Insights into mineralogical characteristics of typical copper sulfide tailings using automated mineral liberation analysis: A case study from the Chambishi copper mine

As ore grades constantly decline, more copper tailings that still contain a considerable amount of unrecovered copper are expected to be produced as a byproduct of froth flotation. This research reveals the occurrence mechanism of copper minerals in a typical copper sulfide tailing using quantitative mineral liberation analysis (MLA) integrated with scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). The results show that copper minerals are highly disseminated within coarse gangue particles, and more than 90% of them are accumulated in the size fractions less than 106 μm. The predominant copper-bearing mineral is chalcopyrite, which is closely intergrown with orthoclase and muscovite rather than quartz. The flotation tailing sample still contains 3.28wt% liberated chalcopyrite and 3.13wt% liberated bornite because of their extremely fine granularity. The SEM-EDS analysis further demonstrate that copper minerals mainly occurred as fine dispersed and fully enclosed structures in gangue minerals. The information obtained from this research could offer useful references for recovering residual copper from flotation tailings.