Investigating the effect of alumina content on physical properties and pore structure of spodumene tailings-derived foamed ceramics

Abstract

In this study, spodumene tailings (STs) were investigated as a primary raw material for preparing of foamed ceramics (ST-FCs). The effects of Al₂O₃ content on the physical properties and pore structure of the foamed ceramics were systematically investigated. Comprehensive analyses of phase composition, crystalline structure, and high-temperature foaming behavior were conducted to elucidate the influence mechanisms of Al₂O₃ content on the performance of ST-FCs. The results indicate that STs, composed mainly of albite, quartz, and minor muscovite, had a low sintering temperature of 1160 °C, making it an ideal candidate for foamed ceramic production. The Al₂O₃ content significantly influenced the physical properties and pore structure of ST-FCs, which effect was associated with the appearance of the crystals generated in samples during foaming process. Optimal results were achieved at 24.04 wt % Al₂O₃, where the ST-FCs prepared at 1140 °C demonstrated a bulk density of 0.405 g/cm³, compressive strength of 7.84 MPa, and favorable pore structure (average pore diameter of 0.173 mm and apparent porosity as low as 0.96 %). These findings strongly indicated that FCs with high performance could be successfully prepared from STs by optimizing the Al₂O₃ content, which not only mitigated the environmental impact of STs but also effectively reduced the production cost of FCs.