Phase, magnetism and thermal conductivity of glass ceramics from iron ore tailings

CHEN Hao(陈浩)¹, WU Yi-wen(吴益文)², ZHANG Hong(张鸿)¹, LI Zhi-cheng(李志成)^{1, 3}

(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Inspection Center of Industrial Products and Raw Materials,
Shanghai Entry-Exit Inspection and Quarantine Bureau of China, Shanghai 200135, China;
3. State Key Laboratory of Powder Metallurgy (Central South University), Changsha 410083, China)

Abstract:In order to develop the applications of ore tailings, the glass ceramics were prepared by using a conventional melting-quenching-sintering process. The phase component, microstructures, magnetic properties and thermal conductivities of the prepared glass ceramics were investigated by using X-ray diffractometer, scanning electron microscopy, vibrating sample magnetometer and thermophysical properties tester, respectively. The results show that orthorhombic olivine-type phase and triclinic sunstone-type phase formed when the glass was annealed at 700 oC, the concentration of olivine-type and sunstone-type phases decreased, the spinel-type cubic phase occurred and the amount increased when the annealing temperatures increased. The magnetic properties from the cubic spinel ferrites were detected in the glass ceramics, and the related saturation magnetization increased with the annealing temperature increasing. The porous glass ceramics with magnetic property showed much lower thermal conductivity, compared with the non-magnetic porous glass-ceramic and the dense glass-ceramics.

Key words:iron ore tailing; glass ceramics; microstructure; magnetic properties; thermal conductivity