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Natural weathering of shale products from KvarntorpKarlsson, Lovisa January 2011 (has links)
A severe shortage of many, to mankind, valuable elements are to be expected in the near future. Therefor is it of utmost importance to find these deposits and a way to refine the elements with as little negative effect on the environment as possible. One deposit of valuable elements such as U, V, Mo and Sr are the so called alum shale. Alum shale is a variety of sulfidic black shale which is rich in pyrite, FeS2, and organic carbon. Primary due to its contents of hydrocarbons and uranium the alum shale has been mined at different sites throughout Sweden. One of these sites was Kvarntorp in the region of Närke. The shale which had have its contents of hydrocarbons extracted through dry distillation was dumped into a heap that is now known as Kvarntorpshögen. The remaining hydrocarbons that this processed material still contain are to this day (2011) warm, with temperatures up to some hundred degrees Celsius. Due to this heat, infiltration of rainwater is held at a minimum. What no one knows however; is for how long Kvarntorpshögen will remain warm. Once it cools; many toxic elements will leak into the surrounding environment due to natural weathering caused by precipitation and frost wedging. The study also included a heating treatment of 70°C which is a temperature that the material of Kvarntorpshögen may be capable of generating by itself. This is assumed to be a good temperature for weathering processes; because it increases the kinetics of chemical reactions but also allows the presence of water. The results of this study shows that summer will be the season that contributes the most to the leaching of elements, of which some are toxic. Newly exposed surfaces of various shale materials often contain elements that is easily leached by water. Once this coat is washed away however, further leaching of that element decreases. Exceptions from this pattern in some shale products were shown by for example vanadium and molybdenum. The digestion data show that the completely processed shale, which makes up the majority of Kvarntorpshögen, still have a high content of rare and valuable elements. Making Kvarntorpshögen itself interesting for extraction processes in the future.
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Trace element leaching from alum shale fines and red ash from Kvarntorp during a large column testRydfjord, Helena January 2022 (has links)
Fuel shortage during the Second World War led to oil production in Kvarntorp, Kumla during 1942-1966 by pyrolyzing alum shale rich in pyrite, FeS2, and organic material such as kerogen. This production has led to a lot of waste laying deposited out in the open after the mining closed and has had negative environmental impact in the form of ongoing weathering and leaching of acidic water and leaching of trace elements into its surroundings. Chemical processes are still ongoing in this deposit, with temperatures reaching 700 °C on certain hotspots. Once the deposit cools down, precipitation will be able to enter the deposit and start leaching acidic water containing trace elements that will risk polluting groundwater in the surrounding areas. No one knows how many years it will take for the deposit to cool down, but it has been estimated to take at least 100 years.This study did leaching experiments on weathered fines as well as red ash in large columns while being oxygenated. Analyses consisted of ICP-MS, pH, electrical conductivity, acidity, alkalinity, and sulphate concentration.The results showed high concentrations of many valuable and potentially toxic elements in the leachates especially higher amounts of copper compared to previous studies.
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Water Courses in Kvarntorp : An Evaluation of Water Chemistry from Monitoring Data 1994-2012Karlsson, Lovisa January 2014 (has links)
The Kvarntorp area, some 200 km SW of Stockholm, Sweden, is a former mining site for alum shale. Kvarntorpshögen is a refuse dump from the hydrocarbon extraction during 1940-1965. The area is also dotted by abandoned quarries, which most are water filled today. The area is divided into two watersheds; the central and the eastern. Frommestabäcken is the main watercourse flowing out of the central watershed while Frogestabäcken is the corresponding watercourse in the eastern watershed. These two watercourses have been sampled annually since 1994 by consulting companies for the municipality of Kumla. The sampling sites at Ulftorpsbäcken (main inlet to the central watershed) and at the outlet from Serpentindammssystemet (the water treatment system in the central watershed) was added to the sampling program in 1997 and 1996 respectively. Other consulting companies have sampled the groundwater around Kvarntorpshögen (in 2004) and the water in the lake Norrtorpssjön (in 2004), which is an old water filled quarry. The lake Norrtorpssjön has also been sampled as part of a project performed by Örebro University. This thesis is a compilation and evaluation of all this data but the main part will be given focused on seasonal variations. Samples have been analysed with regard to the metals Na, K, Ca, Mg, Fe, Al, Li, B, As, Cu, Ni, Zn, Co, Cr, Cd, Pb, Mo, Sr and U. Other analysed parameters were tot-N, tot-P, bicarbonate (alkalinity), sulphate, chloride and the parameters pH, electrical conductivity and COD(Mn). Samples of bottom fauna have also been collected in Frommestabäcken. Concentration of most metals increased in the surface water while passing the Kvarntorp area. High metal concentrations were found for example in some of the groundwater samples. Such high concentrations were not observed in the samples from Frommestabäcken or Frogestabäcken, indicating for example dilution of metals or immobilisation through precipitation or adsorption. Seasonal effects on the dissolution and precipitation/adsorption of compounds were observed at all annually sampled watercourses. One of these effects was the spring- and autumn circulation of the lake Norrtorpssjön. The lake forms a thermocline during summer which causes higher concentrations of metals beneath the thermocline. During circulation these concentrations mixes throughout the depth profile which affects the amount of elements that is transported from the lake via Frogestabäcken. During winter the highest concentrations of metals are expected near the surface of the lake since the surface is colder than the rest of the water mass.
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Release of elements from unprocessed- and processed shale from Kvarntorp : Effect from different pHKarlsson, Lovisa January 2013 (has links)
The alum shale of Sweden is a sulphidic black shale which was mined for its contents of alum during the 17th-19th centuries. During the thirst half of the 20th century alum shale from Kvarntorp was pyrolysed for refinement of its organic matter. The refuse from the pyrolysis process were deposited in a deposit area which is today known as Kvarntorpshögen. This deposit is still hot due to on-going oxidation of the organic matter, pyrite oxidation and the neutralisation of acid by limestone. This heat generation prevents percolation of water to any greater extent due to evaporation. Once it cools the deposit will be susceptible to extraction. Three materials from the Kvarntorp deposit and a block of alum shale were sampled from the Kvarntorp area. These four materials were crushed, sieved and extracted. The extraction experiment was performed at controlled pH which corresponded to dissolution equilibrium of pyrite, carbon dioxide/oxygen, calcite and slaked lime. In the fifth extraction series the material was allowed to set the pH of the water phase. The extraction procedure lasted for 26 days. Metal content of the four shale materials were analysed by XRF (including contents of sulphur, phosphorous and chloride) and by digestion followed by ICP-MS analysis. Mineralogy of the four materials and the extraction residues were studied by XRD analysis. Metal concentrations of the aqueous samples were analysed by ICP-MS and concentrations of dissolved organic- and inorganic carbon by TOC. Electrical conductivity and concentrations of sulphate was also analysed in aqueous phases with non-manipulated pH. Sulphate and calcium concentrations were highest in aqueous samples from weathered fines indicating the presence of gypsum. Presence of gypsum was also confirmed by XRD. Gypsum indicates weathering since it is a neutralisation product of calcite and the sulphuric acid generated by pyrite oxidation. Concentrations of dissolved organic carbon in samples with pH 12.5 were found to be highest from red processed shale and lowest from samples of shale. This indicates different hydrolysis properties or origin of the organic matter in the materials. The majority of analysed metals had highest solid solution distribution under acidic, i.e. pH 3.0, conditions. Under these conditions it was samples from the relatively non-weathered shale that had the highest release of metals, with a few exceptions. At pH 12.5 high concentrations of V, As and Mo was extracted from almost all four materials. The red processed shale released the highest percentages of its total contents of V, As and Mo under these conditions; 28 %, 55 % and 61 % respectively. The high release of V, As and Mo from red processed shale was most likely a result from the pyrolysis process. The roasting induced the formation of oxides which then easily forms vanadate, arsenate and molybdate when exposed to water. Water percolating the Kvarntorp deposit in the future will initially most likely have a near neutral or slightly acidic pH. Lowest concentrations of metals were found in aqueous samples with pH between 5.5-8.5. There is a great risk that the pH of the drainage from the Kvarntorp deposit will in time become acidic due to depletion of buffering capacity. Thus the environmental threat will increase.
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Staten och skifferoljan : Om Svenska skifferoljeaktiebolaget 1941 till 1961 - ett beredskapsföretag i fredstidNäsman, Mattias January 2014 (has links)
Sammanfattning Uppsatsen undersöker historien om Svenska skifferoljeaktiebolaget (SSAB): de centrala aktörerna och de argument som de framförde för företagets uppstart, fortlevnad och sedermera nedläggning. Svenska skifferoljeaktiebolaget startades som ett beredskapsföretag under andra världskriget och fick vid krigsslutet status som ett "normalt långtidsföretag". Företaget hade en livslängd på 25 år, från 1941 till 1966. SSABs huvudsakliga ändamål vid starten var att utvinna olja ur alunskiffer i Kvarntorp, Närke, för att sedan sälja detta till marinen. SSAB var alltid helt ägt av staten och var beroende av stora mängder statligt kapital för att kunna finansiera verksamheten. Trots detta gav företaget aldrig ekonomisk avkastning och hade också svårt att nå upp till den förväntade produktionsmängden. Uppsatsen syfte är att försöka ge förståelse för varför ett företag av SSABs karaktär drevs vidare under så lång tid trots de stora kostnaderna för staten. Från uppstarten 1941 fram till beslutet om nedläggning 1961 ändrades argumentation kring fortsatta satsningar på SSAB. Från början var försörjningen av marinens grundläggande behov av drivmedel och smörjolja behov det viktigaste. Detta vidgades till att efter några år se SSABs då mer diversifierade produktion som nödvändig för beredskapen på fler varuområden. Mot slutet anfördes att den inhemsk oljeproduktion skulle kunna minska importbehovet och därmed bättra på handelsbalansen. I slutsatsen för uppsatsen argumenteras för att investeringar för SSABs utbyggnad och fortlevnad i första hand motiverades med att säkra beredskapen för drivmedel, men att investeringarna villkorades av att det fanns potential för framtida avkastning. Genom att använda forskning kring modernitetsmyten och myten om neutralitet kommer uppsatsen dra slutsatsen att den svenska neutralitetspolitiken och tron på den tekniska utvecklingen, samt att de investerade intressena var faktorer som var viktiga i SSABs fortlevnad.
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Samband mellan geologiska och bergmekaniska egenskaper i bergmaterial som bärlager till riksväg 51 : Riksväg 51 sträckan Svennevad - KvarntorpskorsetLandeman, Philip January 2018 (has links)
This thesis was created to ensure the quality of the rock which would be crushed to base layer construction material, in a road cut at Swedish highway 51, and to find a possible link between the rock's abrasion resistance and its mineralogy. Rock samples were collected, and among other things, several ball mill tests were carried out. The design of the road project was carried out by Loxia Group AB with NCC Group as contractor.A total of 18 rock samples and 2 base layer samples were taken in the area and they were all tested in a ball mill. The results showed that of the 18 rock samples, 2 samples had a ball mill value of less than 16 on the scale, 10 samples had values from 16 to 20, in addition to this, 3 samples had values from 20 to 21 and 3 samples had values in excess of 21 on the Swedish ball mill scale.Of the 3 samples with a ball mill value higher than 21, all contained a larger amount of biotite. Biotite did not appear to the same extent among the samples that ended up further down the ball mill scale. This link was so clear that a conclusion was subsequently drawn from this. The samples taken on the prefabricated base layer both had a ball mill value between 16 and 20. Overall, both the base layer and the rock material passed the Swedish Government’s Transport Administration’s requirements according to "TRVKB 10, Obundna lager". The rock type that was on the south part of the rock cut, adjacent to a deformation zone, had way too poor quality to undergo a ball mill test and therefore there are no values taken from that area.The conclusion of the work is that the rock material overall meets the Swedish Government’s Transport Administration’s requirements for base layer construction materials according to "TRVKB 10 Obundna lager", that a clear link between the proportion of biotite in a rock material and its abrasion resistance exists, and that the broken rock in the south should not be used as construction materials since the rock has insufficient mechanic capacity.
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