Fused Magnesia-Alumina Spinel (chemical formula: MgO·Al₂O₃) is a synthetic refractory material produced by melting industrial alumina and light-burned magnesia in tilting electric arc furnaces at ultra-high temperatures (≥2200°C). Characterized by an isometric crystal system (octahedral morphology) and high purity (MgO+Al₂O₃≥97%), it exhibits:  

- Exceptional thermal stability: Melting point 2135°C, low thermal expansion (α=8.9×10⁻⁶/℃), and superior thermal shock resistance;  

- High density & corrosion resistance: Bulk density ≥3.45 g/cm³, low open porosity (4–6%), and inertness to molten slag/alkalis;  

- Mechanical robustness: Mohs hardness 8, high compressive strength.  

Primary Applications:  

- Steelmaking: Ladle linings, sliding gates, purging plugs;  

- Cement kilns: Refractory linings for transition zones;  

- Monolithic refractories: Al₂O₃-MgO castables, SiC-C trough mixes.