National Repository of Grey Literature 7 records found  Search took 0.00 seconds. 
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...
Mineralogy of particulates from semi-arid soils polluted by mining and smelting and their transformation/re-mobilization during bushfires
Tuhý, Marek ; Ettler, Vojtěch (advisor) ; Kříbek, Bohdan (referee)
This thesis is focused on biomass-containing topsoils from a highly contaminated semi-arid area in the vicinity of mining and smelting operations in Tsumeb and Kombat in the northern Namibia. The highest concentrations of inorganic contaminants were found in samples from Tsumeb and attained the following values (mg/kg): As 1920, Cd 81, Cu 5840, Hg 7,66, Pb 4880, Sb 266, Zn 3310. X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and electron microprobe analysis (EPMA) have been used for determination of mineralogical composition of particulates adhering to surfaces of biomass and occurring in the heavy mineral fraction of topsoils. Quantitative partitioning of contaminants within individual mineral phases has been determined using autoSEM; contaminants were mainly bound in the slag glass (As: 16.7 %; Cu: 12.7 %; Pb: 26.2 %; Zn: 33.9 % of total concentration) and in metal(loid)-rich Fe-hydroxides (As: 14.4 %; Cu: 7.7 %; Pb: 21.6 %; Zn: 32.5 %). On biomass- rich topsoil samples, we have experimentally proved that bushfires can be responsible for transformation and re-mobilization of contaminants. Mercury is completely released at temperatures around 300 řC. In the same temperature range, also As anad Sb are released due to arsenolite (As2O3) thermal degradation. Cadmium is released...
Geochemistry and mineralogy of Cu-Co smelting slags from Luanshya, Zambian Copperbelt
Natherová, Vendula ; Ettler, Vojtěch (advisor) ; Kříbek, Bohdan (referee)
This diploma thesis focuses on bulk chemical and mineralogical compositions of modern slags from Cu metallurgy at the Luanshya site in the Zambian Copperbelt. The aim of this thesis was to describe the formation of these slags, distribution of trace elements and their leachability. Slag samples were characterized using a combination of analytical methods (optical microscopy, scanning electron microscopy, X-ray diffraction analysis, quantitative microanalysis, electron microprobe analysis and leaching test designed to assess the environmental risk . Slags are mainly composed of silicates (clinopyroxene and fayalite) and silicate glass. Less common are melilite, leucite and monticellite. Grains of quartz were occasionally found in the slag matrix and correspond to a non-melted gangue. Copper is bound in sulfides or forms small inclusions trapped within in the silicate matrix. The crystallization process was probably relatively fast as revealed by skeletal crystals of olivine and the presence of glass. Copper concentrations in slags range from 1321-95 300 mg/ kg, Co concentrations in slags range from 247-5990 mg/kg. The EN 12457-2 leaching test demonstrated that harmful elements are not substantially released into the environment.
Mineralogy of particulates from semi-arid soils polluted by mining and smelting and their transformation/re-mobilization during bushfires
Tuhý, Marek ; Ettler, Vojtěch (advisor) ; Kříbek, Bohdan (referee)
This thesis is focused on biomass-containing topsoils from a highly contaminated semi-arid area in the vicinity of mining and smelting operations in Tsumeb and Kombat in the northern Namibia. The highest concentrations of inorganic contaminants were found in samples from Tsumeb and attained the following values (mg/kg): As 1920, Cd 81, Cu 5840, Hg 7,66, Pb 4880, Sb 266, Zn 3310. X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and electron microprobe analysis (EPMA) have been used for determination of mineralogical composition of particulates adhering to surfaces of biomass and occurring in the heavy mineral fraction of topsoils. Quantitative partitioning of contaminants within individual mineral phases has been determined using autoSEM; contaminants were mainly bound in the slag glass (As: 16.7 %; Cu: 12.7 %; Pb: 26.2 %; Zn: 33.9 % of total concentration) and in metal(loid)-rich Fe-hydroxides (As: 14.4 %; Cu: 7.7 %; Pb: 21.6 %; Zn: 32.5 %). On biomass- rich topsoil samples, we have experimentally proved that bushfires can be responsible for transformation and re-mobilization of contaminants. Mercury is completely released at temperatures around 300 řC. In the same temperature range, also As anad Sb are released due to arsenolite (As2O3) thermal degradation. Cadmium is released...
Contamination of floodplain of the Ploucnice by heavy metals: relation to its architecture
Hošek, Michal ; Goliáš, Viktor (advisor) ; Kříbek, Bohdan (referee)
Summary: This thesis is focused on mapping of contaminants released into the environment probably due to uranium mining. These chemical contaminants are used to reconstruct the sedimentary processes. The aim of the thesis was both the geochemical assessment of the situation in the catchment area of the Ploucnice River in Boreček using the flood sediments from the research points as sedimentary archives pollution for last decades. With depth profiles, gamma wire log, XRF and enrichment factors (LEF), we have tried to perform chemostratigraphic correlation of the sediments. As target elements U, Ba, Zn and Ni were chosen, whose concentrations are related to the grain size of the sediment. Furthermore, the theory of secondary pollution is developed.
Contamination of foodplain of the Ploučnice river by heavy metals: relation to its architecture
Hošek, Michal ; Goliáš, Viktor (advisor) ; Kříbek, Bohdan (referee)
Summary: This thesis is focused on mapping of contaminants released into the environment probably due to uranium mining. These chemical contaminants are used to reconstruct the sedimentary processes. In the thesis we evaluate geochemical situation in the catchment area in the locality Borecek (part of the municipality Ralsko) using the overbank sediments as sedimentary archives of pollution during the last decades by elements U, Ba, Zn, Ni and 226 Ra. A map of aerial survey of gamma activity was used to select the area of interest, for more accurate localisation we used a surface gamma spectrometry. On Borecek we retrieved ten depth profiles of alluvial sediments (up to 230 cm) and one in Mimon, all samples were subjected to X-ray fluorescence spectral analysis (XRF), across the floodplain we performed gamma wire logs. For interpretations of floodplains architecture electrical resistivity tomography (ERT) was used and selected profiles were analysed for the activity of 226 Ra and 210 Pb. Interrelation of 226 Ra and Ba proved that radiobarite is the main source of the gamma activity. 210 Pb / 226 Ra ratio was used as sediment age indicator. With enrichment factor (LEF), we performed chemostratigraphic correlation of the sediments, for that the concentration of the target elements is corrected for varying...
Experimental investigation of copper smelter fly ash dissolution in a tropical soil
Petráňová, Veronika ; Ettler, Vojtěch (advisor) ; Kříbek, Bohdan (referee)
In a laboratory pot experiment we investigated a time-dependent release of contaminants from smelter dusts into the soil water and soil. In the experiment we used smelter dusts from two different Cu smelters located in Copperbelt in Zambia (Mufulira and Chambishi). Experimental bags with 0.5 g of dust were placed into pots with 200 g of uncontaminated tropical soil (oxisol) and studied in a time frame of 504 h. Pots were irrigated by deionised water and maintained at the 80 % water holding capacity (WHC). Ten samplings of pore water were performed using the Rhizon pore water samplers. In soil waters, the major released contaminants were Cu, Co and Zn. Concentrations of Cu and Co in soil waters C (from soil with the dust from Chambishi) and M (from soil with the dust from Mufulira) increased during first 48 and 216 h, while concentration of Zn reached highest value in soil waters C and M in 24 and 144 h. This trend has not been observed for Pb, which was released in small amounts and obviously bound to soil constituents. Together with metals, sulfates were highly released into soil waters and affected the speciation of metals (formation of sulfate complexes). Compared to mass loss of the dust from Chambishi with low value (8%), the mass loss of dust from Mufulira after pot experiment were...

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