Dissolution Behavior of Sn in CaO-CaF2 Molten Flux and Its Distribution Ratio Between CaO-CaF2 Molten Flux and Liquid Iron

The dissolution behavior of Sn in CaO-CaF2 flux was investigated. A chemical equilibration technique was employed which allows pure liquid Sn dissolves into the molten flux under various oxygen partial pressure and the flux composition. At an equilibrium, (% Sn) in the flux increased by increasing (% CaO) and p(O2). It was found that Sn dissolves into the molten flux as (SnO3)(4-) in the condition of the present study. Distribution of Sn between CaO saturated flux and C saturated liquid Fe was measured under a pure CO atmosphere. Sn distribution ratio (L-Sn = (%Sn)(flux)= [%Sn](iron)) was as low as similar to 10(-4), which was consistent with a thermodynamic prediction. Sn distribution was favored at a lower temperature. Thermodynamic modeling was carried out for the Sn dissolution in the flux. A noticeable negative deviation between CaO and SnO was identified.