Study Properties Of Periclase-magnesia Alumina Spinel Refractories Used For RH Snorkel

At present in the outside of the furnace refining process mainly depend on RH vacuum refining furnace, and obtained the violent development, RH furnace lining refractory material is widely used. RH furnace lining still use magnesia chrome bricks, magnesia chrome refractory has high temperature and excellent performance, which has been widely used. However, the materials containing Cr2O3, they produce Cr6+ in the process of high temperature. Cr6+ has a serious carcinogenic, and soluble in water, causing serious environmental problems. With the increasing development of refining and environmental requirements, RH furnace performance materials are needed to replace magnesite-chrome brick.Based on the review of the literature and on the basis of the current study chromium-free RH furnace applications, using fused magnesia and sintered spinel as the main raw material, adding tabular alumina, titanium dioxide, zirconium silicon to fabricate periclase- spinel brick. Studying spinel granularity, amount, type of spinel and tabular alumina, adding TiO2 and ZrO2 materials’ impact to properties. By using XRD, SEM, EDS and other equipment and tools on the microstructure and properties of the material for analysis. The results show that: the purpose of spinel introduced in the form of mesh 200 periclase- spinel brick has the best performance; spinel addition is 15% has the best performance; 66 sintered spinel and tabular alumina compound has the best performance; with the amount of TiO2 increasing, the volume density of the material increases, porosity reduces, room temperature and high temperature strength increase, slag resistance enhancemens, TiO2 addition is 2% has the best thermal shock resistance; adding 4% ZrO2 bulk density material is largest and apparent porosity is the lowest, adding 3% ZrO2 material has room temperature flexural and compressive maximum strength, while adding 4% ZrO2 temperature has flexural maximum strength, adding 3% ZrO2 thermal shock resistance is the best, adding ZrO2 can improve the material resistance to slag erosion and permeability; 2% TiO2 and 1% ZrO2 sintering is the best, the greatest compressive strength at room temperature;2% of TiO2 and 2% ZrO2 has the maximum bending strength at room temperature; adding 1% of TiO2 and 2% ZrO2 the thermal shock resistance is best, adding 2% of TiO2 and 1% ZrO2 has the largest high temperature flexural strength, adding 2 % TiO2 and 2% ZrO2 has the best resistance to slag erosion and permeability.