UTILIZATION OF LOCAL QUARRY WASTE AS RAW MATERIAL IN THE PRODUCTION OF INSULATING FIREBRICKS

Abstract

Quarry waste from Barangay Binaliw, Cebu City, Philippines, was evaluated for its potential to produce insulating firebricks. The raw material, containing quartz, anorthite, and chlorite, was first ground in a ball mill and then dried in an oven for 24 hours. After the drying process, the material was then passed through a mechanical sieve sized at 150 microns. The sieved particles were then mixed with water prior to being pressed in a metallic mold at 20 MPa by a hydraulic press. The green bricks produced were then dried again for 24 hours in a drying oven and then fired in a muffle furnace to final temperatures of 800 °C, 900 °C, 1000 °C, 1100 °C, 1200 °C, and 13000C at a heating rate of 50 °C/min. These temperatures were held for 2 hours after being reached by the furnace. XRD characterization of the fired samples revealed the final mineralogical composition of Quartz, Anorthite, and Maghemite. ASTM standardized tests were conducted to assess bulk density, porosity, shrinkage, and crushing strength. The results identified 1100°C as the optimal firing temperature, yielding bricks with a bulk density of 1.83 g/cm³, a porosity of 32.5%, and a crushing strength of 23.53 MPa. Thermal instability was observed at 1200°C, where there was spalling, and at 1300°C, the bricks completely melted. This study demonstrates the feasibility of converting quarry waste into high-performance insulating firebricks, contributing to sustainable construction practices and the circular economy by re-purposing an environmental pollutant into a valuable industrial material.