|
|
Arsenic speciation in mining wastes - case studies in systems dominated by ferric sulfoarsenates
Jelenová, Helena ; Drahota, Petr (advisor) ; Filippi, Michal (referee) ; Jurkovič, Ľubomír (referee)
The aim of the thesis is to study behavior and mineralogy of arsenic in mine wastes with high levels of FeIII and SVI . Three methodological studies are related to (i) identification and characterization of secondary arsenic phases using a Raman spectrometry, (ii) chemical fractionation of arsenic in mine waste materials as observed by optimized sequential extraction, (ii) and investigation of thermodynamic properties of zýkaite. The mineralogy and mobility of arsenic was studied in mine waste material of five dumps located at three sites (Kaňk near Kutná Hora, Jedová jáma near Vejprty, and Dlouhá Ves) and in stalactite samples from two abandoned underground mines (Plavno and Mikulov near Teplice). Mineralogical and geochemical characterization of samples included standard methods and techniques. Chemical composition of solid and liquid (pore water, leachates) samples was performed using a XRF, ICP OES, ICP MS, etc. X-ray diffraction, Raman spectrometry and electron microscope equipped with microanalysis were the most frequent techniques used for mineralogical characterization of the solids. The results showed that the speciation of arsenic in the solid phase significantly varied among the studied sites and was a function of total concentration as well as proportion of the major components of...
|
|
|
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...
|
|
|
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...
|
guest ::
