ZrO ₂ –BaO co‐doping effects on Li ₂ O–Al ₂ O ₃ –SiO ₂ transparent glass‐ceramics from spodumene smelting slag

Abstract With the rapid development of the lithium battery and new energy industries, the large‐scale production of spodumene has led to the accumulation of significant amounts of spodumene smelting slag, causing environmental pollution and resource waste. In this study, a series of Li ₂ O–Al ₂ O ₃ –SiO ₂ (LAS) transparent glass‐ceramics were successfully prepared using 50 wt% spodumene smelting slag as the primary raw material. The effects of co‐doping with ZrO ₂ and BaO on the structure and properties of the glass‐ceramics were systematically investigated. Unlike most previous studies that focused on single‐component modification, this work highlights the novel co‐doping strategy of BaO and ZrO ₂ in a waste‐derived LAS system, and systematically investigates their synergistic and antagonistic effects on nucleation, crystallization, and properties. The optimal sample, treated at 600°C for 8 h for nucleation and 750°C for 2 h for crystallization, exhibited high crystallinity, a transmittance of 90.67% at 550 nm, a Vickers hardness of 7.07 GPa, and a relatively low coefficient of thermal expansion (CTE ≈ 8 × 10 ⁻⁶ K ⁻¹ ). Low ZrO ₂ content leads to insufficient nucleation, resulting in grain agglomeration and opacity, whereas excessive ZrO ₂ tends to act as a network former rather than a nucleating agent, thereby reducing the overall crystallinity. Partial substitution of SiO ₂ with BaO, functioning as a network modifier, induced local depolymerization of the glass network and effectively suppressed excessive grain growth, thereby maintaining high optical transparency. This work provides a promising route for the high‐value utilization of spodumene smelting slag and offers useful insights for designing high‐performance LAS transparent glass‐ceramics.