This invention provides a method for extracting
bismuth from
bismuth-containing
oxygen pressure conversion leaching residue, belonging to the field of non-
ferrous metal metallurgical technology. In this invention, dilute
sulfuric acid is added as a leaching agent to
bismuth sulfide concentrate for mixing and
slurry preparation, while a surfactant is added to obtain a mixed
slurry.
Oxygen is then introduced to perform
oxygen pressure conversion leaching on the mixed
slurry, yielding bismuth-containing
oxygen pressure conversion leaching residue. This residue is then mixed with an alkaline solution for alkaline conversion and
solid-liquid separation, yielding a conversion solution and bismuth
oxide residue. Finally, the bismuth
oxide residue is mixed with an acidic solution for acidic bismuth extraction and
solid-liquid separation, yielding a bismuth-rich
leachate and bismuth extraction residue. This invention converts
bismuth sulfide into easily acid-soluble bismuth
oxide, increasing the flexibility of the hydrometallurgical
system selection for low-grade
bismuth sulfide concentrate and enabling selective extraction of bismuth at ambient
temperature and pressure. Compared to direct chlorination leaching of
bismuth sulfide concentrate, the bismuth-rich
leachate has a lower concentration of
impurity ions such as iron, requiring less purification and
impurity removal pressure.