8. Refractory for Secondary Refining of Steel

Modern steel ladle is used not merely to transport liquid steel from BOF to caster, but also to act as a reactor vessel where refining of steel takes place to reduce impurities, carbon, alloy addition and killing (Al, Si, bi-metal) of steel to reduce oxygen and other gasses; these comprehend the necessity and critical role of refractories. Substantial modification and development have been brought into the refractory quality to eliminate carbon (C) and oxygen pick up into steel from refractory lining for ladle furnace (LF) and CAS–OB processes. Thus, refractory design in steel ladles, energy saving issues, variation of thermal conductivity with respect to conventional graphite and nanocarbon, thermal stress assisted cracks and refractory failure are discussed. RH degasser is in limelight to produce ultra-low C and high-alloyed steel with an efficient productivity. Most suitable refractory practice has been suggested in consideration of slag–refractory interaction that eventually facilitate prolong ladle life and high-quality steel.