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Speciation of arsenic in a historical mine wastes
Knappová, Magdaléna ; Drahota, Petr (advisor) ; Jurkovič, Ľubomír (referee)
There are many locations with historical mining wastes around the world that contain high concentrations of pollutants and harmful elements. Mineralogical composition of those wastes has a major impact on release and later migration of dangerous elements into surrounding environments, resulting in potential environmental risk. Goal of this master thesis is to characterize mobility and major sinks of arsenic in 50-years-old mining waste materials at Jedová mine near Vejprty and Dlouhá Ves mine near Havlíčkův Brod. For this purpose, solid waste and pore water samples were collected from both mining waste dumps. Solid samples were analysed by mineralogical (XRF, XRD, SEM-WDS and Raman microspectroscopy) and geochemical (sequential extraction) methods, while pore water samples were analysed using IPC-MS (cations), HPLC (anions) and spectrophotometry (Fe3+/Fetot species). Arsenopyrite is the primary source of As at both localities. In the mining waste at Jedová jáma mine, As precipitates predominantly as amorphous ferric arsenate (HFA) and is also accumulated in scorodite and Fe (hydr)oxide (up to 3.2 wt.% of As2O5). In Dlouhá Ves, due to weathering of large amount of sulphides (sphalerite, chalcopyrite, galena, pyrite and pyrrhotite), acidic conditions prevail (pH ~ 2.7). Under this pH, the major part...
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