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Mineralogy and bioaccessibility of contaminants in wastes from mining and processing of Cu-Ni ores from Selebi-Phikwe (Botswana)
Hladíková, Karolína ; Ettler, Vojtěch (advisor) ; Kříbek, Bohdan (referee)
Mining, processing, and metallurgy of Cu-Ni ore in Selebi-Phikwe, Botswana, resulted in a large amount of solid waste material in the form of overburden, slag dumps, tailings, and smelter emissions. Fine particles could spread by wind and contaminate nearby soils or pose a risk for human health by inhalation or unintentional ingestion. Samples of granulated slag, flotation tailings, and contaminated soil were subjected to a multi-method mineralogical and geochemical analysis (ICP-MS, XRD analysis, EPMA, SEM, Raman spectrometry) to identify the distribution and binding of inorganic contaminants. Especially, the fine dust fractions <48 μm and < 10 μm, which could potentially pose a risk through ingestion or inhalation, were studied. Trace elements analysis indicated that slag is enriched in Cr (up to 499 mg/kg), Co (up to 857 mg/kg), Cu (up to 9600 mg/kg), Ni (up to 7000 mg/kg) and Zn (up to 690 mg/kg). Flotation tailings contain relatively high concentrations of Ni (up to 3000 mg/kg) and contaminated soil is especially enriched in As (up to 53,8 mg/kg), Cd (up to 28 mg/kg), Cu (up to 3810 mg/kg), Ni (up to 2790 mg/kg) and Pb (up to 181 mg/kg). The finer dust fraction <10 μm is generally more metal(loid)-rich than the <48 μm fraction. The main contaminant hosting phases in all the studied samples are...
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Magnetic fabric of detrital sediments as a record of depositional processes and tectonic deformation
Hladíková, Karolína ; Martínek, Karel (advisor) ; Kadlec, Jaroslav (referee)
Fabric of sedimentary rocks can be studied by the analysis of magnetic properties, especially by magnetic anisotropy. Anisotropy of magnetic susceptibility (AMS) is a relatively easy and quick method capable to recognize the rock fabric (primary or secondary). The results of AMS are strongly dependent on magnetic properties of rock- forming minerals and their preferred orientation. The preferred orientation of grains develops by sedimentation, post-depositional diagenetic processes and eventually by tectonic deformation, which can totally overprint the primary structure in some cases. I applied AMS to study the magnetic fabric of fine-grained lacustrine sedimentary rocks from 9 different beds of Vrchlabí section, situated in the northern part of the Krkonoše Piedmont Basin. Paramagnetic minerals dominate the magnetic susceptibility, with possible small amount of ferromagnetic phases of some iron oxides. Most of the samples are laminated mudstones and they have depositional magnetic fabric carried by flat grains of clay minerals deposited horizontally from suspension. Carbonate bed shows signs of inverse magnetic fabric, which is in accordance to magnetocrystalline anisotropy of calcite. Magnetic fabric of early tectonic overprint, probably present in some black shale and siltstone beds, may be...
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