| 1. |
- Bäckström, Mattias, 1974-, et al.
(author)
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Fly ash injection into weathered mine waste
- 2013
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In: Annual International Mine Water Association Conference. - Colorado, USA : IMWA. - 9780615793856 ; , s. 513-519
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Conference paper (peer-reviewed)abstract
- By adding alkaline ashes through injection to weathered mine waste pH increased approximately 3 units, trace element was immobilized and flow rate decreased due to formation of hard pans. Reduction in trace element concentrations was around 96.9-99.6 % for copper, 94.7-99.7 % for zinc and 22.9-99.8 % for cadmium. For lead the best reduction was 97.3 % and the worst -393 % (increase). MSWI ashes performed worst with low buffering capacity and increase in vanadium and molybdenum concentrations.
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| 2. |
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| 3. |
- Karlsson, Lovisa, 1989-, et al.
(author)
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Release of metals from unprocessed and processed black shale due to natural weathering
- 2013
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In: Reliable Mine Water Technology. Volume 1. - Colorado, USA : IMWA. - 9780615793856 ; , s. 391-397
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Conference paper (peer-reviewed)abstract
- Black shale was mined and processed for recovery of hydrocarbons in Kvarntorp, some 200 km SW of Stockholm, Sweden, during 1942–66. Remains from the mining period is a deposit with 40 Mm³ of crushed shale residues: Unprocessed 3ne-grained shale as well as processed shale. The deposit is still hot; oxidation of sulphides as well as burning of hydrocarbons are still in progress some 50 years a1er closure. Weathering of the shale leads to releases of metal-rich leachates which will increase with time. The release of metals from pristine shale as well as weathered shale (exposed to the atmosphere for 50 years) and two di2erent processed shale residues have been studied using water of di2erent pH as leaching solution, to simulate extreme pH-variations in environmental waters: 3.0 (determined by oxidation of iron sulphides), 5.5 (bu2ered by carbon dioxide), 8.5 (bu2ered by calcite) and 12.5 (bu2ered by calcium hydroxide). Extraction of cationic elements was substantial (several percent of the total content) for Ca and Mg, as well as Ni, Co and U at pH 3, and very high (up to 50–60 %) for anionic elements (V, Mo, As) at pH 12.5. Especially the high-temperature processed shale would be a potential source for As and Mo at high pH. The pH-dependence of the weathering processes should be considered when future remediation (or metal recovery) processes and strategies are designed.
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| 4. |
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| 5. |
- Kasedde, Hillary, et al.
(author)
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Mineral recovery from Lake Katwe brines using isothermal evaporation
- 2013
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In: International Mine Water Association Annual Conference 2013. - : IMWA International Mine Water Association. - 9780615793856 ; , s. 855-860
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Conference paper (peer-reviewed)abstract
- Lake Katwe is a saline lake within the East African Rift system in Western Uganda, with a rich source of mineral salts. The present work aims at evaluating possibilities of future salt extraction from the lake deposit. An isothermal evaporation experiment was conducted on the lake brines. The precipitated salts were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods. Various economic salts such as thenardite, gypsum, mirabilite, burkeite, hanksite, anhydrite, trona, halite, nahcolite, thermonatrite, and soda ash precipitate from the lake brines. The experiments also reveal the sequence of mineral salt precipitation in the order sulfates→chlorides→carbonates.
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| 6. |
- Sartz, Lotta, 1979-, et al.
(author)
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Impact of temperature on weathering rates : a long term kinetic study on waste rock from Bergslagen, Sweden
- 2013
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In: Reliable Mine Water Technology. Volume 1. - Colorado, USA : IMWA. - 9780615793856 ; , s. 463-469
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Conference paper (peer-reviewed)abstract
- To assess the impact of different climatic conditions four weathering systems with waste rock from Bergslagen, Sweden, were followed. Secondary weathering products (ferrous and ferric sulphates and (oxy)hydroxides) on pyrite surfaces can slow down oxidation rates. It was investigated if repeated freezing/thawing could have an effect on the stability of the secondary product layer. After 90 weeks of weathering, freezing/thawing had not enhanced weathering rates, not even in combination with warm, humid air. Highest weathering rates were unexpectedly found in a reference system constantly kept at room temperature, and not in the more forceful humidity cell system.
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| 7. |
- Sjöberg, Viktor, 1984-, et al.
(author)
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Vegetation of historical mine waste from the Ljusnarsberg deposit with Agrostis capillaris : impact on leaching of copper
- 2013
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In: Reliable mine water technology. Proceedings of the International Mine Water Association Annual Conference 2013, Golden, Colorado, USA, August 6-9, 2013. - : Golden Co.. - 9780615793856 ; , s. 1119-1124
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Conference paper (peer-reviewed)abstract
- In Sweden there are hundreds of sites that need to be remediated due to high release of metals such as Cu. In order to minimize costs the methods should involve cheap materials and technical solutions. This study focuses on the possibility to establish Agrostis capillaris on sulfidic mine waste, after mixing with 30 % bark compost, and the subsequent release of Cu. Ini- tially the substrate produced leachates with pH 3.5 containing approximately 1 mg/L Cu. After 4 months the pH had increased to 4.5 and up to 80 % of the Cu was retained
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