The behavior of non-metallic inclusions during ladle refining

Key conclusions from the study include: 1. The inclusion removal rate followed first order reaction kinetics. Inclusion removal rate constants were found dependent on stirring power within the melt in proportion to ε ^0.28±0.08. The relationship had a high standard deviation, which may be a result of reoxidation occurring during refining and / or measurement uncertainties. 2. Elevated MgO concentration levels were found present in inclusions only after a state of slag-metal partial equilibrium had been established between slag and metal. Spinels were found less likely to form under highly oxidizing slags, but their formation was observed much more favourable below a (FeO + MnO) content of approximately 1wt%. 3. Results from this study suggest that ladle slag and possibly refractory are the key sources of magnesium contamination of steel. 4. Uncertainty in thermodynamic data for Al-Al2O3 and Ca-CaO equihbrium reactions was the key factor limiting the development of an inclusion model for potential use as an online control tool at ArcelorMittal Dofasco. 5. An approach comparing the CCSEM determined inclusion composition results to the total calcium and total oxygen contents in steel was found capable of providing a resonable approximation of oxide inclusion composition in the absence of microscopic examination.