Fabrication of lightweight clay-based refractory bricks using recycled EPS polymer

In this study, a low-cost and eco-friendly process was employed to fabricate lightweight refractory bricks. The porous bricks were produced using high-alumina clay and recycled expanded polystyrene (EPS) as pore-forming agents. To improve plasticity, the clay formulation was modified through the incorporation of 10 wt% montmorillonite. The lubricant and water contents were optimized to 0.07 wt% and 26.3 wt%, respectively. The prepared plastic clay, containing varying amounts of waste EPS particles (40, 50, and 60 vol%), was molded and sintered at 1200 °C. Microstructure study confirmed the formation of mullite phase from the decomposed products of kaolinite. The porosity of the bricks enhanced from 35 % to 54 % and average pore size increased from 1430 to 1740 μm as the EPS content increased from 40 to 60 vol%, while the compressive strength declined from 4.8 to 2.5 MPa, respectively. The relationship between strength and porosity exhibited a strong correlation with the power-law equation of Ryshkewitch-Duckworth. • Lightweight refractory bricks was fabricated using high-alumina clay and recycled EPS. • Incorporation of different amounts (40–60 vol%) EPS into plastic clay was studied. • Mullite phase formed from kaolinite decomposition at 1200 °C. • With enhancing the porosity from 35 % to 54 % strength changed from 4.8 to 2.5 MPa. • Pore size increased from 1430 to 1740 μm according to EPS content increasing from 40 to 60 vol%.