Red mud/silica sand tailing-derived glasses and glass-ceramics for architectural decoration: crystallization, structure, properties and immobilization of heavy metals

• Published in: Construction & building materials 2023-10, Vol.400, p.132873, Article 132873
• Main Authors: Liu, Jianlei, Yu, Zhumei, Zheng, Jie, Peng, Huanan, Zhang, Zhou, Ye, Hongde, Peng, Siyan, Lin, Xinmei, Duan, Wenjiu, Wang, Qikun
• Format: Article
• Language: English
• Subjects: Glass-ceramics; Glasses; Heavy metals; Red mud; Silica sand tailing
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2023.132873

[Display omitted] •The red mud (RM) and silica sand tailing (SST) were combined to prepare solid waste-derived glasses and glass-ceramics.•The work realized a maximum utilization rate of RM and SST without additive.•The GCRS6/4 shows the best properties and high immobilization efficiencies of heavy metals. To achieve high-efficiency utilization of red mud (RM) and silica sand tailing (SST), this work used them to prepare glasses and glass-ceramics with different mass ratios of RM/SST. The crystallization kinetics, crystal evolution, structure, properties, and the immobilization of heavy metals were studied. The results show that the parent glasses’ activation energies for crystallization are in the range of 371.77–414.03 kJ/mol, and the crystallization mechanisms should be the bulk crystallization or the combination of surface and bulk crystallization. With the increase of SST content, the main crystal phase in the glass-ceramics will change from NaAlSiO4 to (Ca,Na)(Si,Al)4O8, which further results in the variations of structure and properties. By comparison, it is found that the glass–ceramic GCRS6/4 shows the best properties, including low density and water absorption, high bending strength, excellent acid and alkali-resistance. In addition, the GCRS6/4 also shows high immobilization efficiencies for heavy metals including Fe3+, Cu2+, Zn2+, Pb2+ and Cr3+ ions. This investigation not only achieved the high-efficiency utilization of RM and SST, but also produced a novel eco-friendly glass–ceramic material for architectural decoration.