OXIDATION PROTECTION OF MgO-C MONOLITHIC REFRACTORIES WITH TAR-RESIN BINDER AND METAL ANTIOXIDANTS

A new generation of tar-resin bonded magnesia carbon products with high performance has been developed based on a newly developed binder system. The binder, characterised by high carbon yield after carbonisation, results in forming an extremely strong carbon bonding. Improved refractories are more economic and have lower cost and low toxicity. Tar-resin is used not only in shaped refractories, but also in monolithic refractories. Immersion experiments of MgO-C monolithic refractories in liquid steel at 1600 C showed the formation of a dense and continuous MgO rich layer, on the interface between refractory and steel, and the possible formation of inclusions as large clusters protruding from the refractory surface. The powder was heated up to 1400 C in air to remove carbon, and was subsequently formed into brick shape. Standard ASTM was used to determine the MOR, porosity and density. Antioxidant materials played an important role in improving the mechanical properties. 6 refs.