Improved understanding of the sulfidization mechanism in cerussite flotation: An XPS, ToF-SIMS and FESEM investigation

Abstract

Sulfidization can greatly improve the flotation performance of lead oxide minerals. To provide deeper knowledge about this process, sulfidization of cerussite was investigated using X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and field emission electron microscopy (FESEM). XPS results clearly indicated a transformation of PbCO3 into PbS on the cerussite surfaces during sulfidization, which was consistent with ToF-SIMS results. Further, FESEM images showed that many nanoparticles grew on the cerussite at a high density, suggesting that the sulfidization product on the cerussite was not a monatomic layer but a solid polyatomic layer. The above results confirmed that PbS nanoparticles could grow on most of the surfaces of cerussite under flotation-related conditions, indicating that the sulfidized cerussite had a PbCO3/PbS core-shell structure. The formation of PbS nanoparticles on cerussite involved a heterogeneous nucleation step followed by growth of the nuclei. Based on these studies, a sulfidization process model was finally obtained.