Zugl.: Karlsruhe, Universiẗat, Diss., 1992.

Zugl.: Cottbus, Techn. Universiẗat, Diss., 1999.

Zugl.: Bayreuth, Universiẗat, Diss., 1997.

Freshwater shortages causes challenges in mineral processing in Chile, especially in arid regions. As a result, froth flotation; a mineral process, is shifting usage of freshwater to seawater. This has consequences in the consumption of flotation reagents and decreasing the flotation efficiency. Biotechnological developments allow conceptualising the use of bacterial cells and their metabolites as bioreagents in flotation; classified as bioflotation. In this thesis, 5 halophilic bacteria, namely, Halomonas boliviensis, Marinobacter spp., Halobacillus litoralis Hol-1, Marinococcus halophilus KOR-3 and Halomonas eurihalina P6-1 have been screened for the potential use as pyrite biodepressants at micro- and batch-scale flotation. The effect of bioconditioning minerals with these bacteria was studied using zeta potential, fluorescence microscopy and contact angle. Experiments measuring zeta potential show the isoelectric point (IEP) of pyrite, chalcopyrite and molybdenite became more acidic post-bioconditioning. Fluorescence microscopy with Nile red; a hydrophobic stain, allowed for a method to visualize bacterial cells or collector potassium isopropyl xanthate (KIPX) on mineral particles of pyrite, chalcopyrite and molybdenite. Additionally contact angle experiments show that strains Halobacillus litoralis Hol-1, Marinococcus halophilus KOR-3 and Halomonas eurihalina P6-1 had an influence on the contact angle of pyrite and chalcopyrite, inducing changes in their hydrophobicity. Microflotation experiments showed a decreased recovery of pyrite in presence of all strains, but notably, Halobacillus litoralis Hol-1 and Marinococcus halophilus KOR-3, also showed an increased recovery of chalcopyrite, making them ideal candidates as pyrite biodepressants. Halomonas eurihalina P6-1 showed low recoveries of both minerals, but a higher selectivity depressing more pyrite than chalcopyrite. Usage of autoclaved biomass from the three aforementioned strains in batch-flotation experiments resulted in the recovery of chalcopyrite improving, with a small decrease in the recovery of pyrite, overall showing a positive potential but not improving the system. Halophilic bacteria such as the ones used in this study show an influence on the floatability of pyrite, which could be commercially exploited to substitute lime as a pyrite depressant. Furthermore, the work in this thesis focused on studying the effects of cells in artificial seawater, both at micro and batch-scales which brings the laboratory experiments a step closer to industrially relevant conditions.

The neoidic sulphide mineralization located in tertiary sediments of Lom Bílina in Bílina's fault is of hydrothermal origin. The sulphidic mineralization is associated with fault systems of Eger rift and temperature of fluid crystallization was about 50řC. The mineralization of Bílina's fault is rather monotonous, the marcasite and pyrite is mostly found without a trace elements. In the crystals were also registered zones with the contents of trace elements, especially As and Ni. The contents of As enriched precipitation zones were fluctuating from 0,2 to 5,4 wt. %, Ni enriched zones were ranged from 1,6 to 5,9 wt. %. The precipitation zones with increased As and Ni content were very thin, there were very short time intervals of As and Ni enriched fluids precipitation. In the marcasite crystals were also found the porous zones of clay mineral microinclusions. These zones showed higher content of Al and Si. There is high abundance of Fe-disulfides at Bílina's fault-dispersed in coal bed, or bonded to tectonic zone of the Bílina's fault. Pyrite and marcasite are dispersed in the coal bed and genetially aren't related to sulphides bonded to Bílina's fault.

<p>Chemical stabilization of mine waste from Ljusnarsbergsfältet with sewage sludge and calcium carbonate residues</p><p>Mine waste from Ljusnarsbergsfältet in Kopparberg, Sweden, is considered to constitute a great risk for human health and the surrounding environment. Some of the waste rock consists of sulphide minerals. When sulphide minerals come into contact with dissolved</p><p>oxygen and precipitation, oxidation may occur resulting in acid mine drainage (AMD) and the release of heavy metals. The purpose of this study has been to characterise the waste material and try to chemically stabilize the waste rock with a mixture of sewage sludge and calcium carbonate. The drawback of using organic matter is the risk that dissolved organic matter can act as complexing agents for heavy metals and in this way increase their mobility. An additional study to examine this risk has therefore also been performed.</p><p>The project started with a pilot study in order to identify the material fraction that was suitable for the experiment. When suitable material had been chosen, a column test was carried out for the purpose of studying the slurry’s influence on the mobility of metals along with the production of acidity. To clarify the organic material’s potential for</p><p>complexation a pH-stat batch test was used. Drainage water samples, from the columns,</p><p>were regularly taken during the experiment. These samples were analyzed for pH, electrical conductivity, alkalinity, redox potential, dissolved organic carbon (DOC), sulphate and leaching metals. The effluent from the pH-stat-test was only analyzed on a few occasions and only for metal content and change in DOC concentration.</p><p>The results from the laboratory experiments showed that the waste rock from Ljusnarsberg easily leached large amounts of metals. The stabilization of the waste rock succeeded in maintaining a near neutral pH in the rock waste leachate, compared to a pH 3 leachate from untreated rock waste The average concentration of copper and zinc in the leachate from untreated waste rock exceeded 100 and 1000 mg/l respectively, while these metals were detected at concentrations around 0.1 and 1 mg/l, respectively, in the leachate from the treated wastes. Examined metals had concentrations between 40 to 4000 times lower in the leachate from treated waste rock, which implies that the stabilization with reactive amendments succeeded. The long term effects are, however, not determined. The added sludge contributed to immobilize metals at neutral pH despite a small increase in DOC concentration. The problem with adding sludge is that if pH decreases with time there is a risk of increased metal leaching.</p>

Die Arbeit entwickelt eine Methodik zur Gefährdungsprognose der Kippenumgegend durch stark mineralisierte, saure Kippengrundwässer. Für die Standorte Espenhain und Jänschwalde wurden Feld- und Laboruntersuchungen sowie Simulationen zur Wiederaufsättigung und zum reaktiven Stofftransport durchgeführt. Die geochemische Vorfeldbilanzierung ist ein wesentliches Werkzeug zum Verständnis der sich entwickelnden Kippenwasserbeschaffenheiten. Die Felduntersuchungen auf der Kippe Espenhain zeigen im Liegenden der Verwitterungszonen den Ablauf reduktiver Prozesse, verkoppelt mit der Umsetzung tertiärer organischer Substanz. Deren lokal nachgewiesene Abfolge bis zur Sulfatreduktion ist ein nachhaltiger Selbsthilfemechanismus bezüglich der durch Verwitterung freigesetzten Acidität und Metalle. Die weitere Untersuchung der Redoxsequenz und ihrer technischen Beeinflussbarkeit ist geboten. Innerhalb der Arbeit wird das reaktive Stofftransportprogramm PCGEOFIM verifiziert und für beide Standorte angewendet.

Chemical stabilization of mine waste from Ljusnarsbergsfältet with sewage sludge and calcium carbonate residues Mine waste from Ljusnarsbergsfältet in Kopparberg, Sweden, is considered to constitute a great risk for human health and the surrounding environment. Some of the waste rock consists of sulphide minerals. When sulphide minerals come into contact with dissolved oxygen and precipitation, oxidation may occur resulting in acid mine drainage (AMD) and the release of heavy metals. The purpose of this study has been to characterise the waste material and try to chemically stabilize the waste rock with a mixture of sewage sludge and calcium carbonate. The drawback of using organic matter is the risk that dissolved organic matter can act as complexing agents for heavy metals and in this way increase their mobility. An additional study to examine this risk has therefore also been performed. The project started with a pilot study in order to identify the material fraction that was suitable for the experiment. When suitable material had been chosen, a column test was carried out for the purpose of studying the slurry’s influence on the mobility of metals along with the production of acidity. To clarify the organic material’s potential for complexation a pH-stat batch test was used. Drainage water samples, from the columns, were regularly taken during the experiment. These samples were analyzed for pH, electrical conductivity, alkalinity, redox potential, dissolved organic carbon (DOC), sulphate and leaching metals. The effluent from the pH-stat-test was only analyzed on a few occasions and only for metal content and change in DOC concentration. The results from the laboratory experiments showed that the waste rock from Ljusnarsberg easily leached large amounts of metals. The stabilization of the waste rock succeeded in maintaining a near neutral pH in the rock waste leachate, compared to a pH 3 leachate from untreated rock waste The average concentration of copper and zinc in the leachate from untreated waste rock exceeded 100 and 1000 mg/l respectively, while these metals were detected at concentrations around 0.1 and 1 mg/l, respectively, in the leachate from the treated wastes. Examined metals had concentrations between 40 to 4000 times lower in the leachate from treated waste rock, which implies that the stabilization with reactive amendments succeeded. The long term effects are, however, not determined. The added sludge contributed to immobilize metals at neutral pH despite a small increase in DOC concentration. The problem with adding sludge is that if pH decreases with time there is a risk of increased metal leaching.

Die Arbeit entwickelt eine Methodik zur Gefährdungsprognose der Kippenumgegend durch stark mineralisierte, saure Kippengrundwässer. Für die Standorte Espenhain und Jänschwalde wurden Feld- und Laboruntersuchungen sowie Simulationen zur Wiederaufsättigung und zum reaktiven Stofftransport durchgeführt. Die geochemische Vorfeldbilanzierung ist ein wesentliches Werkzeug zum Verständnis der sich entwickelnden Kippenwasserbeschaffenheiten. Die Felduntersuchungen auf der Kippe Espenhain zeigen im Liegenden der Verwitterungszonen den Ablauf reduktiver Prozesse, verkoppelt mit der Umsetzung tertiärer organischer Substanz. Deren lokal nachgewiesene Abfolge bis zur Sulfatreduktion ist ein nachhaltiger Selbsthilfemechanismus bezüglich der durch Verwitterung freigesetzten Acidität und Metalle. Die weitere Untersuchung der Redoxsequenz und ihrer technischen Beeinflussbarkeit ist geboten. Innerhalb der Arbeit wird das reaktive Stofftransportprogramm PCGEOFIM verifiziert und für beide Standorte angewendet.

Jämtlands berggrund består till stora delar av sedimentära bergarter som har genomgått olika grader av metamorfos under den kaledoniska orogenesen. I Östersunds centrala delar påträffas nästan enbart svartskiffer med låg metamorfosgrad. På flera platser i Östersund har det uppkommit skador på byggnader till följd av svällning i skiffern. Svällning uppstår när berggrunden exponeras för luft och vatten. Pyrit och kalcit som finns i skiffern reagerar och bildar gips, vilket orsakar volymökning. Under arbetet genomfördes laborativt svällförsök, där en del av proverna hölls torrt medan en del fuktades. Proverna undersöktes vidare med röntgendiffraktion för att kvantifiera mineralhalter. Svällförsöket genomfördes i syfte att utveckla en metod för bedömning av svällrisk i projekteringsskede för nya anläggningar i berg. För att förhindra skador till följd av svällning har flertal åtgärder testats, där försöken har inneburit att stänga ute syre från berggrunden genom att hålla berggrunden under grundvattennivån eller på olika sätt försegla exponerade bergytor. Det finns flertal faktorer som påverkar svällbenägenhet, i arbetet diskuteras bland annat påverkan av svavelhalt, pH och temperatur. Slutligen observerades &lt;0,1wt% gips i samtliga prover från undersökningsområdet genom XRD analys, samtliga prover hade även en låg halt av pyrit och magnetkis. De låga halterna och standardavvikelse för analysmetoden medförde att skillnad i mineralogi före och efter utfört svällförsök ej kunde påvisas. Det är fortsatt viktigt att ha i åtanke att berggrunden i området har rätt förutsättningar för svällning även om resultaten inte visar någon skillnad i gipshalt före och efter utfört svällförsök. / Jämtlands bedrock mainly consists of sedimentary rocks that has been metamorphosed during the Caledonian orogenesis. In the central parts of Östersund almost only black shale with a low grade of metamorphism is encountered. Damages on buildings has occurred due to swelling in shale in several places in Östersund. Swelling occurs when the bedrock is exposed to water and air. Pyrite and Calcite in the shale reacts and forms gypsum, which causes volume expansion. During this study laboratory swelling tests were performed, where one part of the samples was kept dry while the other part was exposed to water. The samples were examined with x-ray diffraction to quantify the mineral content. The swelling tests were performed with the purpose of evaluating XRD as a method for predicting the swelling risk in the early stage of planning for new facilities in the bedrock.To prevent damages caused by swelling several methods have been tested, where the attempts included shutting out oxygen from the bedrock by keeping it below the ground water level and by sealing the rock surface in different ways. There are multiple factors that affects the swelling risk, this work discusses influence from sulfur content, pH and temperature. Lastly &lt;0,1wt% gypsum was observed in all samples from the survey area through XRD analysis, a low amount of pyrite and pyrrhotite was also seen in all samples. The low amounts in combination with standard deviation in the analysis made it difficult to prove any difference in mineralogy due to the swelling tests. Hence it is still important to keep in mind that the bedrock in the area has the right conditions for swelling even though the results show no difference in the amount of gypsum between the dry and wet samples.