Enhanced elemental and mineralogical imaging of Cu-mineralized rocks by coupling μ-LIBS and HSI

Abstract

The decarbonization of energy sources and electromobility depend on the efficient production of Cu-based materials. A fast and detailed instrumental analysis of mineral species in copper rocks is a need in the modern mining industry, but it remains as an analytical challenge. In this paper we address a detailed mineralogical characterization by the combination of micro laser-induced breakdown spectroscopy (μ-LIBS)-based imaging and hyperspectral imaging (HSI), in three different Cu-mineralized rocks. Based on the complementary information obtained by μ-LIBS and HSI we characterized the distribution of valuables species such as chalcopyrite (CuFeS₂), bornite (Cu₅FeS₄), chalcocite (Cu₂S), covellite (CuS), enargite (Cu₃AsS₄), magnetite (Fe₃O₄), and barren minerals like calcite (CaO), anhydrite (CaSO₄), quartz (SiO₂), alunite (KAl₃(SO₄)₂(OH)₆) and pyrophyllite (Al₂Si₄O₁₀(OH)₂). The results demonstrate that the elemental and mineralogical characterization of Cu-mineralized rocks can be carried out by the complementary use of both techniques and simple chemometric methods. These results are an important step towards a fully automated mineral characterization of Cu-bearing rocks at a sample scale.