Surface modification mechanism of galena with H2SO4 and its effect on flotation separation performance

The development of galena flotation inhibitors is a key focus and challenge in the flotation of polymetallic sulfide ores. In this paper, H2SO4 was used to modify the galena surface and to reduce its surface hydrophobicity, and the modification mechanism of the galena surface was studied through microflotation experiments, contact angle determination and X-ray photoelectron spectroscopy (XPS). The microflotation results showed that the galena floatability after modification with H2SO4 decreased significantly, and the main influencing factors were sulfuric acid concentration, modification temperature and time. The surface contact angle of galena decreased from 93.03 degrees to 44.67 degrees under optimum modification conditions. The XPS analysis results indicated that hydrophilic PbSO4 species were produced on the galena (PbS) surface. The modification-flotation experiment results of the galena-chalcopyrite mixture indicated that efficient separation performance between the two minerals was obtained, which was consistent with the contact angle and XPS analysis described above. This new method provides a potential application for the flotation separation of galena-containing polymetallic sulfide ores.