Removal of Antimony from Liquid Copper by Using CuCl–Na₂CO₃ Fluxes at 1423 K

Abstract

The removal rate of antimony from liquid copper by using CuCl–Na₂CO₃ fluxes was measured at 1423 K with argon gas atmosphere. The addition of Na₂CO₃ to CuCl flux was relatively effective for the removal of antimony. The concentration of antimony in liquid copper largely decreased with time or with increasing Na₂CO₃ content in flux. About 99.8% of antimony was removed from liquid copper during 15 min. The metal weight and oxygen content of metal increased with time and with increasing Na₂CO₃ content in flux. These behaviors were mainly due to the decomposition of Cu₂O formed in flux. The antimony in copper was oxidized.
According to the mass balance, about 60% of the removed antimony from liquid copper vaporized from the CuCl–23.8mass%Na₂CO₃ flux. The chlorination reaction between formed antimony oxide and CuCl might result in the vaporization of antimony from flux.
According to the above-mentioned experimental results, the CuCl–Na₂CO₃ fluxes were effective for the removal and recycling of antimony from liquid copper.