Preparation of lightweight foam glass-ceramics from copper slag tailings: Secondary aluminum slag as pore-forming agent.

To address metallurgical waste residue pollution, this study utilized copper slag tailings (CST) and waste glass (WG) as primary raw materials, with secondary aluminum dross (SAD) as a pore-forming agent, to produce lightweight spontaneous foam glass-ceramics. The effects of raw material ratios, sintering temperature (1120–1160 °C), and sintering time (0–40 min) on foam glass-ceramics properties were investigated, elucidating the correlations between various properties. Under optimal preparation conditions (CST: WG: SAD = 7:11:2, sintered at 1150 °C for 20 min), the foam glass-ceramics exhibited a bulk density of 0.41 g/m³, compressive strength of 2.32 MPa, open porosity of 61.02 %, 2-h water absorption of 83.76 %, and mean pore size of 3.12 mm. The sintering process transformed raw materials into substances like diopside subsilic ferrian, which enhanced the strength of lightweight foam glass-ceramics. Harmful substances in the raw materials can be immobilized within the internal structure of foam glass-ceramics, ensuring excellent environmental safety. Additionally, comprehensive characterization was conducted on the foam glass-ceramics, elucidating their composition, structure, and pore-forming mechanisms. [ABSTRACT FROM AUTHOR]