Particle-stabilized ceramic foams from blast furnace slag: Role of the slurry pH and sintering temperature in tailoring pore structure and properties

Water-quenched blast furnace slag (BFS), a by-product of the steel industry, is highly important for environmental protection and resource conservation through its recycling. This study used BFS as the primary raw material and sodium dodecyl sulfate as the foaming agent to fabricate ceramic foams using the particle-stabilized foam method. The effects of slurry pH and sintering temperature on the microstructure and properties of the ceramic foams were studied. The results showed that as the slurry pH increased, the pore size of the ceramic foams first increased and then decreased, and the compressive strength first decreased and then increased accordingly. With increasing sintering temperature, both the pore size and porosity of the ceramic foams gradually decreased, resulting in increased compressive strength and thermal conductivity. At a pH of 5 and a sintering temperature of 1100 °C, the ceramic foams exhibited optimal performance with a porosity of 75.6 %, compressive strength of 1.11 MPa, and thermal conductivity of 0.0548 W/(m·K). These properties suggest potential applications as thermal insulation materials in buildings. The findings provide valuable insights into the preparation and performance optimization of BFS-derived ceramic foams.