Study on performance and mechanism of foamed ceramics based on lead fuming furnace slag

This paper proposes a new method for preparing lightweight and thermally insulated foamed ceramics via direct high-temperature foaming using lead fuming furnace slag as the major material, quartz sand as the texturizer, borax as the flux, and AlN as the foaming agent. The effects of the chemical composition and sintering process parameters on the crystalline phase transformation, pore structure, and properties of the foamed ceramics were investigated. The foaming mechanism during sintering was also examined using TG-DSC analysis and pore morphology analyses. These results indicate that the slag content strongly affects the formation of the pore structure. Different sintering parameters can modify the pore structure, and a single crystalline phase (CaSiO3) was generated during the sintering process. Under the optimum conditions, the foamed ceramics showed the best overall performance with the bulk density, apparent porosity, average pore size, thermal conductivity, and compressive strength of 0.221 g cm−3, 84.53 %, 1.10 mm, 0.1100 W/(m·K), and 2.52 MPa, respectively. Its excellent porous structure and low thermal conductivity make it suitable as a thermal insulation material in building partition walls.