Characterisation of Solid Mine Wastes Produced during Iron Ore Mining and Processing and their Potential Environmental Impacts

Abstract Solid waste deposited on the surface acts as a potential source of environmental pollution. High concentration of toxic elements in solid mine wastes can pose serious environmental risks. This study aims at characterising solid mine wastes produced due to iron ore mining and processing for their geochemistry and mineralogy. Samples were collected using a stratified sampling strategy. X-ray Fluorescence (XRF), X-ray Diffraction (XRD), and Petrographic analysis techniques were used. XRD analysis revealed a high abundance of Hematite (29%), with low amounts of Quartz stockpile samples. Berlinite (33%) amounts were high in waste dump samples, where Quartz was in high concentrations (34%) in the overburden samples. XRF analysis revealed a high amount of iron in the stockpile and waste dump, while Silica was highest in the overburden. Petrography analysis revealed major minerals in the solid mine waste: magnetite, Hematite, and Quartz with traces of mica, olivine, feldspar, and biotite. The minerals were characterised by a lamellar structure with mutual grain boundaries. Sulfide minerals that may cause acid drainage and various heavy metals were in considerable amounts. These elements have the potential of causing adverse environmental impacts hence the need for such characterisation to devise mitigation strategies and rehabilitation.