Recovery of Antimony from Refinery Slag of Unified Mining Company (EMUSA)

Abstract

The process of obtaining antimony trioxide from Unified Mining Company S.A. (EMUSA) has two production lines. The refining slag from the second production line was stored since the plant started operations, registering high antimony contents which is the reason for this research project. To recover antimony from the slag, it was necessary to carry out a reducing fusion with slag using pyrometallurgical methods with ternary diagrams; ${\text{FeO}}{:}{{\text{Na}}}_{2}{\text{O}}{:}{{\text{SiO}}}_{2}$ and ${\text{FeO}}{:}{{\text{SiO}}}_{2}{:}{\text{CaO}}$ the Sb recovery was done in two parts; the first part consisted of melting in a flame furnace and the second a melting in the IIMETMAT thermobalance. The flow of oxygen necessary for antimony recovery was 0.1 ${\text{l}}/{\text{min}}$ higher flows oxidize antimony and lower recovery. The experiments showed that the reaction that controls the process is ${{\text{PbSb}}}_{2}{{\text{O}}}_{6}+6{\text{C}}=2{\text{Sb}}+{\text{Pb}}+6{\text{CO}}$. For the melting in the flame furnace, the best slag ratio used was 35:15:50 with the system and with the system, the best ratio was 35:15:50, with Sb recoveries of 98% in both cases.