电熔再结合镁铬砖的精炼渣浸实验

Corrosion of Fused-Rebounded MgO-Cr_2O_3, Refractory by Secondary-Refining Slags

用试样旋转法在1600℃下实验研究了CaO－SiO2－Al2O3－MgO－CaF2（3％）型精炼渣组成对电熔再结合镁铬砖的侵蚀影响．结合渣浸试样的电镜分析，结果表明，随渣碱度（CaO／SiO2）的增大，试样的侵蚀增加；碱度大于1．8时，试样在冷却过程中粉化．由于尖晶石保护层的生成，渣中Al2O3含量的增加能沽少侵蚀．随渣中MgO含量的增加，试样的侵蚀减少，在此基础上，讨论了对提高镁铬砖炉衬有利的炉外精炼造渣制度．

Applying a specimen-rotation method and with the aid of electronic microscope analyses, the influence of the composition of typical secondary-refining slags of the CaO-SiO2- Al2O3-MgO-CaF2 (3% ) system on the corrosion of fused-rebounded magnesite chrome (MgO-Cr2O3) refiactory was experimentally studied. The corrosion increases with increasing slag basicity (CaO/SiO2), and specimen spalling at cooling occurs at higher basicity of 1.8 ~2.5. Increase of Al2O3 content in slag can greatly suppress the corrosion by forming a spinel protective layer on the surface of the specimen. The presence of more MgO in slng can also slow down the corrosion merely by lowering the driving force for the dissolution of MgO form refractory into slag. Based on experimertal results, the favorite slag-making course for furnace lining life was also discussed.