|
With the rapid development of high temperature industries, such as steel, metallurgy, building materials and chemical industry, as well as the national concern on the development and utilization of mineral resources and the demand for energy saving and emission reduction, research and development on lightweight high temperature material is becoming more and more important. In this experiment, spinel high temperature material was synthesized through solid state reaction, using magnesite, which is extremely aboundant in China, and different Al source ofα-Al2O3,γ-Al2O3, and Al（OH）3 as raw materials. The influences of Al source, sintering temperature and formula on the phase, microstructure, mechanical properties, volume stability and high temperature erosion-wear behavior of the synthesized material were studied at first. Then, lightweight spinel refractories were prepared with addition of pore former, and the impact of type of pore formers and the addition amount of that on the mechanical properties were investigated.The results showed that spinel high temperature material could be fabricated by solid state reaction at 1500℃, 1550℃, 1600℃, or 1650℃, separately, using magnesite and different Al source ofα-Al2O3,γ-Al2O3, and Al（OH）3 at one time as raw materials. Spinel and periclase were the main phases of the synthesized material with magnesite andα-Al2O3 as the raw material, the bulk density and bending strength of that material was 3.32g/cm3 and 69.03MPa, respectively. The material had the lowest permanent linear change rate of 0.11%, which showed that the volume stability was good. The high temperature erosion-wear resistance was also excellent as the erosion rate was 0.0062cm3/g at 1200℃. As for the lightweight spinel refractory, when 20wt% sawdust was used as the pore former, the bulk density and compressive strength of that was 0.83 g/cm3 and 2.24MPa, respectively. However, the bulk density and compressive strength of that was down to 0.46 g/cm3 and 0.91MPa, respectively, with additional 3wt% of polystyrene ball as pore former.
|