精炼钢包铝镁系耐火材料轻量化及其渣蚀行为研究

Lightweight Alumina-Magnesia Refractory for Refining Ladle and Its Slag Corrosion Behavior

耐火材料轻量化是其重要发展方向之一,研发合适的多孔骨料取代致密材料且确保服役安全与寿命是一条重要途径。大型工业炉工作衬处于高温苛刻环境,其渣蚀致损是关键,不仅与钢渣运动有关,也受材料微结构的影响,仅凭单一实验手段难以探明。以精炼钢包铝镁系耐火材料为对象,研制了性能指标参数优异的轻量微孔刚玉骨料及其轻量铝镁系耐火材料,无论是静态还是动态渣蚀实验,轻量铝镁系耐火材料均表现出不亚于普通铝镁系耐火材料的抗渣性能。同时,根据自制多孔骨料性能参数,采用随机骨料-基质二元结构模型描述耐火材料微结构差异,构建其渣蚀过程的温度、流动、反应等多场耦合数学模型,利用数值模拟方法,探索不同条件下精炼钢包轻量化耐火材料的渣蚀特性,明确了多孔骨料的关键参数及轻量化铝镁系耐火材料的抗渣蚀机理,可为设计和开发长寿轻量化耐火材料提供理论指导,能促进精炼钢包等高温窑炉的节能降耗。

The lightweight refractory with micro-porous aggregates is of importance for energy-saving and consumption reducing in high temperature industries, and the slag corrosion resistance is significantly concerning its service life. Large industrial furnace lining is in high temperature and harsh environment, its corrosion damage is related to not only steel slag movement, but also the microstrncture of materials, and is hard to ascertain by experiments only. Based on A12O2-MgO refractory for refining ladle, the lightweight microporous alumina aggregates and lightweight A12O3-MgO refractories with ex- cellent performance parameters have been developed, and they showed same slag resistance as the ordinary refractories in the static and dynamic corrosion experiments. Meanwhile, according to the properties of porous aggregates, a geometry model of random aggregate-matrix, in which aggregates and matrix were described with different microstrnctures based on porous medium theory, was adopted. And a model coupled with micro-CFD （ Computational Fluid Dynamics） , temperature and reaction was established to describe the slag corrosion process. The characteristics of the slag corrosion on the lightweight refractories were initially investigated by mathematical simulation, and the suitable microstructure parameters and corrosion resistance mechanism of lightweight A12O3-MgO refractories for ladle lining were discussed. The simulation results agree well with experiments, which means the above model is promising for slag corrosion modeling. The key target for lightweight refractories design is the average pore size, and the lightweight lining for refining ladle is feasible. It can provide a theoretical basis for design and the development of lightweight refractory materials, and promote the energy- saving of high-temperature furnaces.