ceramic tile. The ‒Wollastonite was synthesized by taking the raw limestone as a lime precursor and rice husk as a source of silica. The lime and silica powders were mixed with 1:1 w/w ratio and then calcined in an electric furnace at a temperature of 900 °C for 4 hours. Lime was produced by calcination of limestone at 950 ℃ for 5 hours. Silica was extracted from rice husk ash by using alkaline extraction followed by acid precipitation. A silica yield of 91.34% was achieved after calcination of rice husk in an electric furnace at 700ºC for 6 hours. The ceramic tiles were fabricated at different ratio of clay-AZ and ‒ wollastonite. It was prepared by solid slip casting method by addition of 5, 15 and 25 % of ‒wollastonite with a particle size of <63, 63-75 and 75-125µm at firing temperature of 950, 1000 and 1050°C. The results show that a minimum linear shrinkage of 1.25% and an ignition loss of 2.32% for ceramic tiles were recorded on 25% ratio of ‒wollastonite with a particle size of 125µm at firing temperature of 950°C. The ceramic tiles fabricated were exhibited the lowest water absorption of 1.35%, the maximum bulk density of 2.35 g/cm3 and compressive strength of 38.35MPa with 25% ratio of ‒wollastonite and a particle size of 63µm at firing temperature of 1050°C. Similarly, the maximum acid resistance of 99.985% (minimum weight loss (0.015%)) was found between 75-125µm particle size with 25% ratio of -Wollastonite and 950ºC firing temperature. These results are consistent with the international standard of ceramic tiles.