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

Abstract

The dissolution behavior of Sn in CaO–CaF 2 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 pO2. It was found that Sn dissolves into the molten flux as (SnO 3)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 (LSn=(%Sn)flux/[%Sn]iron) was as low as ∼ 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. © 2021, The Minerals, Metals & Materials Society.