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  • 1.
    Allard, Bert
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sartz, Lotta
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kumla, Sweden.
    Sjöberg, Viktor
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sädbom, Stefan
    Bergskraft Bergslagen AB, Kumla, Sweden.
    Control of metal releases from historic sulphidic mine waste: Experience from the test site at the Ljusnarsberg mine field, Sweden (Project Bergskraft Bergslagen)2010Ingår i: Proc. EU Mine Drainage Research Exchange Conf. PADRE, June 11, Freiberg, Germany, 2010, s. 1 p-Konferensbidrag (Refereegranskat)
  • 2.
    Allard, Bert
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sartz, Lotta
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB.
    Sädbom, Stefan
    Bergskraft Bergslagen.
    Strategy for treatment of historic sulphidic mine waste: Experiences from the Ljusnarsberg Mine Field, Sweden2009Ingår i: Proc. 12th EuCheMS International Conference on Chemistry and the Environment, June 14-17, Stockholm, 2009, s. 197-Konferensbidrag (Refereegranskat)
  • 3.
    Allard, Bert
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Sartz, Lotta
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Metal releases from historic sulphidic mine site (Ljusnarsberg, Sweden): mobilization and attenuation processes2008Konferensbidrag (Refereegranskat)
  • 4.
    Angelstam, Per
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Andersson, Kjell
    Isacson, Maths
    Gavrilov, Dmitri V.
    Axelsson, Robert
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Degerman, Erik
    Elbakidze, Marine
    Kazakova-Apkarimova, Elena Yu.
    Sartz, Lotta
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sadbom, Stefan
    Törnblom, Johan
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Learning about the history of landscape use for the future: consequences for ecological and social systems in Swedish Bergslagen2013Ingår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 42, nr 2, s. 146-159Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Barriers and bridges to implement policies about sustainable development and sustainability commonly depend on the past development of social-ecological systems. Production of metals required integration of use of ore, streams for energy, and wood for bioenergy and construction, as well as of multiple societal actors. Focusing on the Swedish Bergslagen region as a case study we (1) describe the phases of natural resource use triggered by metallurgy, (2) the location and spatial extent of 22 definitions of Bergslagen divided into four zones as a proxy of cumulative pressure on landscapes, and (3) analyze the consequences for natural capital and society. We found clear gradients in industrial activity, stream alteration, and amount of natural forest from the core to the periphery of Bergslagen. Additionally, the legacy of top-down governance is linked to today's poorly diversified business sector and thus municipal vulnerability. Comparing the Bergslagen case study with other similar regions in Russia and Germany, we discuss the usefulness of multiple case studies.

  • 5.
    Bäckström, Mattias
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Domeij, Joel
    Sartz, Lotta
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Flooding of oxidized waste rock amended with alkaline by-products2010Ingår i: 34th British Columbia Mine Reclamation & 35th CLRA/ACRSD National Conference, 2010, s. 10 pages-Konferensbidrag (Refereegranskat)
    Abstract [en]

    Leaching of trace elements (Cd, Cu, Pb and Zn) from oxidized waste rock amended with different alkaline by-products was studied during flooding. It has been argued that water covers for oxidized waste would significantly increase leaching through reductive dissolution of the pre-formed hydrous ferric oxides and the associated trace elements. After approximately three weeks pH in the reference had reached 2.5 and 3.3 in the pore and overlying water, respectively. This can be compared with pH from 6.1 (water works granules) to above 10 (lime kiln dust) in the amended systems. It is clear that the carbonate dominated alkaline by-products have lower pH than the oxide/hydroxide based by-products. However, the systems amended with carbonate based by-products have significantly higher alkalinity. Cadmium, Cu, Pb and Zn concentrations within the waste decreased with at least 99% compared to the reference. In most systems the surface waters can even be used as drinking water. Cadmium, copper and zinc concentrations are clearly related to pH with decreasing concentrations with increasing pH. Lead concentrations, on the other hand, decrease to pH 8, where the concentrations start to increase slightly again due to the formation of soluble Pb(OH)₃⁻ and Pb(OH)₄²⁻ species. The results indicate that flooding of oxidized waste rock amended with alkaline by-products can be used as a successful remediation technique.

  • 6.
    Bäckström, Mattias
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Sartz, Lotta
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Fly ash injection into weathered mine waste2013Ingår i: Annual International Mine Water Association Conference: Reliable Mine Water Technology / [ed] Brown, A.; Figueroa, L. & Wolkersdorfer, Ch., Colorado, USA: IMWA , 2013, s. 513-519Konferensbidrag (Refereegranskat)
    Abstract [en]

    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.

  • 7.
    Bäckström, Mattias
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Sartz, Lotta
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Mixing of acid rock drainage with alkaline ash leachates: fate and immobilisation of trace elements2011Ingår i: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 222, nr 1-4, s. 377-389Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Acid rock drainage (ARD) from mine waste dumps often contains ferrous iron, sulphate and high concentrations of trace elements detrimental to the environment. Future costs will be enormous if the problem is not treated today. Simple, low maintenance, cost-effective methods for remediation of historical mine sites are therefore desired. In this study several mine waters were mixed with an alkaline ash leachtes in order to study the fate of the trace elements from both the mine waters (Cd, Cu, Pb, Zn, Ni and Co) and the ash leachates (Cr and Mo). It was found that the addition of ash water will precipitate hydrous ferric oxides (HFO) and hydrous aluminium oxides (HAO) and thereby inducing trace element sorption and co precipitation. It is also clear that the composition of the formed HFO/HAO mix determines the efficiency of the sorption for different trace elements. It is apparent that the amount of precipitating iron will determine the effectiveness of the removal of the trace elements. Sorption occurred much earlier (often one pH unit or more) in the system with high iron concentrations compared to the systems with lower iron concentrations. Removal of cadmium and zinc is difficult below pH 8 if the amount of precipitates is low. Using ash for generation of alkaline water may be a problem with regards to chromium and molybdenum. It is, however, possible to avoid problems with molybdenum by keeping the final pH around 7 and chromium(VI) from the ash water will be reduced into chromium(III) and precipitated as the hydroxide in the presence of iron(II) from the mine waters.

    The results imply that it is possible to also use fly ashes in alkaline leach beds in order to neutralize ARD followed by precipitation and sorption of trace elements.

  • 8.
    Bäckström, Mattias
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sartz, Lotta
    Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Permanent under water storing of weathered mine waste after removal of fine fraction and addition of ash2014Ingår i: An Interdisciplinary Response to Mine Water Challenges / [ed] Sui, W., Sun, Y. & Wang, C., Xuzhou: China University of Mining and Technology Press , 2014, s. 711-714Konferensbidrag (Refereegranskat)
    Abstract [en]

    Weathered sulphidic mine waste is a major environmental problem. An experiment was performed in order to study water covers for oxidized mine waste. In two experiments oxidized mine waste were covered with water, in one experiment the fine fraction was removed and in one experiment alkaline ash was also added prior to water covering. It was found that removal of the fine fraction decreased pH and increased trace element concentrations. Water covering of the mine waste with and without ash decreased trace element concentrations indicating that co disposing oxidized sulphidic mine waste and ash under water might be a promising remediation method.

  • 9.
    Bäckström, Mattias
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sartz, Lotta
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Stabilization of acid generating waste rock with fly ash: Immobilization of arsenic under alkaline conditions2010Ingår i: Mine water & innovative thinking: proceedings 2010 / [ed] Wolkersdorfer, C. and Freund, A., ovaScotia, Canada: Cape Breton University Press , 2010, s. 555-558Konferensbidrag (Refereegranskat)
    Abstract [en]

    A fly ash was used to increase pH and decrease arsenic leaching from an acidic mine waste.Both the amended system as well as the control system was leached with ultra pure water. pH in thecontrol increased from 1.7 to 2.7 at the end of the experiment while the pH in the amended systemdecreased from 12.6 to 11.5. compared to the control the initial concentrations of arsenic decreasedwith almost three orders of magnitude in the amended systems. A combination of co precipita-tion with iron and calcium arsenate precipitation were identified as the major arsenic immobi-lization mechanisms.

  • 10.
    Bäckström, Mattias
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sartz, Lotta
    Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Uranium leaching from a burning black shale deposit: Present conditions and future scenarios2015Ingår i: Uranium – Past and Future Challenges: Proceedings of the 7th International Conference on Uranium Mining and Hydrogeology / [ed] Broder, J; Arab, Alireza, Springer Publishing Company, 2015, s. 47-54Konferensbidrag (Refereegranskat)
    Abstract [en]

    During WW2 oil was produced through pyrolysis of alum shale giving rise to waste that was deposited in the open pits and in a waste deposit. The waste deposit still today has significantly elevated temperatures (above 500 °C). Remaining pyrite in the waste material has also led to ARD with elevated trace metal concentrations. The waste deposit is no great environmental problem today but as soon as the waste pile cools off both the volumes of drainage and concentration of uranium will increase significantly.

  • 11.
    Bäckström, Mattias
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sartz, Lotta
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kumla, Sweden.
    Use of multivariate statistics in order to understand the flow of acid rock drainage from an abandoned mining site2016Ingår i: Journal of Environmental Protection, ISSN 2152-2197, E-ISSN 2152-2219, Vol. 7, nr 3, s. 358-371Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pathways for acid rock drainage from an abandoned mining site (sulphidic ore) were investigated by analysing ground, seepage and surface waters. It was found that in affected ground and seepage waters pH was lower (average pH 5.0); sulphate higher (average 350 mg/L) and trace element concentrations were significantly increased (4330 μg/L copper and 7700 μg/L zinc) compared to surrounding waters. Multivariate statistics (principal component analysis) were used on the data set. Obtained loading plot showed a clear negative correlation between pH and parameters found at high concentrations, indicating that these parameters are found at the source term (acid rock drainage). Lead was also found in close proximity to iron and turbidity indicating that lead might be associated with particles. The score plot presented almost all samples from high concentrations to low concentrations along the first principal component (explaining 63% of the variation in the data set) indicating that dilution was an important mechanism for the decrease in concentrations as opposed to immobilisation on surfaces along the flowpath. Decrease in fluoride and sulphate along one of the suspected flowpath coincided with an increase in calcium. Through geochemical calculations it was concluded that calcite (CaCO3) dissolved along the flowpath and thus induced precipitation of gypsum (CaSO4) and fluorite (CaF2). Through a combination of PCA and geochemical calculations the most likely flowpaths for contaminated water from the abandoned mining site were presented, making it possible to prevent further negative effects on the surface water.

  • 12.
    Bäckström, Mattias
    et al.
    Örebro universitet, Institutionen för naturvetenskap.
    Sartz, Lotta
    Örebro universitet, Institutionen för naturvetenskap.
    Karlsson, Stefan
    Örebro universitet, Institutionen för naturvetenskap.
    Multielement contamination at a skeet and trap shooting range: II: seasonal and spatial variations in surface and groundwatersManuskript (preprint) (Övrigt vetenskapligt)
  • 13.
    Bäckström, Mattias
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Sartz, Lotta
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Allard, Bert
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Prevention of ARD through stabilization of waste rock with alkaline by-products: results from a meso-scale experiment2010Ingår i: Mina Water & Innovative Thinking: proceedings 2010 / [ed] Wolkersdorfer, C. & Freund, A, Nova Scotia, Canada: Cape Breton University Press , 2010, s. 559-563Konferensbidrag (Refereegranskat)
  • 14.
    Bäckström, Mattias
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sartz, Lotta
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Larsson, Erik
    Bergskraft Bergslagen, Kopparberg, Sweden.
    Karlsson, Stefan
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Properties of alkaline materials for injection into weathered mine waste piles: methods and initial pilot trials2011Ingår i: Mine water: managing the challenges: proceedings of the International Mine Water Association Congress 2011 / [ed] Rüde, Thomas R.; Freund, Antje; Wolkersdorfer, Christian, Aachen: RWTH , 2011, s. 265-269Konferensbidrag (Refereegranskat)
    Abstract [en]

    Several alkaline materials were studied with regards to their ability to form stable suspensions withwater. Gravitational injection of alkaline materials were performed into weathered mine waste in two differentpilot scales (25 L and 1 000 L). When water was added after injection lime mud (LM) was flushed out whilelime kiln dust (LKD) and green liqour (GLD) remained within the mine waste. Deconstruction of the pilot sys-tems showed that both materials had penetrated the voids present. LKD and GLD increased pH significantlyand reduced trace metal concentratios. It is concluded that both LKD and GLD are suitable for stabilizing acidgenerating mine waste.

  • 15.
    Bäckström, Mattias
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sartz, Lotta
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kumla, Sweden.
    Sädbom, Stefan
    Bergskraft Bergslagen AB, Kumla, Sweden.
    Mining Waste as an Exploration Tool and Secondary Resource2017Ingår i: Mine Water & Circular Economy / [ed] Wolkersdorfer, C., Sartz, L., Sillanpää, M. and Häkkinen, A, Lappeenranta, Finland: Lappeenranta University of Technology , 2017, Vol. II, s. 964-971Konferensbidrag (Refereegranskat)
    Abstract [en]

    There is today no overall information about how much mining waste there is in Sweden and what it contains. This project focused on samples from waste rock, tailings and slag from the historical mining region Bergslagen, Sweden. Modern dissolution and analytical methods were used in order to determine approximately 50 elements in the samples. Modern analytical data for the historical mining waste is useful as an exploration tool and can provide information about remaining or new resources underground. Results show that there is a potential for recovery of critical elements from mining waste as well as dealing with environmental problems.

  • 16.
    Ekblom, Sanna
    et al.
    Örebro University, Örebro, Sweden.
    Sartz, Lotta
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Treatment of Historical Mining Waste using different Incineration Ashes2017Ingår i: Mine Water & Circular Economy / [ed] Wolkersdorfer, C., Sartz, L., Sillanpää, M. and Häkkinen, A, Lappeenranta, Finland: Lappeenranta University of Technology , 2017, Vol. II, s. 1125-1132Konferensbidrag (Refereegranskat)
    Abstract [en]

    ARD from historical mining sites in Sweden is a major source for trace elements to surface waters. In order to be able to treat a large portion of these sites cost effective reclamation methods is necessary. Incineration ashes were used in leaching tests to study their effect on a highly weathered mining waste in order to neutralize acidity and immobilize trace elements. This study shows that ashes can be used to increase pH and decrease trace element mobility from oxidized mining waste. Increased leaching of Cl, Mo and Sb, however, needs to be considered for waste fuel ashes before use.

  • 17.
    Fahlqvist, Linnea
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen, Kopparberg, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sartz, Lotta
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Allard, Bert
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Removal of uranium from a neutral mine water using uncoated and iron oxyhydroxide coated iron tailings2013Ingår i: Annual International Mine Water Association Conference: Reliable Mine Water Technology / [ed] Brown, A.; Figueroa, L. & Wolkersdorfer, Ch., Colorado, USA: IMWA , 2013, s. 551-557Konferensbidrag (Refereegranskat)
  • 18.
    Fahlqvist, Linnea
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sartz, Lotta
    Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Removal of zinc and lead from a neutral mine water using iron tailings and iron oxyhydroxide coated iron tailings2012Ingår i: Mine Water and the Environment / [ed] McCullough, C.D., Lund, M.A. and Wyse, L., International Mine Water Association (IMWA) , 2012, s. 584A-584GKonferensbidrag (Refereegranskat)
  • 19.
    Karlsson, Stefan
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sartz, Lotta
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Allard, Bert
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Abatement of ARD with solid alkaline waste materials: A meso-scale field test with emphasis on general hydrochemical parameters2009Ingår i: Securing the Future and 8th ICARD, 2009, s. 10 pages-Konferensbidrag (Refereegranskat)
    Abstract [en]

    Abatement of acid mine drainage (ARD) can be made by controlling pH and Eh of the effluents, to optimise retention of major and trace components. The use of solid alkaline waste products from lime production, pulp and paper industry and steel production as well as ashes from bio fuels was evaluated in a meso-scaleexperiment. Each test system hadthree 0.4 m3barrelsthat contained the alkaline waste, a passive support and peat nuggets, in this order.The alkaline wastes consisted of lime kiln dust (LKD), green liquor dreg (GLD), lime mud (LM), LD-slag and fresh and aged ashes. The ARD came either from reactors with acid waste or water taken from a nearby mine shaft. Neutralization was observed for fresh ash, LKD, LD and LM/ash with pH of 6.5, 8.9, 5.3 and 6.6, respectively. The corresponding alkalinities were 0.3, 10.1, 1.8 and 0.5 meqv/l. For carbonated ash and GLD the pH was 3.9 and 4.7 and with acidity remaining. In the best performing systems the average trace metal retention was Pb (>99%), Cu (>99%), Cd (90%) and Zn (70%).

  • 20.
    Saqib, Naeem
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sartz, Lotta
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Chemical leaching of Zn, Cu and Pb from oxidized sulfidic mining waste followed by stabilization using green liquor dregManuskript (preprint) (Övrigt vetenskapligt)
  • 21.
    Sartz, Lotta
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Alkaline by-products as amendments for remediation of historic mine sites2010Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Gruvindustrin är sedan länge av stor ekonomisk vikt för Sverige och gruvorna harhaft stor betydelse för vår välfärd även historiskt sett. Av den malm som bryts ärca en fjärdedel järnmalm och tre fjärdedelar sulfidmalm. Vid malmbrytning bildasstora mängder avfall, vilket tas om hand av verksamhetsutövaren som bäransvaret för miljöpåverkan. Läckage från deponier för sulfidhaltigt material kange upphov till omfattande påverkan på den omgivande miljön genom försurningoch spridning av (tung)metaller. För att förhindra försurning täcks vanligtvisavfallet med jord eller vatten. Detta gör man för att förhindra sulfidoxidationsom kan leda till att surt och metallrikt lakvatten transporteras ut från en deponi.I Bergslagen finns ett stort antal historiska gruvområden i behov av åtgärd, dåde kan utgöra ett hot mot både människors hälsa och miljö. Uppskattningsvisfinns gruvavfallsmaterial i storleksordningen varp 3 miljoner m3, sand 14miljoner m3 respektive slagg 1,5 miljoner m3 som är aktuellt för efterbehandling iDalarnas, Västmanlands och Örebros län. Kostnaderna för efterbehandling avdessa områden beräknas uppgå till mellan två och tre miljarder svenska kronor.Äldre avfall skiljer sig i regel från nyproducerat avfall med avseende på avfalletsmetallinnehåll och vittringsgrad samt problem med ansvarsfrågor och frågorrörande kulturhistoriska värden.Vid historisk gruvbrytning (före 1900) fanns inte lika effektiva sorteringsmetoderoch anrikningsprocesser som idag. Således innehåller historisktgruvavfall generellt sett högre metallhalter. Avfall från historiskt gruvavfall harockså varit exponerat för luftens syre, nederbörd och erosion under lång tid.Detta har medfört att en stor andel av det järn som finns närvarande är trevärt(dess oxiderade form), vilket gör att oxidation kan fortgå även om man täckeravfallet.Alkaliska restprodukter från fyra olika branscher, representerade av kalkindustrin,stålindustrin, pappersmassaindustrin samt energiproducentindustrin,har under fyra år studerats för att bestämma deras lämplighet för olika typer avefterbehandlingar av vittrat, surt gruvavfall. Försök har gjorts i labskala, samtstörre pilotskaleförsök, hädanefter benämnda mesoskala. Laboratorie-försökenhar syftat till att utreda neutraliseringspotential, lämpliga inblandningsproportioneroch eventuella metalläckage från de alkaliska materialen. Försökensom gjorts i mesoskala har dels syftat till att studera effekter av att blanda vittrat,sulfidrikt gruvavfall med alkaliska material, så kallade stabiliseringsförsök.Därutöver har försök gjorts med syfte att rena lakvatten från gruvavfall. I detsenare försöket har de alkaliska materialen placerats i 0,4 m3-behållare och surt,metallrikt lakvatten har låtits passera, med pH-ökning och metallfastläggningsom följd.Utifrån resultaten kan vissa av materialen anses ha god förmåga attneutralisera gruvavfallet eller lakvatten från gruvavfallet samt minska utläckageav tungmetaller såsom koppar, zink, kadmium och bly. För dessa materialplaneras i nuläget för fortsatta försök i fullskala. För de material som intefungerat tillfredställande nog för att fortsätta i fullskala kommer ytterligarestudier samt modifikationer av metodiken att utföras, t ex kommer merreducerande förhållanden att försöka uppnås genom att försöksbehållarna täcksmed syreförbrukande material, t ex rötslam.

    Delarbeten
    1. Mixing of acid rock drainage with alkaline ash leachates: formation of solid precipitates and pH-buffering
    Öppna denna publikation i ny flik eller fönster >>Mixing of acid rock drainage with alkaline ash leachates: formation of solid precipitates and pH-buffering
    2010 (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Three metal-rich and acidic mine waters (from Bersbo and Ljusnarsberg, Sweden) were mixed with alkaline fly ash leachates in various proportions, representing a pH-titration. The changes in pH, as well as the loss of metals in solution due to precipitation of solid phases, were followed. Mineral equilibria and changes in pH and alkalinity were simulated with the geochemical code PHREEQC using the MINTEQv4 database, and comparisons between measured and simulated pH-responses were made.

    The formation of solid precipitates corresponded to fairly well-defined pH-buffering regions, reflecting the composition of the mine waters (notably the levels of Fe, Al and Mn). For the mine waters not dominated by iron the precipitation of zinc had a distinct buffering effect at near-neutral pH. The formation of solid magnesium phases (carbonate, as well as hydroxide) was indicated at high pH (above 9), but no formation of solid calcium phases despite high sulfate levels. The phases that precipitate were various amorphous mixtures, mostly of the metals Fe, Al, Mn, Zn and Mg.

    For the iron-rich mine water, pH was poorly simulated with a simple MIX-model, while alkalinity predictions agreed reasonably well with measured data. For the aluminum-rich mine waters the simulated pH-responses agreed well with the measurements.

    Nyckelord
    pH-buffering, iron, aluminum, PHREEQC
    Nationell ämneskategori
    Miljövetenskap
    Forskningsämne
    Miljövetenskap
    Identifikatorer
    urn:nbn:se:oru:diva-12006 (URN)
    Tillgänglig från: 2010-10-05 Skapad: 2010-10-05 Senast uppdaterad: 2019-03-26Bibliografiskt granskad
    2. Mixing of acid rock drainage with alkaline ash leachates: fate and immobilisation of trace elements
    Öppna denna publikation i ny flik eller fönster >>Mixing of acid rock drainage with alkaline ash leachates: fate and immobilisation of trace elements
    2011 (Engelska)Ingår i: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 222, nr 1-4, s. 377-389Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Acid rock drainage (ARD) from mine waste dumps often contains ferrous iron, sulphate and high concentrations of trace elements detrimental to the environment. Future costs will be enormous if the problem is not treated today. Simple, low maintenance, cost-effective methods for remediation of historical mine sites are therefore desired. In this study several mine waters were mixed with an alkaline ash leachtes in order to study the fate of the trace elements from both the mine waters (Cd, Cu, Pb, Zn, Ni and Co) and the ash leachates (Cr and Mo). It was found that the addition of ash water will precipitate hydrous ferric oxides (HFO) and hydrous aluminium oxides (HAO) and thereby inducing trace element sorption and co precipitation. It is also clear that the composition of the formed HFO/HAO mix determines the efficiency of the sorption for different trace elements. It is apparent that the amount of precipitating iron will determine the effectiveness of the removal of the trace elements. Sorption occurred much earlier (often one pH unit or more) in the system with high iron concentrations compared to the systems with lower iron concentrations. Removal of cadmium and zinc is difficult below pH 8 if the amount of precipitates is low. Using ash for generation of alkaline water may be a problem with regards to chromium and molybdenum. It is, however, possible to avoid problems with molybdenum by keeping the final pH around 7 and chromium(VI) from the ash water will be reduced into chromium(III) and precipitated as the hydroxide in the presence of iron(II) from the mine waters.

    The results imply that it is possible to also use fly ashes in alkaline leach beds in order to neutralize ARD followed by precipitation and sorption of trace elements.

    Ort, förlag, år, upplaga, sidor
    Springer, 2011
    Nyckelord
    HFO, HAO, chromium, molybdenum, PHREEQC
    Nationell ämneskategori
    Miljövetenskap
    Forskningsämne
    Miljökemi
    Identifikatorer
    urn:nbn:se:oru:diva-12007 (URN)10.1007/s11270-011-0831-8 (DOI)000296632900028 ()2-s2.0-80755153691 (Scopus ID)
    Tillgänglig från: 2010-10-05 Skapad: 2010-10-05 Senast uppdaterad: 2019-03-26Bibliografiskt granskad
    3. Laboratory mixing of oxidized mine waste with different alkaline by-products (LD-slag, lime kiln dust and fly ash)
    Öppna denna publikation i ny flik eller fönster >>Laboratory mixing of oxidized mine waste with different alkaline by-products (LD-slag, lime kiln dust and fly ash)
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Neutralization and metal removal efficiency were studied for mixtures of alkaline waste materials and oxidized mine waste. Leaching of the mixtures were performed during 65 days at an L/S ratio of 10-18.

    It was found that as pH increased the trace element concentrations from the mine waste (mainly Cd, Cu, Pb and Zn) were immobilized through sorption and partly precipitation at higher pH. However, as the amount of alkaline amendments increased leaching of anionic trace elements (Cr, Mo, Se and V) from the alkaline by-products were noticed. For LD leaching of vanadium was particularly significant and showed increasing concentrations with time. It was also found that the anionic trace elements had a maximum leaching at pH around 10-11, where sorption became important. It is thus important to keep pH below 10 in order to minimize the anionic leaching. Optimum pH for immobilization of trace elements from the mine waste was therefore found to be between 8 and 10. Optimum pH can be achieved by addition of around 20-30 % fly ash or by 5-10 % LD or LKD. For the highly alkaline materials there is a significant risk that the resulting pH from a remediation will be higher than 10, which will lead to increased leaching of several anionic trace elements. For the fly ashes the problem is the opposite with risk of obtaining a pH to low to immobilize especially zinc.

    Nyckelord
    pH, copper, lead, zinc, vanadium
    Nationell ämneskategori
    Miljövetenskap
    Forskningsämne
    Miljövetenskap
    Identifikatorer
    urn:nbn:se:oru:diva-12008 (URN)
    Tillgänglig från: 2010-10-05 Skapad: 2010-10-05 Senast uppdaterad: 2019-03-26Bibliografiskt granskad
    4. Chemical stabilization of historic mine waste using alkaline paper mill by-products: batch mixing experiments
    Öppna denna publikation i ny flik eller fönster >>Chemical stabilization of historic mine waste using alkaline paper mill by-products: batch mixing experiments
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Neutralization of acid-generating sulphidic mine waste by mixing with three alkaline paper mill by-products (lime mud, green liquor dregs and fly ash) were studied in batch experiments. An initial liquid/solid (L/S) ratio of 10 was used, where after the mixtures were diluted at four occasions (corresponding to L/S 12, 14, 16 and 18).

    pH in the control was 3.3 to 3.1 (slightly decreasing with time/leach day) while pH in the amended systems was increased with three to four pH-units compared to the control. An amendment of 5 % was sufficient to increase pH to 7 and slightly above. A mixture of alkalinities from lime mud and fly ash (carbonate and hydroxide), did not increase pH more than the pure lime mud amendment, except at a very high amendment (50 %).

    Trace element immobilizations (Cu, Zn, Cd, Pb) were almost quantitative: Concentrations in amended systems were decreased compared to the control with more than 97 %. Immobilization of lead was pH-dependent, while zinc and copper did not show such strong correlation with pH. The main trace element immobilization mechanism was probably sorption onto formed iron oxy(hydr)oxides and/or coprecipitation.

    Elements that might increase due to amendment of the alkaline materials were chromium, vanadium and molybdenum. Chromium was present at highest concentrations in the green liquor dreg, and leaching of chromium (around 600 µg/l) was also observed from this material. Leached chromium concentrations in the green liquor dreg amended systems were however decreased due to lowered pH and Cr(OH)3 precipitation.

    Nyckelord
    carbonate neutralization, trace metals, lime mud, green liquor dregs, fly ash
    Nationell ämneskategori
    Miljövetenskap
    Forskningsämne
    Miljövetenskap
    Identifikatorer
    urn:nbn:se:oru:diva-12009 (URN)
    Tillgänglig från: 2010-10-05 Skapad: 2010-10-05 Senast uppdaterad: 2019-03-26Bibliografiskt granskad
    5. Long-term leaching of fly ash with ARD: pH-dependent accumulation and release of trace elements
    Öppna denna publikation i ny flik eller fönster >>Long-term leaching of fly ash with ARD: pH-dependent accumulation and release of trace elements
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    In most ARD treatments, various alkaline sources are used to neutralize the acid produced. Utilization of highly alkaline fly ashes instead of raw materials is a cost-effective alternative, which lately have become increasingly popular.

    In laboratory batch experiments, neutralizing capacity for fly ash was studied during 20 days in two parallel series. ARD was added to fly ash once a day, for each increment the liquid to solid ratio (L/S ratio) was increased (final L/S around 3 000).

    At an early stage of the experiment (L/S ratio 12), the concentration of barium in solution unexpectedly increased from 200 to 10 000 µg/l. pH showed a slight increase during these observations (pH 12.4-12.7). Furthermore, concentrations of chromium and molybdenum noticeably decreased at these distinct L/S ratios. The decrease of chromium and molybdenum is suggested to be due to incorporation into the interlayer regions of hydrocalumite (Ca4Al2(OH)12(OH)2∙6H2O), replacing the hydroxide groups, which also explain the increase in pH.

    Trace elements (Cd, Cu, Pb and Zn) from the added ARD were effectively removed from the solution (93-96 %) and were not released until pH dropped below 7. Major mechanism behind the immobilization of trace elements is sorption onto newly formed HAO/HFO.

    Large differences were seen between leaching with different leaching media (distilled water or ARD), why the use of site-specific materials and reagents are crucial in experiments evaluating possible use in field applications.

    Nyckelord
    Barium, hydrocalumite, neutralizing capacity
    Nationell ämneskategori
    Miljövetenskap
    Forskningsämne
    Miljövetenskap
    Identifikatorer
    urn:nbn:se:oru:diva-12010 (URN)
    Tillgänglig från: 2010-10-05 Skapad: 2010-10-05 Senast uppdaterad: 2019-03-26Bibliografiskt granskad
    6. Leaching of lime kiln dust and LD-slag with ARD in a sequential batch experiment
    Öppna denna publikation i ny flik eller fönster >>Leaching of lime kiln dust and LD-slag with ARD in a sequential batch experiment
    2010 (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Treatment of ARD in a reactive barrier or an alkaline filter prior to release to the recipient is a desired and often suggested alternative. Alkaline candidate materials for the purpose that are cheap are by-products such as fly ash, lime kiln dust and different steel slags. An experiment was carried out where two highly alkaline by-products (LD slag and lime kiln dust) were exposed to a real ARD in sequential batch design.

    It was found that the buffering capacity was high enough in both materials in order to neutralize the added ARD even if large portions of the total buffering capacity was washed out during the experiment. Washing out of alkalinity is a greater problem for oxide/hydroxide materials than it is for carbonate dominating materials. Calculations indicated that the buffering capacity in the LKD would last at least until L/S 3 000 while it would last approximately until L/S 1 000 for LD slag. Lack of buffering capacity is thus not the major problem with the materials, but rather the lack of capacity for trace element immobilization. Including sorption onto HFO and HAO and precipitation of different hydroxides and carbonates the already immobilized trace elements from the added ARD started to be remobilized around pH 8. Below pH 8 concentrations increased rapidly due mainly to desorption and was soon found to be higher than in the added ARD.

    Some of the divalent elements (Mg and Mn) were also found to be controlled by their hydroxides at high pH and at circumneutral pH by their carbonates. This results in higher concentrations at lower pH (below 10) since the carbonates are more soluble than the hydroxides.

    It is important to characterize the used alkaline by-products at the expected chemical conditions in order to be able to assess potential trace element leaching (most likely anionic elements such as vanadium and chromium).

    Nyckelord
    HFO, HAO, pH, vanadium, trace elements
    Nationell ämneskategori
    Miljövetenskap
    Forskningsämne
    Miljövetenskap
    Identifikatorer
    urn:nbn:se:oru:diva-12011 (URN)
    Tillgänglig från: 2010-10-05 Skapad: 2010-10-05 Senast uppdaterad: 2019-03-26Bibliografiskt granskad
    7. Paper mill by-products and fly ash as amendments to oxidized waste rock: neutralization and trace metal reduction in a meso-scale field study
    Öppna denna publikation i ny flik eller fönster >>Paper mill by-products and fly ash as amendments to oxidized waste rock: neutralization and trace metal reduction in a meso-scale field study
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Remediation of oxidized mine waste is often hampered by the risk of reductive dissolution of ferric iron phases and the resulting release of trace elements. In order to partly avoid this problem the oxidized mine waste can be amended with an alkaline material. In this meso-scale experiment with 7 different amended systems and a control an oxidized waste rock was mixed with several alkaline by-products and leachates were collected for 44 months. Results show that pH in the amended systems increased between 1.1 and 2.2 pH units compared to the untreated reference (pH 4.4). The increase in pH resulted in a significant decrease in trace element concentrations, averaging a concentration reduction around 97 %. Sorption was probably the main reduction mechanism.

    Flow rate measurements in the different systems showed a strong correlation between pH and the flow rate. It was concluded that the type of alkaline material and the number of alkaline layers were of less importance than the flow rate when it came to quality of the leachates. However, fly ashes were found in all the best performing systems. Longer residence time clearly improves the quality of the leachates. When it comes to comparison of the different systems it seems that systems containing fly ashes performed best. Least effective systems contained green liquor dregs and amendments with too little fly ash. It is clear that alkaline materials can be used in order to reduce the leaching of trace elements from historical mine waste deposits.

    Nyckelord
    lime mud, green liquor dreg, fly ash
    Nationell ämneskategori
    Miljövetenskap
    Forskningsämne
    Miljövetenskap
    Identifikatorer
    urn:nbn:se:oru:diva-12012 (URN)
    Tillgänglig från: 2010-10-05 Skapad: 2010-10-05 Senast uppdaterad: 2019-03-26Bibliografiskt granskad
    8. Successive neutralization, precipitation and trace metal immobilization in meso-scale filters for ARD treatment
    Öppna denna publikation i ny flik eller fönster >>Successive neutralization, precipitation and trace metal immobilization in meso-scale filters for ARD treatment
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Six alkaline by-products were studied in reactive filters (3×0.4 m3) built on the historic mine site Ljusnarsbergsfältet, Kopparberg, Sweden. Each filter was made out of three connected sections in a sequence (neutralization – oxidation (precipitation) – sorption). Total buffering capacity of the alkaline materials was found to have a minor impact on their respective performances. Other chemical and physical circumstances were more important, e.g. carbonation, iron precipitation and preferential flow path formations. A combination of fresh fly ash and lime mud had similar chemical responses as a carbonated fly ash. These filters were also the worst performers, considering overall trace element immobilizations.

    No particular differences were found between two different passive adsorbents in the oxidation stage, where iron and aluminum were intended to precipitate and act as sorbent phases for other elements: Cu, Zn, Cd, and Pb. In general it was found that highly alkaline materials containing alkalinities as CaO/Ca(OH)2 were superior to materials with carbonate alkalinity.

    Nyckelord
    lime mud, fly ash, green liquor dreg, lime kiln dust, LD-slag, water works granules
    Nationell ämneskategori
    Miljövetenskap
    Forskningsämne
    Miljövetenskap
    Identifikatorer
    urn:nbn:se:oru:diva-12013 (URN)
    Tillgänglig från: 2010-10-05 Skapad: 2010-10-05 Senast uppdaterad: 2019-03-26Bibliografiskt granskad
  • 22.
    Sartz, Lotta
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Chemical stabilization of historic mine waste using alkaline paper mill by-products: batch mixing experimentsManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Neutralization of acid-generating sulphidic mine waste by mixing with three alkaline paper mill by-products (lime mud, green liquor dregs and fly ash) were studied in batch experiments. An initial liquid/solid (L/S) ratio of 10 was used, where after the mixtures were diluted at four occasions (corresponding to L/S 12, 14, 16 and 18).

    pH in the control was 3.3 to 3.1 (slightly decreasing with time/leach day) while pH in the amended systems was increased with three to four pH-units compared to the control. An amendment of 5 % was sufficient to increase pH to 7 and slightly above. A mixture of alkalinities from lime mud and fly ash (carbonate and hydroxide), did not increase pH more than the pure lime mud amendment, except at a very high amendment (50 %).

    Trace element immobilizations (Cu, Zn, Cd, Pb) were almost quantitative: Concentrations in amended systems were decreased compared to the control with more than 97 %. Immobilization of lead was pH-dependent, while zinc and copper did not show such strong correlation with pH. The main trace element immobilization mechanism was probably sorption onto formed iron oxy(hydr)oxides and/or coprecipitation.

    Elements that might increase due to amendment of the alkaline materials were chromium, vanadium and molybdenum. Chromium was present at highest concentrations in the green liquor dreg, and leaching of chromium (around 600 µg/l) was also observed from this material. Leached chromium concentrations in the green liquor dreg amended systems were however decreased due to lowered pH and Cr(OH)3 precipitation.

  • 23.
    Sartz, Lotta
    et al.
    Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Chemistry and environmental science research as a part of education: An example from Sweden2014Ingår i: 1st International Congress and Exhibition on Current Trends on Science and Technology Education (SCITEED 2014) / [ed] Oral, A.Y. and Bahsi, Z.B., Curran Associates, Inc., 2014, s. 27-32Konferensbidrag (Refereegranskat)
  • 24.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kumla, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Development of a low-tech treatment for neutral mine water: a case study2016Ingår i: Mining Meets Water: Conflicts and Solutions / [ed] Drebenstedt, C. & Paul, M., Freiberg, Germany: TU Bergakademie Freiberg, Institute of Mining and Special Civil Engineering , 2016, s. 913-918Konferensbidrag (Refereegranskat)
    Abstract [en]

    Lovisagruvan is a Pb-Zn-Ag mine in mid-south Sweden, with a yearly production of some 40 000 tons. There are four main levels in the mine: 55, 105, 145 and 190 m below ground. Water is continously pumped at a rate of 5 m3/h, passing sedimentation pools at each of the four main levels in the mine and finally one above ground. A modified backfill mining is used and in order to visually separate the ore from the waste rock limestone is used as a separating layer. Limestone addition in combination with non-acid producing mineralisation generates a pH-neutral mine water. For many years the mine has had problems with high levels of zinc and lead in the mine water released to recipient. The primary contaminants, lead and zinc, were mainly found as particles or associated to particles. With a combination of several measures including a sandfilter and FeSO4 addition suspended matter was reduced 93 %, lead 91 % and zinc 71 %.

  • 25.
    Sartz, Lotta
    et al.
    Bergskraft Bergslagen, Kopparberg, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Impact of temperature on weathering rates: a long term kinetic study on waste rock from Bergslagen, Sweden2013Ingår i: Annual International Mine Water Association Conference: Reliable Mine Water Technology / [ed] Brown, A.; Figueroa, L. & Wolkersdorfer, Ch., Colorado, USA: IMWA , 2013, s. 463-469Konferensbidrag (Refereegranskat)
    Abstract [en]

    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.

  • 26.
    Sartz, Lotta
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Laboratory mixing of oxidized mine waste with different alkaline by-products (LD-slag, lime kiln dust and fly ash)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Neutralization and metal removal efficiency were studied for mixtures of alkaline waste materials and oxidized mine waste. Leaching of the mixtures were performed during 65 days at an L/S ratio of 10-18.

    It was found that as pH increased the trace element concentrations from the mine waste (mainly Cd, Cu, Pb and Zn) were immobilized through sorption and partly precipitation at higher pH. However, as the amount of alkaline amendments increased leaching of anionic trace elements (Cr, Mo, Se and V) from the alkaline by-products were noticed. For LD leaching of vanadium was particularly significant and showed increasing concentrations with time. It was also found that the anionic trace elements had a maximum leaching at pH around 10-11, where sorption became important. It is thus important to keep pH below 10 in order to minimize the anionic leaching. Optimum pH for immobilization of trace elements from the mine waste was therefore found to be between 8 and 10. Optimum pH can be achieved by addition of around 20-30 % fly ash or by 5-10 % LD or LKD. For the highly alkaline materials there is a significant risk that the resulting pH from a remediation will be higher than 10, which will lead to increased leaching of several anionic trace elements. For the fly ashes the problem is the opposite with risk of obtaining a pH to low to immobilize especially zinc.

  • 27.
    Sartz, Lotta
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Long-term leaching of fly ash with ARD: pH-dependent accumulation and release of trace elementsManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    In most ARD treatments, various alkaline sources are used to neutralize the acid produced. Utilization of highly alkaline fly ashes instead of raw materials is a cost-effective alternative, which lately have become increasingly popular.

    In laboratory batch experiments, neutralizing capacity for fly ash was studied during 20 days in two parallel series. ARD was added to fly ash once a day, for each increment the liquid to solid ratio (L/S ratio) was increased (final L/S around 3 000).

    At an early stage of the experiment (L/S ratio 12), the concentration of barium in solution unexpectedly increased from 200 to 10 000 µg/l. pH showed a slight increase during these observations (pH 12.4-12.7). Furthermore, concentrations of chromium and molybdenum noticeably decreased at these distinct L/S ratios. The decrease of chromium and molybdenum is suggested to be due to incorporation into the interlayer regions of hydrocalumite (Ca4Al2(OH)12(OH)2∙6H2O), replacing the hydroxide groups, which also explain the increase in pH.

    Trace elements (Cd, Cu, Pb and Zn) from the added ARD were effectively removed from the solution (93-96 %) and were not released until pH dropped below 7. Major mechanism behind the immobilization of trace elements is sorption onto newly formed HAO/HFO.

    Large differences were seen between leaching with different leaching media (distilled water or ARD), why the use of site-specific materials and reagents are crucial in experiments evaluating possible use in field applications.

  • 28.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Reclamation of historical mine waste using alkaline by-products2007Ingår i: Northern Latitudes Mining Reclamation Workshop, Juneau, Alaska, USA, 15-17 May, 2007, 2007, s. 10 pages-Konferensbidrag (Refereegranskat)
  • 29.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Treatment of acidic and neutral metal-laden mine waters with bone meal filters2012Ingår i: Mine Water and the Environment / [ed] McCullough, C.D., Lund, M.A. and Wyse, L, International Mine Water Association (IMWA) , 2012, s. 643-650Konferensbidrag (Refereegranskat)
  • 30.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Treatment of Acidic and Neutral Metal-Laden Mine Waters with Bone Meal Filters2013Ingår i: Mine Water and the Environment, ISSN 1025-9112, E-ISSN 1616-1068, Vol. 32, nr 4, s. 293-301Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Bone meal was used to treat two different mine waters: acidic (pH 4.5) mine water containing high concentrations of Fe and Al and neutral/slightly alkaline (pH 7) mine water. Original primary contaminants in both waters were Pb and Zn. The contaminants were dissolved in the acidic mine water and mostly suspended in the neutral mine water. Flow through the filter treating the acidic mine water was relatively low (0.1 L/min), but increased towards the end of the test period. Removal of Pb and Cu was very good in the acidic mine water (around 80 %); removal of Zn was slightly less (60 %) due to the final pH (approximate to 6-6.5). Flow through the filter treating the neutral mine water was initially significantly higher (5 L/min) and the removal of Pb and Zn was less compared to the acidic mine water (50 % for Pb and 35 % for Zn). The major reason for the difference in metal removal in the two mine waters was the difference in Fe and Al sorption sites, flow rate, and pH; in order for the bone meal to dissolve and form metal phosphate, the pH has to be <7.

  • 31.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kumla, Sverige.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Allard, Bert
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    On the neutralisation of ARD and acid generating waste rock by different alkalinity sources: carbonate and/or hydroxide2010Ingår i: Mine water & innovative thinking: proceedings 2010 / [ed] Wolkersdorfer, C. and Freund, A., Nova Scotia, Canada: Cape Breton University Press , 2010, s. 263-266Konferensbidrag (Refereegranskat)
    Abstract [en]

    Six alkaline waste materials were tested for their neutralising capacity and metal immobilisation ability as amendments to a weathered waste rock. Two of the materials were of carbonate-type: lime mud (LM) and green liquor dreg (GLD) and four were of hydroxide-type: lime kiln dust (LKD), LD-slag (LD), carbonated fly ash (CFA) and a fresh fly ash (FFA). pH achieved by carbonate and ARD reactions (approximately 6) is too low to ensure quantitative sorption of e.g. Zn and Cd. Hydroxide neutralisation reactions however result in higher pH, but lower alkalinity.

  • 32.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Alkaline by-products as amendments for stabilization and neutralization of oxidized sulphidic mine waste deposits2010Ingår i: 34th British Columbia Mine Reclamation & 35th CLRA/ACRSD National Conference, 2010, s. 10 pages-Konferensbidrag (Refereegranskat)
    Abstract [en]

    Stabilization of oxidized sulphidic mine waste deposits with alkaline by-products could be a way of controlling ARD. Mixtures of alkaline by-products (10% by volume) and oxidized waste rock have been studied during six months in 30 L experimental drums. Alkaline by-products are: lime mud (LM), green liquor dreg (GLD), lime kiln dust (LKD), LD slag (LD), water work granules (WWG), carbonized fly ash (FAE) and fresh fly ash (FAF). The experiments are fed with water once a week to imitate natural precipitation.

    pH of the reference (no alkaline amendment) is below 3 and trace metal concentrations are 2000 mg/l, 4 mg/l and 1 mg/l for Zn, Cd and Pb respectively. LKD, LM and LD amended systems (pH 6.7-7.5) are the most efficient for Cd- and Zn-removal (reduction at least 99 % compared to the reference), while GLD (tap pH 6.5) is the most efficient for Pb-removal (99 % reduction compared to the reference). FAE amended system only reaches pH around 5 and accordingly trace metal reduction is rather low. Geochemical simulations using PHREEQC indicate equilibrium with otavite and smithsonite in the WWG and GLD systems, whereas cerrusite is at equilibrium in the LKD, WWG and GLD systems.

  • 33.
    Sartz, Lotta
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Paper mill by-products and fly ash as amendments to oxidized waste rock: neutralization and trace metal reduction in a meso-scale field studyManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Remediation of oxidized mine waste is often hampered by the risk of reductive dissolution of ferric iron phases and the resulting release of trace elements. In order to partly avoid this problem the oxidized mine waste can be amended with an alkaline material. In this meso-scale experiment with 7 different amended systems and a control an oxidized waste rock was mixed with several alkaline by-products and leachates were collected for 44 months. Results show that pH in the amended systems increased between 1.1 and 2.2 pH units compared to the untreated reference (pH 4.4). The increase in pH resulted in a significant decrease in trace element concentrations, averaging a concentration reduction around 97 %. Sorption was probably the main reduction mechanism.

    Flow rate measurements in the different systems showed a strong correlation between pH and the flow rate. It was concluded that the type of alkaline material and the number of alkaline layers were of less importance than the flow rate when it came to quality of the leachates. However, fly ashes were found in all the best performing systems. Longer residence time clearly improves the quality of the leachates. When it comes to comparison of the different systems it seems that systems containing fly ashes performed best. Least effective systems contained green liquor dregs and amendments with too little fly ash. It is clear that alkaline materials can be used in order to reduce the leaching of trace elements from historical mine waste deposits.

  • 34.
    Sartz, Lotta
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik. Bergskraft Bergslagen AB.
    Bäckström, Mattias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Akademin för juridik, psykologi och socialt arbete.
    Allard, Bert
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Effect of pH and time on the release of vanadium from LD -slag2009Konferensbidrag (Refereegranskat)
  • 35.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Allard, Bert
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    From bench to field: A stepwise method towards full scale remediation of historic mine sites2009Ingår i: 8th International Conference on Acid Rock Drainage (ICARD) and Securing the Future: Mining, Metals & the Environment in a Sustainable Society 2009, 2009, s. 1207-1216Konferensbidrag (Refereegranskat)
  • 36.
    Sartz, Lotta
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Allard, Bert
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Leaching of lime kiln dust and LD-slag with ARD in a sequential batch experiment2010Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Treatment of ARD in a reactive barrier or an alkaline filter prior to release to the recipient is a desired and often suggested alternative. Alkaline candidate materials for the purpose that are cheap are by-products such as fly ash, lime kiln dust and different steel slags. An experiment was carried out where two highly alkaline by-products (LD slag and lime kiln dust) were exposed to a real ARD in sequential batch design.

    It was found that the buffering capacity was high enough in both materials in order to neutralize the added ARD even if large portions of the total buffering capacity was washed out during the experiment. Washing out of alkalinity is a greater problem for oxide/hydroxide materials than it is for carbonate dominating materials. Calculations indicated that the buffering capacity in the LKD would last at least until L/S 3 000 while it would last approximately until L/S 1 000 for LD slag. Lack of buffering capacity is thus not the major problem with the materials, but rather the lack of capacity for trace element immobilization. Including sorption onto HFO and HAO and precipitation of different hydroxides and carbonates the already immobilized trace elements from the added ARD started to be remobilized around pH 8. Below pH 8 concentrations increased rapidly due mainly to desorption and was soon found to be higher than in the added ARD.

    Some of the divalent elements (Mg and Mn) were also found to be controlled by their hydroxides at high pH and at circumneutral pH by their carbonates. This results in higher concentrations at lower pH (below 10) since the carbonates are more soluble than the hydroxides.

    It is important to characterize the used alkaline by-products at the expected chemical conditions in order to be able to assess potential trace element leaching (most likely anionic elements such as vanadium and chromium).

  • 37.
    Sartz, Lotta
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Allard, Bert
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Mixing of acid rock drainage with alkaline ash leachates: formation of solid precipitates and pH-buffering2010Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Three metal-rich and acidic mine waters (from Bersbo and Ljusnarsberg, Sweden) were mixed with alkaline fly ash leachates in various proportions, representing a pH-titration. The changes in pH, as well as the loss of metals in solution due to precipitation of solid phases, were followed. Mineral equilibria and changes in pH and alkalinity were simulated with the geochemical code PHREEQC using the MINTEQv4 database, and comparisons between measured and simulated pH-responses were made.

    The formation of solid precipitates corresponded to fairly well-defined pH-buffering regions, reflecting the composition of the mine waters (notably the levels of Fe, Al and Mn). For the mine waters not dominated by iron the precipitation of zinc had a distinct buffering effect at near-neutral pH. The formation of solid magnesium phases (carbonate, as well as hydroxide) was indicated at high pH (above 9), but no formation of solid calcium phases despite high sulfate levels. The phases that precipitate were various amorphous mixtures, mostly of the metals Fe, Al, Mn, Zn and Mg.

    For the iron-rich mine water, pH was poorly simulated with a simple MIX-model, while alkalinity predictions agreed reasonably well with measured data. For the aluminum-rich mine waters the simulated pH-responses agreed well with the measurements.

  • 38.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Allard, Bert
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Mixing of acid rock drainage with alkaline leachates: Formation of solid precipitates and pH-buffering2016Ingår i: Mine Water and the Environment, ISSN 1025-9112, E-ISSN 1616-1068, Vol. 35, nr 1, s. 64-76Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Three metal-rich, acidic mine waters (from Bersbo and Ljusnarsberg, Sweden) were mixed with alkaline fly ash leachates in various proportions, representing a pH titration. Changes in pH and the loss of metals in solution due to precipitation of solid phases were tracked. Mineral equilibria and changes in pH and alkalinity were simulated using the geochemical code PHREEQC and the MINTEQv4 database, and the measured and simulated pH responses were compared. The formation of solid precipitates corresponded to fairly well-defined pH-buffering regions, reflecting the mine water compositions (notably the levels of Fe, Al, and Mn). Zn precipitation had a distinct buffering effect at near-neutral pH for the mine waters not dominated by iron. The formation of solid Mg phases (carbonate, as well as hydroxide) was indicated at high pH (above 9), but not formation of solid Ca phases, despite high sulfate levels. The phases that precipitated were various amorphous mixtures, mostly of the metals Fe, Al, Mn, Zn, and Mg. For the Fe-rich mine water, pH was poorly simulated with a simple MIX model, while alkalinity predictions agreed reasonably well with measured data. For the Al-rich mine waters, the simulated pH responses agreed well with the measurements. In an additional step, geochemical simulations were performed where selected proxy phases for major elements were forced to precipitate; this significantly improved the pH and alkalinity predictions. This approach may be more efficient than performing mixing experiments and titrations.

  • 39.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Allard, Bert
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Stabilisation of acid-generating waste rock with alkaline by-products: Results from a meso-scale experiment2009Ingår i: Securing the Future and 8th ICARD, 2009, s. 10 pages-Konferensbidrag (Refereegranskat)
  • 40.
    Sartz, Lotta
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Allard, Bert
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Strategy for instant neutralisation and metal immobilisation in ARD2010Ingår i: Mine water and innovative thinking: proceedings 2010 / [ed] Christian Wolkersdorfer, Antje Freund, Nova Scotia, Canada: Cape Breton University Press , 2010, s. 267-270Konferensbidrag (Refereegranskat)
    Abstract [en]

    For ARD filters, reactive barriers are often the methods of choice. Some problems are recognised though; iron precipitation cause hydraulic changes and inhibition of neutralising phases. Instead of filter/barrier installation alkalinity is suggested to be added in an aqueous phase (leach beds). Addition of a highly alkaline solution to different ARD results in a rapid, almost instant neutralisation, precipitation of metals (Fe, Al) as well as almost quantitative coprecipitation and sorption of trace metals at near neutral pH. Generation of alkalinity on-site, added to ARD as an aqueous phase, would be a fast and simple ARD treatment method.

  • 41.
    Sartz, Lotta
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Sjöberg, Viktor
    Örebro universitet, Akademin för naturvetenskap och teknik.
    ARD treatment in sequential filter sections: efficiency of different alkaline waste materials2010Ingår i: Mine water and innovative thinking: proceedings 2010 / [ed] Christian Wolkersdorfer, Antje Freund, Nova Scotia, Canada: Cape Breton University Press , 2010, s. 271-274Konferensbidrag (Refereegranskat)
    Abstract [en]

    Six alkaline waste materials are tested as potential filter materials for ARD treatment. The study is an ongoing project since 2.5 years on a mine waste remediation test field in  opparberg, Sweden. The filters (0.5 m3) are operating under field conditions and general parameters (pH, electric conductivity, redox potential (Eh), alkalinity, acidity and sulphate) are measured immediately after sampling in a mobile laboratory. The reactive (alkaline) materials are followed by other filter materials in sequence with non-reactive support materials, to ensure iron/aluminum precipitation and trace metal sorption.

  • 42.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kumla, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sädbom, Stefan
    Bergskraft Bergslagen AB, Kumla, Sweden.
    Allard, Bert
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Alkaline by-products to ameliorate oxidized sulphidic mine waste and ARD2010Ingår i: Proc. EU Mine Drainage Research Exchange Conf. PADRE, June 11, Freiberg, Germany, 2010, s. 1 p-Konferensbidrag (Refereegranskat)
  • 43.
    Sartz, Lotta
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Bäckström, Mattias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Sjöberg, Viktor
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Successive neutralization, precipitation and trace metal immobilization in meso-scale filters for ARD treatmentManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Six alkaline by-products were studied in reactive filters (3×0.4 m3) built on the historic mine site Ljusnarsbergsfältet, Kopparberg, Sweden. Each filter was made out of three connected sections in a sequence (neutralization – oxidation (precipitation) – sorption). Total buffering capacity of the alkaline materials was found to have a minor impact on their respective performances. Other chemical and physical circumstances were more important, e.g. carbonation, iron precipitation and preferential flow path formations. A combination of fresh fly ash and lime mud had similar chemical responses as a carbonated fly ash. These filters were also the worst performers, considering overall trace element immobilizations.

    No particular differences were found between two different passive adsorbents in the oxidation stage, where iron and aluminum were intended to precipitate and act as sorbent phases for other elements: Cu, Zn, Cd, and Pb. In general it was found that highly alkaline materials containing alkalinities as CaO/Ca(OH)2 were superior to materials with carbonate alkalinity.

  • 44.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Sädbom, Stefan
    Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Karlsson, Stefan
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Allard, Bert
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Applicability and suitability of different alkaline by-products in historic mine sites remediation2012Ingår i: 9th International Conference on Acid Rock Drainage (ICARD 2012) / [ed] Price, W.A., Hogan, C. and Tremblay, G., Mine Environment Neutral Drainage ( MEND ) , 2012, s. 682-693Konferensbidrag (Refereegranskat)
  • 45.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kumla, Sweden.
    Hamilton, Ian
    Econova Recycling AB, c/o Alfred Nobel Science Park, Örebro Sweden.
    Macsik, Josef
    Ecoloop AB, Stockholm, Sweden.
    Maurice, Christian
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Luleå, Sweden.
    Sädbom, Stefan
    Bergskraft Bergslagen AB, Kumla, Sweden.
    Westin, Gunnar
    RISE Processum AB, Örnsköldsvik, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kumla, Sweden.
    Green Liquor Dregs from Pulp and Paper Industry used in Mine Waste Management: a Symbiosis Project (GLAD) between two Swedish Base Industries2017Ingår i: Mine Water & Circular Economy / [ed] Wolkersdorfer, C., Sartz, L., Sillanpää, M. and Häkkinen, A, Lappeenranta, Finland: Lappeenranta University of Technology , 2017, Vol. II, s. 862-868Konferensbidrag (Refereegranskat)
    Abstract [en]

    Mining has been and still is an important industry in Sweden. Leaching from sulfidic mining waste is however a serious environmental issue that can bring acidity and metals in solution. Simultaneously, green liquor dreg (GLD) with potential to decrease oxygen transport to the waste and neutralize acid leachate, is generated by the pulp and paper industry and deposited in landfills. The aim of the project is to promote valorisation of GLD, identify hinders and create a database providing information about the material and its variability to enhance establishment of circular economy for the pulp and paper mill waste.

  • 46.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Larsson, Erik
    Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Alkaline treatment of ARD: carbonate and hydroxide alkalinities in sequence2012Ingår i: 9th International Conference on Acid Rock Drainage (ICARD 2012) / [ed] Price, W.A., Hogan, C. and Tremblay, G, Ontario, Kanada: Golder Associates Ltd. , 2012, s. 78-88Konferensbidrag (Refereegranskat)
  • 47.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Larsson, Erik
    Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Sädbom, Stefan
    Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Weathering of waste rock in different climatic conditions: A kinetic freeze/thaw and humidity cell experiment2011Ingår i: Mine water: Managing the challenges: proceedings of the International Mine Water Association Congress 2011 / [ed] Rüde, T.R., Freund, A. and Wolkersdorfer, C., Aachen: RWTH , 2011, s. 453-456Konferensbidrag (Refereegranskat)
    Abstract [en]

    Ferrous and ferric sulphates and (oxy)hydroxides can grow on pyrite surfaces and slow oxidationrates. However, in northern climates, repeated freeze/thaw cycles can cause cracks, channeling and exposureof new surfaces. In the present study, weathering in a repeated freeze/thaw experiment was compared to aregular humidity cell experiment. Introductory results (after 17 weeks) show very small changes in pH for thefreeze/thaw system (pH around 5), while pH in reference and humidity cell systems decreased rapidly thefirst weeks (to around 4). An increase in electrical conductivity, sulphate and major ions was noticed in thetwo latter systems.

  • 48.
    Sartz, Lotta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kumla, Sweden.
    Sädbom, Stefan
    Bergskraft Bergslagen AB, Kumla, Sweden.
    Bäckström, Mattias
    Örebro universitet, Institutionen för naturvetenskap och teknik. Bergskraft Bergslagen AB, Kumla, Sweden.
    Remediation of Historic Waste Rock by Injection of Green Liquor Dregs: Results From a Field Scale Trial, Gladhammar, Southern Sweden2018Ingår i: Mine Water: Risk to Opportunity / [ed] Wolkersdorfer, Ch., Sartz, L., Weber, A., Burgess, J. and Tremblay, G, Pretoria, South Africa: Tshwane University of Technology , 2018, Vol. II, s. 1124-1129Konferensbidrag (Refereegranskat)
    Abstract [en]

    Mining in Gladhammar, southern Sweden started in the 15th century, generating waste rock containing copper, cobalt, and arsenic. During remediation (2011) some waste rock was preserved, due to its geoscienti- c value, and placed on a geomembrane surface. Eventually, it became apparent that it had a substantial environmental impact (pH 3.8, Cu 96 mg/L, Co 21 mg/L). In 2017, green liquor dregs was injected in order to increase pH and decrease trace element mobility. Ten months a er injection pH was 8.3 and concentrations of copper and cobalt 1.3 mg/L and 1.1 mg/L, respectively. Evaluation will continue for at least five years.

  • 49.
    Sjöberg, Viktor
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Sartz, Lotta
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Release of vanadium from LD-slag by exposure to ARD2010Ingår i: Mine water and innovative thinking: proceedings 2010 / [ed] Christian Wolkersdorfer, Antje Freund, Cape Breton University Press , 2010, s. 399-402Konferensbidrag (Refereegranskat)
    Abstract [en]

    In abatement of acid rock drainage (ARD) slag from the Linz-Donawitz steel making process (LD-slag) provides high neutralizing capacity at low cost. A serious drawback for the use of this by-product is its high content of vanadium, which makes it a potential source of toxic vanadium species. The aim of this work was to determine the most common vanadium species, V(IV) and V(V), leached from LD-slag by artificial ARD. Capillary electrophoresis was employed to quantify the species. From the results an initial dominance of V(V) and increasing abundance of V(IV) with increasing artificial ARD L/s ratio was observed.

  • 50.
    Sjöberg, Viktor
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Todd, Kristen
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Sartz, Lotta
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Karlsson, Stefan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Impact of organic carbon in the release of vanadium from LD-slag2011Ingår i: Mine water: managing the challenges: proceedings of the International Mine Water Association Congress 2011 / [ed] Trude R.Rüde, Antje Freund, Christian Wolkersdorfer, Aachen: Rheinisch-Westfälische Technische Hochschule Aachen (RWTH) , 2011, s. 481-484Konferensbidrag (Refereegranskat)
12 1 - 50 av 54
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