Stabilization of Free Lime in BOF Slag by Melting and Solidification in Air

The present study reports on the mineralogy of BOF slag after melting and solidification under Ar and air atmosphere. Results indicate that free lime can be effectively stabilized in air without additional stabilizers like SiO2. The stabilization mechanism was analyzed, and the role of the oxygen partial pressure was explored. Wustite is believed to be oxidized to hematite under high oxygen partial pressure and then stabilizes the free lime by forming brownmillerite.