Crystallization Characteristics and Properties of Glass Ceramics Derived from Iron Tailing

In this study, iron tailings were used as raw materials mixing with Al2O3, SiO2, and/or CaO sintered at 950–1400 °C to produce glass ceramics. In Al2O3/tailing and Al2O3/SiO2/tailing systems, the newly formed crystalline mullite (3Al2O3·2SiO2) reached its maximum content of 83.7 wt% for sample with Al2O3/SiO2/tailing mass ratio of 6/2/2. In Al2O3/SiO2/CaO/tailing system, the content of newly formed anorthite (CaAl2Si2O8) increased to the maximum of 72.9 wt% for sample with Al2O3/SiO2/CaO/tailing mass ratio of 7/8/4/6 sintered at 1450 °C. The properties of glass ceramic products were significantly improved in samples with high content of crystalline mullite or anorthite and low surface porosity. Obtained glass ceramic in Al2O3/SiO2/tailing system with mass ratio of 6/2/6 showed excellent properties of chemical resistance (99.99%), compressive strength (1061.6 MPa), and low water absorption (0.2%). The high performance of glass ceramics and low leachability of hazardous metals shed light on the potential application of iron tailings in building and decorative materials.