HOU Qingdong ¹, LUO Xudong ¹, XIE Zhipeng ², AN Di ²

(1. School of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan 114051, Liaoning, China; 2. State Key Lab of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China)

Abstract: Mg₂SiO₄ precursor made through the coprecipitation method was used as a binder to prepare fused MgO refractories, in order to improve their comprehensive properties. Thermal properties, phase composition and microstructure of the Mg₂SiO₄ precursor were characterized by using DSC-TG, XRD and SEM. The effect of the Mg₂SiO₄ precursor on sintering properties and thermal shock resistance of the fused MgO refractories was studied. It was found that the precursor was completely converted to forsterite after sintering at 1000 °C, while the grains were well developed. With increasing content of Mg₂SiO₄ precursor, the bulk density, linear shrinkage and cold crushing strength of the samples sintered at 1550 °C were firstly increased and then decreased. The sample with 2wt.% Mg₂SiO₄ exhibited the highest bulk density and cold crushing strength, which were 3.18 g·cm^-3 and 243 MPa, respectively. The synergistic effect of the forsterite and periclase particles enabled high thermal shock resistance of the samples, because the Mg₂SiO₄ precursor was bonded with the fused MgO refractories, with water-cooling cycles of up to 15 times.
Key words: forsterite precursor; coprecipitation method; fused magnesia refractory; sintering property; thermal shock resistance