Mechanisms of Oxidation and Vaporization of Antimony from Liquid Copper with CuCl–CaO Fluxes

Abstract

In order to clarify the reaction mechanisms of oxidation and vaporization of Sb in liquid copper by using CuCl–CaO fluxes, the vaporization behavior from CuCl–Sb₂O₃ and CuCl–CaO–Sb₂O₃ fluxes and the reaction behavior of Cu₂O between CuCl–Cu₂O flux and liquid copper were observed at 1423 K with argon gas.
For the vaporization from CuCl–Sb₂O₃ and CuCl–CaO–Sb₂O₃ fluxes, SbCl₃ and SbOCl in flux were observed in the fluxes, and these chloride and oxychloride vaporized to gas phase.
In the reaction between CuCl–Cu₂O and liquid copper, the decomposition of Cu₂O in the flux was confirmed, and the copper weight and oxygen content of copper increased.
The mechanisms of oxidation and vaporization of antimony in liquid copper by using CuCl–CaO fluxes were discussed based on the observed results. The Cu₂O existing in CuCl–CaO flux is dissolved in copper melt, and the oxygen content of copper increases. The antimony in liquid copper is oxidized and removed to slag phase as Sb³⁺. The formed Sb³⁺ in flux vaporizes from flux as SbCl₃ and SbOCl.