Clean and efficient separation of Pb-Sb alloy by vacuum gasification - Fractional condensation

Abstract

The Lead (Pb) - Antimony (Sb) alloy derived from Jamesonite (Pb4FeSb6S14) using the "Roasting - Reduction Smelting" method is typically isolated through a separation method known as "High Temperature Ash Blowing - Low Temperature Ash Blowing - Electrolytic Refining". However, the "Low Temperature Ash Blowing" separation method encounters several challenges, including elevated production pressure of refined Pb, significant emissions of smoke and dust, and suboptimal separation efficiency. This study utilizes the "Vacuum Gasification - Fractional Condensation" method as an alternative to the "Low Temperature Ash Blowing" method. The experimental findings demonstrate that by implementing specific optimal experimental conditions, such as a condensation temperature range of 904–1054K, a vacuum degree of 5Pa, a gasification temperature of 1173K, a holding time of 7h, and a height-diameter ratio of 0.27, condensates with Sb content exceeding 99.5 wt% can be procured, resulting in a direct Sb yield of 33 %. The remaining residues, with an Sb content ranging from 14 to 15 wt%, serves as a valuable input for the "Electrolytic Refining" process. This utilization significantly alleviates the burden on refined Pb production during the "Electrolytic Refining" process. The treatment procedure does not require the utilization of chemical reagents, and it generates no wastewater or exhaust gas.