关键词: 锂尾矿, 微晶发泡陶瓷, 氧化助剂, Fe₂O₃含量, 孔结构, 发泡行为

Abstract: In this study, formed glass-ceramics using lithium tailings as primary raw material and silicon carbide (SiC) as the high-temperature foaming agent were prepared. The influence of iron oxide (Fe₂O₃) as an oxidation aid on the sintering behavior, pore structure, and physical properties of the foamed glass-ceramics was systematically examined. High-temperature microscopy, XRD, SEM and other microscopic characterization methods were employed to elucidate the underlying mechanisms by which Fe₂O₃ modifies the properties of the formed glass-ceramics. The results demonstrate that the incorporation of Fe₂O₃ significantly alters the color of the foamed glass-ceramics and influences their high-temperature foaming capability, pore structure, and physical properties. Fe₂O₃ facilitates the oxidation decomposition of SiC during the high-temperature foaming stage by supplying active oxygen (O^2-), thereby improving the high-temperature foaming ability of green body. At an optimal Fe₂O₃ content of 4% (mass fraction), a well-structured lithium tailings formed glass-ceramics is synthesized at 1 180 ℃, which exhibits an average pore size of 0.95 mm, a bulk density of 0.29 g/cm³, and a compressive strength of 3.19 MPa. Furthermore, increasing the Fe₂O₃ content promotes the transformation of the primary crystalline phase from azurite to fine-grained spinel, accompanied by a reduction in pore size. However, excessive Fe₂O₃ content (>4%) leads to an elevated sintering temperature and diminishes foaming ability.

Key words: lithium tailings, foamed glass-ceramics, oxidation aid, Fe₂O₃ content, pore structure, foaming behavior