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  • 1.
    Otsuki, Akira
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Ecole Nationale Supérieure de Géologie, GeoRessources UMR 7359 CNRS, University of Lorraine, Vandoeuvre-lès-Nancy, France.
    De La Mensbruge, Luc
    Ecole Nationale Supérieure de Géologie, GeoRessources UMR 7359 CNRS, University of Lorraine, Vandoeuvre-lès-Nancy, France.
    King, Andrew
    Synchrotron SOLEIL, Gif-sur-Yvette Cedex, France.
    Serranti, Silvia
    Dipartimento di Ingegneria Chimica Materiali Ambiente, La sapienza - University of Roma, Rome, Italy.
    Fiore, Ludovica
    Dipartimento di Ingegneria Chimica Materiali Ambiente, La sapienza - University of Roma, Rome, Italy.
    Bonifazi, Giuseppe
    Dipartimento di Ingegneria Chimica Materiali Ambiente, La sapienza - University of Roma, Rome, Italy.
    Non-destructive characterization of mechanically processed waste printed circuit boards - particle liberation analysis2020In: Waste Management, ISSN 0956-053X, Vol. 102, p. 510-519Article, review/survey (Refereed)
    Abstract [en]

    This work aimed to develop and propose methods for evaluating the metal degree of liberation to characterize the metal deportment/concentration and liberation/association of mechanically processed waste Printed Circuit Boards (PCBs) that hold the complex and heterogeneity structure and metal distribution/association. Waste PCBs passed through a series of mechanical processing (i.e. comminution, sieving) for the metal recovery were characterized to understand and to evaluate the metal distribution and degree of liberation of the metals in order to optimize the comminution process, avoiding excessive fine particle production. The characterizations were performed at laboratory scale, as well as utilizing large scale experimental facilities, i.e. a portable X-Ray Fluorescence (XRF), micro-XRF and Synchrotron X-Ray Tomography. The proposed methods confirmed that metal liberation was very high in the fine size fraction (0.125–0.350 mm) while many locked particles were identified in the coarse size fraction (0.350–0.500 mm). Such results were analyzed and were discussed in order to better understand metal deportment/concentration behaviors. The advantages and disadvantages related to the different characterization approaches were identified and discussed in this paper, as well as their methodological developments in a waste PCBs’ mechanical processing perspective.

  • 2.
    Juanatey, María A. García
    et al.
    Uppsala University, Sweden.
    Hübert, Juliane
    Uppsala University, Sweden.
    Tryggvason, Ari
    Uppsala University, Sweden.
    Juhlin, Christopher
    Uppsala University, Sweden.
    Pedersen, Laust B.
    Bauer, Tobias E.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Dehghannejad, Mahdieh
    Uppsala University, Sweden. Ramboll Sweden..
    2D and 3D MT in the central Skellefte Ore District, northern Sweden2019In: Tectonophysics, ISSN 0040-1951, E-ISSN 1879-3266, Vol. 764, p. 124-138Article in journal (Refereed)
    Abstract [en]

    New broadband magnetotelluric (MT) data have been acquired along two parallel profiles in the central part of the metallogenic Skellefte district in northern Sweden. The data were recorded as part of the Swedish 4D modelling of mineral belts project and cover an area with several economical and sub-economical deposits. The dimensionality and quality of the data were carefully analyzed and new error floors were systematically determined prior to inverse modelling in 2D and 3D. The algorithms used were EMILIA and WSINV3DMT. For the 2D inversion, only the determinant of the impedance tensor was used, while for the 3D inversion all elements were considered. The obtained models fit the inverted data, and image the main regional features. A detailed comparison reveals the superiority of the 3D model, both in model structures and data fit. After assessing the main features in the model, an interpretation is proposed and refined with the support of previous geophysical studies. The most interesting features are large and medium-sized conductors associated with crustal-scale shear zones and faults within the Skellefte Group rocks. These may be depicting a network of fossil pathways for hydrothermal fluid transport and as such, provide new insight into past processes in the area.

  • 3.
    Gao, Jingyu
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Smirnov, Maxim
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Smirnova, Maria
    University of Cologne, Cologne, Germany.
    Egbert, Gary
    Oregon State University, Corvallis, USA.
    3-D DC resistivity forward modeling using the multi-resolution grid2019In: Pure and Applied Geophysics, ISSN 0033-4553, E-ISSN 1420-9136Article in journal (Refereed)
    Abstract [en]

    We implemented a novel multi-resolution grid approach to direct current resistivity (DCR) modeling in 3-D. The multi-resolution grid was initially developed to solve the electromagnetic forward problem and helped to improve the modeling efficiency. In the DCR forward problem, the distribution of the electric potentials in the subsurface is estimated. We consider finite-difference staggered grid discretization, which requires fine grid resolution to accurately model electric potentials around the current electrodes and complex model geometries near the surface. Since the potential variations attenuate with depth, the grid resolution can be decreased correspondingly. The conventional staggered grid fixes the horizontal grid resolution that extends to all layers. This leads to over-discretization and therefore unnecessary high computational costs (time and memory). The non-conformal multi-resolution grid allows the refinement or roughening for the grid’s horizontal resolution with depth, resulting in a substantial reduction of the degrees of freedom, and subsequently, computational requirements. In our implementation, the coefficient matrix maintains its symmetry, which is beneficial for using the iterative solvers and solving the adjoint problem in inversion. Through comparison with the staggered grid, we have found that the multi-resolution grid can significantly improve the modeling efficiency without compromising the accuracy. Therefore, the multi-resolution grid allows modeling with finer horizontal resolutions at lower computational costs, which is essential for accurate representation of the complex structures. Consequently, the inversion based on our modeling approach will be more efficient and accurate.

  • 4.
    Morgan-Sagastume, Fernando
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Veolia Water Technologies AB.
    Valentino, Francesco
    Department of Chemistry, Sapienza University of Rome.
    Hjort, Markus
    Veolia Water Technologies AB.
    Zanaroli, Giulio
    Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna.
    Majone, Mauro
    Department of Chemistry, Sapienza University of Rome.
    Werker, Alan G.
    Veolia Water Technologies AB .
    Acclimation Process for Enhancing Polyhydroxyalkanoate Accumulation in Activated-Sludge Biomass2019In: Waste and Biomass Valorization, ISSN 1877-2641, E-ISSN 1877-265X, Vol. 10, no 4, p. 1065-1082Article in journal (Refereed)
    Abstract [en]

    A strategy was evaluated for conditioning activated sludge biomass to a new substrate whereby the polyhydroxyalkanoate (PHA) accumulation capacity of the biomass was enhanced based on a series of aerobic feast–famine acclimation cycles applied prior to PHA accumulation. Different biomass types enriched during the treatment of municipal wastewater at laboratory, pilot, and full scales were exposed to aerobic feast–famine acclimation cycles at different feast-to-famine ratios with an acetate–propionate mixture (laboratory scale), acetate (pilot scale), and fermented waste–sludge centrate (pilot scale). A sevenfold increase in specific PHA storage rates and 20% increase in substrate utilization rates were observed during acclimation cycles (laboratory acetate–propionate). Biomass acclimation led to more than doubling of the specific substrate utilization rates, PHA storage rates, biomass PHA contents, and specific PHA productivities (per initial biomass) during PHA accumulation. The biomass PHA contents were found to increase due to acclimation from 0.19 to 0.34 (laboratory acetate–propionate), 0.39 to 0.46 (pilot acetate) and 0.19 to 0.25 gPHA/gVSS (pilot centrate). A similar bacterial community structure during acclimation indicated that a physiological rather than a genotypic adaptation occurred in the biomass. The physiological state of the biomass at the start of PHA accumulation was deemed significant in the subsequent PHA-accumulation performance. Positive acclimation trends can be monitored by measuring the relative increase in feast substrate utilization or respiration rates with respect to those of the first acclimation cycle.

  • 5.
    Entwistle, Jane A.
    et al.
    Department of Geography and Environmental Sciences, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST, UK.
    Amaibi, Patrick M.
    Department of Applied Sciences, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST, UK.
    Dean, John R.
    Department of Applied Sciences, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST, UK.
    Deary, Michael E.
    Department of Geography and Environmental Sciences, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST, UK.
    Medock, Daniel
    Toxicology Department, Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, Oxon OX11 0RQ, UK.
    Morton, Jackie
    Health and Safety Executive, Harpur Hill, Buxton SK17 9JN, UK.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. ALS Global Scandinavia, Aurorum 10, 977 75 Luleå, Sweden.
    Bramwell, Lindsay
    Institute of Health and Society, Medical Faculty, Newcastle University, Newcastle upon Tyne NE2 4AX, UK.
    An apple a day? Assessing gardeners' lead exposure in urban agriculture sites to improve the derivation of soil assessment criteria2019In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 122, p. 130-141Article in journal (Refereed)
    Abstract [en]

    Globally, many of our urban agriculture sites (UAS) contain high levels of lead (Pb), a contaminant of toxicological concern to humans. To improve the derivation of soil assessment criteria at UAS, and avoid inappropriate closure of these valuable community spaces, we sampled nearly 280 paired soil and crop samples across 31 UAS gardens. This sampling was coupled with an exposure and food frequency questionnaire and participants blood Pb levels (BLL), (43 gardeners and 29 non-gardening neighbours). In 98% of the sampled soils, Pb concentrations were above the current UK soil guideline for UAS (80 mg/kg), however despite the high soil Pb (geometric mean: 324 mg/kg), and high soil bioaccessible Pb (geometric mean: 58.7%), all participants BLL were <4.1 μg/dL (range: 0.6–4.1 μg/dL). Indeed, there was no statistically significant difference between the BLL of the UAS gardeners and those of their non-gardening neighbours (p = 0.569).

    Pb uptake, however, varied with crop type and our study highlights the suitability of certain crops for growing at UAS with elevated Pb (e.g. tubers, shrub and tree fruit), whilst limiting the consumption of others (selected root vegetables, such as rhubarb, beetroot, parsnips and carrots, with observed Pb concentrations > 0.1 mg/kg FW).

    The importance of defining the exposure scenario of a specific sub-population (i.e. UAS gardeners) is highlighted. Our preferred models predict site specific assessment criteria (SSAC) of 722–1634 mg/kg. We found fruit and vegetable consumption rates by all participants, and not just the UAS gardeners, to be considerably higher than those currently used to derive the UK's category 4 screening levels (C4SLs). Furthermore, the soil to plant concentration factors (SPCFs) used to derive the UAS C4SL significantly over predict Pb uptake. Our study indicates it may be appropriate to develop a distinct exposure dataset for UAS. In particular we recommend the derivation of SPCFs that are reflective of urban soils, both in terms of the range of soil Pb concentrations typically observed, but also the sources (and hence human oral bioaccessibility and plant-availability) of this Pb.

  • 6.
    Jansson, Nils
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Allen, Rodney L.
    Volcanic Resources AB.
    Skogsmo, Göran
    Björka mineral AB.
    Vorbrodt, Nils
    Björka mineral AB.
    Bäckström, Mattias
    Björka mineral AB.
    An updated genetic model for metamorphosed and deformed, c. 1.89 Ga magnesian Zn-Pb-Ag skarn deposits, Sala area, Bergslagen, Sweden2019In: Proceedings of the 15th SGA Biennial Meeting, 27-30 August 2019, Glasgow, Scotland, Life with Ore Deposits on Earth, 2019, Vol. 1, p. 166-169Conference paper (Refereed)
    Abstract [en]

    This contribution presents an updated view on the genesis of stratabound Zn-Pb-Ag mineralization in the Sala area, Bergslagen, Sweden. Integrated legacy and new geological, geochemical and geophysical data reveal that the deposits are hosted by a complex array of magnesian skarn-altered zones in dolomitic marble. These mineralized zones parallel early faults and metavolcanic interbeds in the host marble, and converge downwards in the stratigraphy adjacent to a 1.89 Ga calc-alkaline granite-granodiorite batholith. Prograde alteration involved formation of early barren ferroan diopside- and forsterite-bearing skarns. Mineralization is mainly associated with subsequent alteration to tremolite, chlorite, serpentine, magnetite and calcite. The hydrous associations overlap mineralogically with assemblages formed during subsequent greenschist facies regional metamorphism between 1.87 Ga and 1.8 Ga. However, ferroan diopside and forsterite are unique to the alteration system, and indicate mineralization in conjunction with an early, high T, metasomatic alteration event at 1.89 Ga. The Sala deposits can be classified as Zn skarn deposits, albeit atypical in the magnesian nature of the skarns and the lack of minerals with essential Mn. The Fe and Mn content in magnesian silicates and carbonates is however sufficient to induce clear enrichment haloes of these elements around the deposits. The magnesian nature of the skarns probably reflect formation in a shallow marine continental backarc tectonic setting, and an importance of seawater in early pre-skarn alteration stages, such as dolomitization.

  • 7.
    Bauer, Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Andersson, Joel B.H.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kampmann, Tobias Christoph
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Analysis of data from Unmanned Aerial Systems (UAS) in a Virtual Reality environment2019In: Proceedings of the Visual3D conference / [ed] Tobias C. Kampmann, 2019, p. 19-19Conference paper (Refereed)
    Abstract [en]

    The use of Unmanned Aerial Systems (UAS) is getting increasingly popular for many different types of applications. The field of geology is slowly catching up resulting in new and innovative UAS solutions for various kinds of airborne measurement techniques. These techniques comprise a wide range of geophysical and remote sensing methods used to investigate the sub-surface. At Luleå University of Technology two different types of UAS are used in combination with a Virtual Reality environment in order to analyze geological structures and related ore deposits and mineralizations. The two UAS comprise a) a custom made quadrocopter (HUGIN) with a pay load of approx. 3.5 kg and an operational time of 5 times (batteries) maximum 35 minutes depending on payload, ambient temperatures and wind speed; and b) a foldable DJI Mavic Pro with an operational time of 3 times 30 minutes. The HUGIN system can be operated with a high-resolution optical camera for photogrammetry surveys and a 3-axial fluxgate magnetometer for measuring magnetic anomalies within bedrock and ultimately delineating geological structures. The system is highly flexible and a thermal camera is currently added to the system in order detect water fluxes in relation to geological structures or exothermal mineral processes. The DJI system is equipped with an optical camera for photogrammetric surveying and is a highly valuable tool in remote areas due to its lightweight and compact construction.Data acquired from both UAS is subsequently analysed in a Virtual Reality lab utilizing a 6m wide screen with active stereo functions. Photogrammetry data is first processed using the Aigsoft software package following a Structure for Motion (SfM) workflow where dense point cloud models and subsequently meshed and textured 3D surface models are produced. These models are then converted and transferred to the GeoVisionary software package that allows visualization of models in stereo 3D view. This allows digitizing geological structures such as foliation, fractures, and faults among others in an immersive 3D environment and provides an efficient tool complimentary to traditional field mapping. In particular, this makes it possible to capture and analyse data from hardly accessible and dangerous areas such as rock faces in open pits. Another complimentary method of data analysis comprises SCAT analysis of the meshed surfaces using the MOVE software package.

  • 8.
    Guntoro, Pratama Istiadi
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Tiu, Glacialle
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Lund, Cecilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Rosenkranz, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Application of machine learning techniques in mineral phase segmentation for X-ray microcomputed tomography (µCT) data2019In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 142, article id 105882Article in journal (Refereed)
    Abstract [en]

    X-ray microcomputed tomography (µCT) offers a non-destructive three-dimensional analysis of ores but its application in mineralogical analysis and mineral segmentation is relatively limited. In this study, the application of machine learning techniques for segmenting mineral phases in a µCT dataset is presented. Various techniques were implemented, including unsupervised classification as well as grayscale-based and feature-based supervised classification. A feature matching method was used to register the back-scattered electron (BSE) mineral map to its corresponding µCT slice, allowing automatic annotation of minerals in the µCT slice to create training data for the classifiers. Unsupervised classification produced satisfactory results in terms of segmenting between amphibole, plagioclase, and sulfide phases. However, the technique was not able to differentiate between sulfide phases in the case of chalcopyrite and pyrite. Using supervised classification, around 50–60% of the chalcopyrite and 97–99% of pyrite were correctly identified. Feature based classification was found to have a poorer sensitivity to chalcopyrite, but produced a better result in segmenting between the mineral grains, as it operates based on voxel regions instead of individual voxels. The mineralogical results from the 3D µCT data showed considerable difference compared to the BSE mineral map, indicating stereological error exhibited in the latter analysis. The main limitation of this approach lies in the dataset itself, in which there was a significant overlap in grayscale values between chalcopyrite and pyrite, therefore highly limiting the classifier accuracy.

  • 9.
    Boesen, Amanda H.
    et al.
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway.
    Thiel, Alexandra
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway.
    Fuchs, Boris
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway.
    Evans, Alina L.
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway.
    Bertelsen, Mads F.
    Center for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg, Denmark.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. ALS Scandinavia AB.
    Arnemo, Jon M.
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway. Department of Wildlife, Fish and Environmental Studies, Faculty of Forest Sciences, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Assessment of the LeadCare® Plus for Use on Scandinavian Brown Bears (Ursus arctos)2019In: Frontiers in Veterinary Science, ISSN 2297-1769, Vol. 6, article id 285Article in journal (Refereed)
    Abstract [en]

    Lead (Pb) exposure is associated with adverse health effects in both humans and wildlife. Blood lead levels (BLL) of sentinel wildlife species can be used to monitor environmental lead exposure and ecosystem health. BLL analyzers, such as the LeadCare (R), are validated for use in humans, assessed for use in some avian species and cattle, and are increasingly being used on wildlife to monitor lead exposure. The LeadCare (R) analyzers use a technique called anodic stripping voltammetry (ASV). Species-specific conversion equations have been proposed to approximate the levels found with gold standard measuring methods such as inductively coupled plasma mass spectrometry (ICP-MS) because the ASV method has been shown to underestimate BLL in some species. In this study we assessed the LeadCare (R) Plus (LCP) for use on Scandinavian brown bears (Ursus arctos). LCP measurements were correlated with ICP-MS with a Bland-Altman analyzed bias of 16.3-22.5%, showing a consistent overestimation of BLL analyzed with LCP. Based on this analysis we provide conversion equations for calculating ICP-MS BLL based on the LCP results in Scandinavian brown bears. Our study shows that the LeadCare (R) Plus can be used for monitoring of lead exposure by approximating gold standard levels using conversion equations. This enables comparison with other gold standard measured BLL within the observed range of this study (38.20-174.00 mu g/L). Our study also found that Scandinavian brown bears are highly exposed to environmental lead.

  • 10.
    Warlo, Mathis
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Wanhainen, Christina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bark, Glenn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Butcher, Alan
    Geological Survey of Finland/Geologian tutkimuskeskus, Espoo, Finland.
    McElroy, Iris
    Boliden AB.
    Brising, Dominique
    Boliden AB.
    Rollinson, Gavyn
    Camborne School of Mines, University of Exeter.
    Automated quantitative mineralogy optimized for simultaneous detection of (precious/critical) rare metals and base metals in a production-focused environment2019In: Minerals, ISSN 2075-163X, E-ISSN 2075-163X, Vol. 9, no 7, article id 440Article in journal (Refereed)
    Abstract [en]

    Automated Scanning Electron Microscopy (ASEM) systems are applied in the mining industry to quantify the mineralogy of the ore feed and products. With society pushing towards sustainable mining, this quantification should be comprehensive and include trace minerals since they are often either deleterious or potential by-products. Systems like QEMSCAN® offer a mode for trace mineral analysis (TMS mode); However, it is unsuitable when all phases require analysis. Here, we investigate the potential of detecting micron-sized trace minerals in fieldscan mode using the QEMSCAN® system with analytical settings in line with the mining industry. For quality comparison, analysis was performed at a mining company and a research institution. This novel approach was done in full collaboration with both parties. Results show that the resolution of trace minerals at or below the scan resolution is difficult and not always reliable due to mixed X-ray signals. However, by modification of the species identification protocol (SIP), quantification is achievable, although verification by SEM-EDS is recommended. As an add-on to routine quantitative analysis focused on major ore minerals, this method can produce quantitative data and information on mineral association for trace minerals of precious and critical metals which may be potential by-products in a mining operation

  • 11.
    Liu, Jian-li
    et al.
    University of Science and Technology Beijing, Beijing, China.
    Yao, Jun
    China University of Geosciences (Beijing), China.
    Wang, Fei
    University of Science and Technology Beijing, Beijing, China.
    Min, Ning
    China University of Geosciences (Beijing), China.
    Gu, Ji-hai
    China University of Geosciences (Beijing), China.
    Li, Zi-fu
    University of Science and Technology Beijing, Beijing, China.
    Sunahara, Geoffrey
    China University of Geosciences (Beijing), China; McGill University, Montreal, Quebec,Canada.
    Duran, Robert
    China University of Geosciences (Beijing), China; Université de Pau et des Pays de l’Adour, Pau Cedex, France.
    Solevic-Knudsen, Tatjana
    University of Belgrade, Belgrade, Serbia.
    Hudson-Edwards, Karen A.
    University of Exeter, Penryn, Cornwall, UK.
    Alakangas, Lena
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bacterial diversity in typical abandoned multi-contaminated nonferrous metal(loid) tailings during natural attenuation2019In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 274, p. 98-107Article in journal (Refereed)
    Abstract [en]

    Abandoned nonferrous metal(loid) tailings sites are anthropogenic, and represent unique and extreme ecological niches for microbial communities. Tailings contain elevated and toxic content of metal(loid)s that had negative effects on local human health and regional ecosystems. Microbial communities in these typical tailings undergoing natural attenuation are often very poorly examined. The diversity and inferred functions of bacterial communities were examined at seven nonferrous metal(loid) tailings sites in Guangxi (China), which were abandoned between 3 and 31 years ago. The acidity of the tailings sites rose over 31 years of site inactivity. Desulfurivibrio, which were always coupled with sulfur/sulfide oxidation to dissimilate the reduction of nitrate/nitrite, were specific in tailings with 3 years abandonment. However, genus beneficial to plant growth (Rhizobium), and iron/sulfur-oxidizing bacteria and metal(loid)-related genera (Acidiferrobacter and Acidithiobacillus) were specific within tailings abandoned for 23 years or more. The increased abundance of acid-generating iron/sulfur-oxidizing and metal(loid)-related bacteria and specific bacterial communities during the natural attenuation could provide new insights for understanding microbial ecosystem functioning in mine tailings. OTUs related to Sulfuriferula, Bacillus, Sulfurifustis, Gaiella, and Thiobacillus genera were the main contributors differentiating the bacterial communities between the different tailing sites. Multiple correlation analyses between bacterial communities and geochemical parameters indicated that pH, TOC, TN, As, Pb, and Cu were the main drivers influencing the bacterial community structures. PICRUSt functional exploration revealed that the main functions were related to DNA repair and recombination, important functions for bacterial adaptation to cope with the multi-contamination of tailings. Such information provides new insights to guide future metagenomic studies for the identification of key functions beyond metal-transformation/resistance. As well, our results offers novel outlooks for the management of bacterial communities during natural attenuation of multi-contaminated nonferrous metal(loid) tailings sites. 

  • 12.
    Luth, Stefan
    et al.
    Department of Mineral Resources, Geological Survey of Sweden, Sweden.
    Sahlström, Fredrik
    Department of Earth Sciences, Uppsala University, Sweden.
    Jansson, Nils
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Jönberger, Johan
    Department of Mineral Resources, Geological Survey of Sweden, Sweden.
    Sädbom, Stefan
    Lovisagruvan AB.
    Landström, Erik
    Orexplore AB.
    Bergqvist, Mikael
    Orexplore AB.
    Arvanitidis, Nikolaos
    Department of Mineral Resources, Geological Survey of Sweden, Sweden.
    Arvidsson, Ronald
    Department of Mineral Resources, Geological Survey of Sweden, Sweden.
    Building 3D geomodels using XRF-XRT-generated drillcore data: The Lovisa-Håkansboda base metal- and Stråssa-Blanka iron deposits in Bergslagen, Sweden2019In: Life with Ore Deposits on Earth: Proceedings of the 15th SGA Biennial Meeting 2019, Glasgow, Scotland, 2019, Vol. 3, s. 1282-1485, 2019Conference paper (Refereed)
    Abstract [en]

    3D geological models based on data fromgeological field observations, magnetic airborne surveys and combined XRF-XRT scanning of drill core arepresented for the Lovisa-Håkansboda and the Stråssa-Blanka mineral systems (1.9 - 1.8 Ga). At first, the 3D architecture of several deposits was derived primarilyfrom surface data and mine-level maps. Secondly, geochemical and structural constrains from drill corescanning (XRF-XRT) were used to refine the modelslocally to a detailed, in-mine scale. The constructed models were then placed in a regional context providingvaluable insight on the area’s local and regional deformation pattern. All modelled deposits are plunging 50-60° towards the south-southeast reflecting D2 deformation (vertical shearing) during NW-SE-directed shortening and are locally overprinted by D3 (lateral shearing) during N-S-directed shortening.

  • 13.
    Sarlus, Zimer
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Luleå University of Technology.
    Martinsson, Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bauer, Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Wanhainen, Christina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Andersson, Joel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Nordin, Roger
    Boliden Mineral AB.
    Character and tectonic setting of plutonic rocks in the Gällivare area, northern Norrbotten, Sweden2019In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 141, no 1, p. 1-20Article in journal (Refereed)
    Abstract [en]

    Petrographical and lithogeochemical investigations in combination with mapping in the Gällivare area, northern Norrbotten, Sweden, have led to the identification of several igneous intrusive rock types. These include: (1) ultramafic-mafic complexes, (2) mafic-intermediate rocks, (3) dolerites and (4) felsic plutons. The ultramafic-mafic rocks include the ca. 1.88 Ga Dundret complex and ca. 1.80 Ga Vassaravaara complex. The Dundret complex has tholeiitic to calc-alkaline affinity, shows a primitive mineral content and was formed in an extensional tectonic setting. The Vassaravaara complex has a similar chemical signature as the Dundret complex. The mafic-intermediate plutons vary in composition from gabbro to diorite. The chemical signature of the dioritic rocks indicate formation in a volcanic arc setting. Dolerites occur as solitary dikes and have calc-alkaline affinity. The felsic plutons include granite and syenite of ca. 1.88, 1.80 and 1.78 Ga age. The felsic plutons have calc-alkaline to shoshonitic affinity and mostly show a metaluminous I-type character. Results indicate subduction at 1.90 Ga resulting in a volcanic arc system, and including extensional events generating back-arc environments leading to mafic, intermediate and felsic magmatism in the Gällivare area. Subduction at 1.80 Ga is suggested to have caused a similar process generating mafic and felsic magmatic rocks in the same area. A subsequent collision event finally generated 1.78 Ga granitic rocks.

  • 14.
    Trublet, Mylene
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Scukins, Edvards
    Aeronautics, Department of Flight Data and Navigation, SAAB, Linköping, Sweden.
    Carabante, Ivan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Rusanova-Naydenova, Daniela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Competitive Sorption of Metal Ions on Titanium Phosphate Sorbent(TiP1) in Fixed-Bed Columns: A Closed-Mine Waters Study2019In: ACS Sustainable Chemistry & Engineering, ISSN 2168-0485, Vol. 7, no 9, p. 8145-8154Article in journal (Refereed)
    Abstract [en]

    Sorptionfixed-bed column experiments were performed using atitanium phosphate ion-exchanger composed of−H2PO4units [TiO(OH)(H2PO4)·H2O]. Model mine water containingfive divalent metal ions (Cu2+,Zn2+,Mn2+,Ni2+,and Co2+) and a few closed-mine water samples were treated to evaluate the sorptionpreference of the material. For thefirst time, dynamic ion-exchange capacities(estimated to be between 3.2 and 4.2 mequiv g−1) and static ion-exchange uptakes(calculated to be between 3.1 and 3.5 mequiv g−1) were obtained for the same TiP1sorbent and data were discussed in terms of sorption behavior. It was found thatsorption processes on TiP1 in model and closed-mine waters during a columnexperiment could be accurately predicted from the corresponding batch experiment(including the sorbent’s capacities in different types of waters). A competitivesorption phenomenon in favor of Cu2+on TiP1 was established for all cases, pointingtoward the possibility of isolating pure copper concentrate from closed-mine waters.The relatively high amounts of calcium and magnesium ions present in mine waters did not appear to considerably affect theselectivity of TiP1 material. Exploratory experiments for sorbent regeneration and desorption using a low concentration of nitricacid were demonstrated.

  • 15.
    Billström, K.
    et al.
    Dep. of Geological Sciences, Swedish Museum of Natural History, Stockholm, Sweden.
    Evins, P.
    WPS Consulting Group, Stockholm, Sweden.
    Martinsson, Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Jeon, H.
    Dep. of Geological Sciences, Swedish Museum of Natural History, Stockholm, Sweden.
    Weihed, Pär
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Conflicting zircon vs. titanite U-Pb age systematics and the deposition of the host volcanic sequence to Kiruna-type and IOCG deposits in northern Sweden, Fennoscandian shield2019In: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433, Vol. 321, p. 123-133Article in journal (Refereed)
    Abstract [en]

    The Northern Norrbotten region, and in particular the Kiruna area, hosts a number of large apatite iron oxide deposits (e.g. the huge Kiirunavaara ore) of significant economic importance. Age data from rock lithologies hosting these ores, represented by metamorphosed rocks of the Porphyrite and Kiirunavaara Groups, are complex to interpret. This is illustrated by (LA-ICP-MS) data for titanite, and to some extent for rutile, which scatter considerably yielding ages within a span from ca. 2.1 Ga to 1.7 Ga. These analysed hydrothermal minerals, characterized by complex BSE images revealing darker and brighter zones, are located in ore zones and associated with e.g. strong scapolitisation, albitisation and actinolitisation. Previous (TIMS) zircon ages of host rocks, on the other hand, define a more narrower age interval between ca. 1900 and 1870 Ma, and this is supported by new U-Pb zircon results presented here. Furthermore, one coherent set of SIMS data for titanite from the Luossavaara ore favour that crystallization took place at ca 1.88 Ga, although laser ICP data from the same locality are much more complex. An implication arising from published pre-1.9 Ga laser ablation ages for titanites is that the emplacement of host rocks started already at around 2.1 Ga. As the depositional time of these rocks is crucial for the understanding of the overall crustal formation in northern Norrbotten, additional rocks were selected for age dating. New zircon age data (LA-ICP-MS and SIMS) give support to a scenario where host rocks to ores started to develop at around 1900 Ma and this calls for a re-evaluation of published LA-ICP-MS data of hydrothermal mineral phases.

    Here, we present four models that aim to explain how pre-1.9 Ga titanite ages, believed to have a questionable geological significance, may develop. The principal idea is that ≤2.1 Ga alteration events were not responsible for the crystallization of the hydrothermal minerals, instead it is believed that apparent old age domains carry excess radiogenic lead due to the effect of ≤1.9 Ga hydrothermal processes. Currently, the interpretation of U-Pb isotope data in the study area remains enigmatic, and further radiometric analyses are required.

  • 16.
    Elming, Sten-åke
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Layer, Paul
    Geophysical Institute, University of Alaska Fairbanks.
    Söderlund, Ulf
    Department of Geology, Lund University.
    Cooling history and age of magnetization of a deep intrusion: A new 1.7 Ga key pole and Svecofennian-post Svecofennian APWP for Baltica2019In: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433, Vol. 329, p. 182-194Article in journal (Refereed)
    Abstract [en]

    A paleomagnetic and chronogical study has been performed on the Turinge gabbro-diabase formation and on a cross cutting basic dyke in central Sweden and on the Joulovaara gabbro intrusion in northern Sweden in the Fennoscandian Shield. U-Pb age of baddeleyite and 40Ar/ 39Ar ages of hornblende and biotite reveal a cooling history of the deep gabbro-diabase intrusion in Turinge. The cooling is suggested to have taken place in two stages, one related to the time of intrusion in temperature down to ca 500 °C with a cooling rate up to 46 - 59°/Ma and another at a lower rate of ca 2.9 °C/Ma, which is suggested to be related with uplift. From this cooling history it can be concluded that the magnetization age of the diabase, ca 1695 – 1700 Ma is close to the crystallization age and the 40Ar/39Ar age of hornblende. Applying a similar cooling history for the other studied deep intrusion, the ca 1800 Ma gabbro of Joulovaara gabbro, it is estimated that the magnetization age of the gabbro should be close to that of the U-Pb age of the formation, although the pole of the Joulovaara gabbro is less reliable.

    The cooling history presented here for the Turinge gabbro-diabase has implications for estimations of magnetization ages also for other deep intrusions.

    The new pole (Plat. = 51.6°, Plon. = 220.2°; A95= 4.8°) of the Turinge gabbro-diabase passes most of the reliability criteria and is considered a new key pole for Fennoscandia.

    The Basic dyke that cuts the Turinge gabbro-diabase was here dated at ca 1200 Ma (whole rock, 40Ar/ 39Ar) and the virtual geomagnetic pole calculated from its primary magnetization falls into the expected trend of APWP for Baltica.

    The new Turinge key pole prolong the time of overlapping poles for Fennoscandia, indicating only small movements of the shield between ca. 1870 to 1700 Ma.

  • 17.
    Moradi, M.
    et al.
    Institute of Geophysics, University of Tehran, Tehran, Iran.
    Oskooi, B.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Institute of Geophysics, University of Tehran, Tehran, Iran.
    Pushkarev, P.
    Department of Geophysical Methods of the Earth Crust Exploration, Moscow State University, Moscow, Russia.
    Smirnov, Maxim
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Esmaeili Oghaz, H.
    Natural Iranian Gas Storage Company for Nasr-Abad Area, Tehran, Iran.
    Cooperative inversion of magnetotelluric and seismic data on Shurab diapirs in Central Iran2019In: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 78, no 11, article id 341Article in journal (Refereed)
    Abstract [en]

    Using diapirs as liquid or gas storage structures has increased because salt formations are considered to be extremely impermeable and non-reactive. The process of delineating the diapirs' structures ends in lots of challenges due to their geological complexity. Therefore, the integration of different geophysical methods seems to be necessary to cover different physical characteristics of the diapirs. Shurab diapirs located at the NW of Kashan in Qom basin of Central Iran have been considered as candidates for the first natural gas storages in Iran. A previous 2D seismic survey across the diapir No. 4 of Shurab could not resolve the diapir structure properly and some ambiguities left unresolved. The main goal of this paper is to resolve the structure of diapir No. 4 by employing a cooperative inversion of the seismic and magnetotelluric (MT) data and a comparison with the joint inversion of transverse electric (TE) and transverse magnetic (TM) modes of the MT data. Both inversion schemes show the salt and sedimentary sequences of the stratigraphy of the Qom basin. The sequences of formations from the surface to depth are classified as upper red formation (URF), Qom formation (QF) and lower red formation (LRF). The results also show that the salt body has originated from the LRF. It is worthwhile to mention that the results from the cooperative inversion provide more details especially on the flanks and overhangs of the diapir No. 4. In addition, we have come to the conclusion that the right lateral strike-slip fault system is the most responsible phenomenon for the development of the diapirs in the survey area and the Sen-Sen fault plays a basic role as an elevator to pushing the salt up. The results are in good agreements with the resistivity and density logs of the boreholes. Moreover, the information from the geology, the cooperative inversion results on diapir No. 4, and the coincidence of the path of the Sen-Sen fault with the outcrops of the diapirs No. 1, 3 and 4 obviously provide that the tectonic scenario of the existence for diapir No. 4 could be appointed to the diapirs No. 1 and 3 equally. Another probable consequence would be the under surface continuation of the salt bodies all along the Sen-Sen fault, the verification of which requires regional MT surveys in a regular grid.

  • 18.
    Gong, Zheng
    et al.
    Department of Geology and Geophysics, Yale University.
    Evans, David A.D.
    Department of Geology and Geophysics, Yale University.
    Elming, Sten-åke
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Söderlund, Ulf
    Department of Geology, Lund University.
    Salminen, Johanna M.
    Department of Geosciences and Geography, University of Helsinki.
    Corrigendum to "Paleomagnetism, magnetic anisotropy and U-Pb baddeleyite geochronology of the early Neoproterozoic Blekinge-Dalarna dolerite dykes, Sweden" [Precambrian Res. 317 (2018) 14-32]2019In: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433, Vol. 320, p. 484-485Article in journal (Refereed)
    Abstract [en]

    The authors regret that the incorrect version of Table 3 Fig. 12 appeared in the paper. The corrected Table 3 and Fig. 12 are presented below. In Table 2, Group A mean direction should be Dec = 128.8° Inc = 39.6° α95 = 6.5° and Group B mean direction should be Dec = 127.6° Inc = 65.4° α95 = 9.7°. These changes do not affect any main conclusion of the paper. The authors would like to apologize for any inconvenience caused.

  • 19.
    Roqué Rosell, Josep
    et al.
    Department of Mineralogy, Petrology and Applied Geology, University of Barcelona, Barcelona, Catalunya, Spain.Institut de Nanociència i Nanotecnologia, IN2UB, Facultat de Química, Universitat de Barcelona, Barcelona, Catalunya, Spain..
    Portillo Serra, Joaquim
    Centres Científics i Tecnològics, Universitat de Barcelona, Barcelona, Catalunya, Spain.NanoMEGAS, Brussels, Belgium.
    Aiglsperger, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Plana Ruiz, Sergi
    Institut de Nanociència i Nanotecnologia, IN2UB, Facultat de Química, Universitat de Barcelona, Barcelona, Catalunya, Spain.Institut für Angewandte Geowissenschaften, Technische Universität Darmstadt, Darmstadt, Germany.
    Pratim Das, Partha
    NanoMEGAS, Brussels, Belgium.
    Mendoza Gonzalvez, Joan
    Centres Científics i Tecnològics, Universitat de Barcelona, Barcelona, Catalunya, Spain.
    Trifonov, Trifon
    Centre de Recerca en Ciència i Enginyeria Multiescala de Barcelona, Universitat Politècnica de Catalunya (UPC), Catalunya , Sant Adrià de Besòs, Spain.
    Proenza, Joaquin Antonio
    Department of Mineralogy, Petrology and Applied Geology, University of Barcelona, Barcelona, Catalunya, Spain.Institut de Nanociència i Nanotecnologia, IN2UB, Facultat de Química, Universitat de Barcelona, Barcelona, Catalunya, Spain .
    Crystallographic information data of natural occurring zaccariniite (RhNiAs) obtained by means of precession electron diffraction2019In: Data in Brief, E-ISSN 2352-3409, Vol. 25, article id 104346Article in journal (Refereed)
    Abstract [en]

    The crystal structure of naturally occurring zaccariniite (RhNiAs) has been studied in Transmission Electron Microscopy (TEM) with variable angle Precession Electron Diffraction (PED) techniques. The analysis of the data has yielded tetragonal cell parameters of 3.86, 3.86, 6.77 Å and space group of P4/nmm for the basic structure, and its constituent atom positions for Ni, As and Rh were determined as well by ab-initio structure resolution method. The data is related to “Structural characterization and ab-initio resolution of natural occurring zaccariniite (RhNiAs) by means of Precession Electron Diffraction” (Roqué Rosell et al., 2019).

  • 20.
    Gonçalves, Pedro Pereira
    et al.
    Ecole Nationale Supérieure de Géologie, GeoRessources UMR 7359 CNRS, University of Lorraine, Vandoeuvre-lès-Nancy, France.
    Otsuki, Akira
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Determination of Liberation Degree of Mechanically Processed Waste Printed Circuit Boards by Using the Digital Microscope and SEM-EDS Analysis2019In: Electronics, E-ISSN 2079-9292, Vol. 8, no 10, article id 1202Article in journal (Refereed)
    Abstract [en]

    Characterization of heterogeneous materials, such as particles from mechanically processed waste printed circuit boards, is a challenging task. The majority of characterization methods either give average information or information that is very limited and in a tiny area of specific interest. That said, capturing such heterogeneity is significantly important for any kind of processes. Degree of liberation, indicating how much the target component is liberated from the non-valuable components, is a key property to determine the success of subsequent process for valuable material recovery. This work analyzed the degree of liberation of metals within the products of hammer milling process via the combination of image acquisition and analysis. The digital microscope and a scanning electron microscope (SEM) coupled with the energy dispersive spectroscopy (EDS) were used for image acquisition and elemental mapping, in order to evaluate the selective liberation under different milling conditions (i.e., feed mass, milling time) for different metals (mainly Cu and Al) and particle size fractions. The obtained liberation degree was also modelled and determined the liberation parameters that were compared. The results showed that the degree of liberation significantly depend on the milling conditions and metals we analyzed, and well correlated with the selective metal enrichment behavior. Results between the two methods showed some similarities and discrepancies. The advantages and disadvantages of the above two methods were identified and discussed in the paper, in addition to their methodological developments.

  • 21.
    Benaiges-Fernandez, Robert
    et al.
    Department of Genetics, Microbiology and Statistics, Universitat de Barcelona, Barcelona, Catalonia, Spain. Institute of Environmental Assessment and Water Research (IDAEA, CSIC), Barcelona, Catalonia, Spain.
    Palau, Jordi
    Institute of Environmental Assessment and Water Research (IDAEA, CSIC), Barcelona, Catalonia, Spain. Department of Mineralogy, Petrology and Applied Geology, Universitat de Barcelona, Barcelona, Catalonia, Spain.
    Offeddu, Francesco G.
    Institute of Environmental Assessment and Water Research (IDAEA, CSIC), Barcelona, Catalonia, Spain.
    Cama, Jordi
    Institute of Environmental Assessment and Water Research (IDAEA, CSIC), Barcelona, Catalonia, Spain.
    Urmeneta, Jordi
    Department of Genetics, Microbiology and Statistics, Universitat de Barcelona, Barcelona, Catalonia, Spain. Biodiversity Research Institute (IRBio), Universitat de Barcelona, Barcelona, Catalonia, Spain.
    Soler, Josep M.
    Institute of Environmental Assessment and Water Research (IDAEA, CSIC), Barcelona, Catalonia, Spain.
    Dold, Bernhard
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Sustainable Mining Research & Consultancy EIRL, San Pedro de La Paz, Chile.
    Dissimilatory bioreduction of iron(III) oxides by Shewanella loihica under marine sediment conditions2019In: Marine Environmental Research, ISSN 0141-1136, E-ISSN 1879-0291, Vol. 151, article id 104782Article in journal (Refereed)
    Abstract [en]

    Shewanella is a genus of marine bacteria capable of dissimilatory iron reduction (DIR). In the context of deep-sea mining activities or submarine mine tailings disposal, dissimilatory iron reducing bacteria may play an important role in biogeochemical reactions concerning iron oxides placed on the sea bed. In this study, batch experiments were performed to evaluate the capacity of Shewanella loihica PV-4 to bioreduce different iron oxides (ferrihydrite, magnetite, goethite and hematite) under conditions similar to those in anaerobic sea sediments. Results showed that bioreduction of structural Fe(III) via oxidation of labile organic matter occurred in all these iron oxides. Based on the aqueous Fe (II) released, derived Fe(II)/acetate ratios and bioreduction coefficients seem to be only up to about 4% of the theoretical ones, considering the ideal stoichiometry of the reaction. A loss of aqueous Fe (II) was caused by adsorption and mineral transformation processes. Scanning electron microscope images showed that Shewanella lohica was attached to the Fe(III)-oxide surfaces during bioreduction. Our findings suggest that DIR of Fe(III) oxides from mine waste placed in marine environments could result in adverse ecological impacts such as liberation of trace metals in the environment.

  • 22.
    Conrad, Sarah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Gelting, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Nordblad, Fredrik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Engström, Emma
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. ALS Laboratory Group, ALS Scandinavia AB, Luleå, Sweden .
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. ALS Laboratory Group, ALS Scandinavia AB, Luleå, Sweden .
    Andersson, Per S.
    Department of Geosciences, Swedish Museum of Natural History, Stockholm, Sweden.
    Porcelli, Don
    Department of Earth Sciences, Oxford University, Oxford, UK.
    Gustafsson, Örjan
    Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm, Sweden.
    Semiletov, Igor
    International Arctic Research Center (IARC), University of Alaska, Fairbanks, AK, USA. Pacific Oceanological Institute (POI), Far Eastern Branch of the Russian Academy of Sciences (FEBRAS), Vladivostok, Russia. Tomsk National Research Politechnical University, Arctic Seas Carbon International Research Laboratory, Tomsk, Russia.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea2019In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 16, no 6, p. 1305-1319Article in journal (Refereed)
    Abstract [en]

     Riverine Fe input is the primary Fe source for the ocean. This study is focused on the distribution of Fe along the Lena River freshwater plume in the Laptev Sea using samples from a 600 km long transect in front of the Lena River mouth. Separation of the particulate ( >  0.22 μm), colloidal (0.22 μm–1 kDa), and truly dissolved (<  1 kDa) fractions of Fe was carried out. The total Fe concentrations ranged from 0.2 to 57μM with Fe dominantly as particulate Fe. The loss of >  99% of particulate Fe and about 90% of the colloidal Fe was observed across the shelf, while the truly dissolved phase was almost constant across the Laptev Sea. Thus, the truly dissolved Fe could be an important source of bioavailable Fe for plankton in the central Arctic Ocean, together with the colloidal Fe. Fe-isotope analysis showed that the particulate phase and the sediment below the Lena River freshwater plume had negative δ56Fe values (relative to IRMM-14). The colloidal Fe phase showed negative δ56Fe values close to the river mouth (about -0.20 ‰) and positive δ56Fe values in the outermost stations (about +0.10 ‰). We suggest that the shelf zone acts as a sink for Fe particles and colloids with negative δ56Fe values, representing chemically reactive ferrihydrites. The positive δ56Fe values of the colloidal phase within the outer Lena River freshwater plume might represent Fe oxyhydroxides, which remain in the water column, and will be the predominant δ56Fe composition in the Arctic Ocean.

  • 23.
    Qureshi, Asif
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Quaid-e-Awam University of Engineering, Science and Technology, Nawabshah, Pakistan.
    Maurice, Christian
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Effects of the co-disposal of lignite fly ash and coal mine waste rocks on AMD and leachate quality2019In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 26, no 4, p. 4104-4115Article in journal (Refereed)
    Abstract [en]

    Lignite fly ash (FA) and waste rocks (WRs) were mixed in three different ratios (1:1, 1:3 and 1:5) and studied to compare the effects of adding FA on acid mine drainage generation from coal mining WRs, leachability of elements and the potential occurrence of the secondary minerals. FA mixed with WRs showed significant differences in pH levels compared to previous research. The 1:1 mixture performed best of all the three mixtures in terms of pH and leachability of elements, mainly due to the higher proportion of FA in the mixture. The pH in the 1:1 mixtures varied between 3.3 and 5.1 compared to other mixtures (2.3–3.5). Iron and SO42− leached considerably less from the 1:1 mixture compared to the others, indicating that the oxidation of sulphides was weaker in this mixture. Aluminium leached to a high degree from all mixtures, with concentrations varying from mg L−1 to g L−1. The reason behind this increase is probably the addition of FA which, due to acidic conditions and the composition of the FA, increases the availability of Al. For the same reason, high concentrations of Mn and Zn were also measured. Geochemical modelling indicates that the 1:1 mixture performs better in terms of precipitation of Al3+ minerals, whereas Fe3+ minerals precipitated more in mixtures containing less FA. These results suggest that, with time, the pores could possibly be filled with these secondary minerals and sulphate salts (followed by a decrease in sulphide oxidation), improving the pore water pH and decreasing the leachability of elements. Since grain size plays a crucial role in the reactivity of sulphides, there is a risk that the results from the leaching tests may have been influenced by crushing and milling of the WR samples.

  • 24.
    Hellman, Maria
    et al.
    Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Uppsala, Sweden.
    Bonilla-Rosso, Germán
    Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Uppsala, Sweden.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Juhanson, Jaanis
    Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Uppsala, Sweden.
    Hallin, Sara
    Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Uppsala, Sweden.
    External carbon addition for enhancing denitrification modifies bacterial community composition and affects CH4 and N2O production in sub-arctic mining pond sediments2019In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 158, p. 22-33Article in journal (Refereed)
    Abstract [en]

    Explosives used in mining operations release reactive nitrogen (N) that discharge into surrounding waters. Existing pond systems at mine sites could be used for N removal through denitrification and we investigated capacity in tailings and clarification pond sediments at an iron-ore mine site. Despite differences in microbial community structure in the two ponds, the potential denitrification rates were similar, although carbon limited. Therefore, a microcosm experiment in which we amended sediment from the clarification pond with acetate, cellulose or green algae as possible carbon sources was conducted during 10 weeks under denitrifying conditions. Algae and acetate treatments showed efficient nitrate removal and increased potential denitrification rates, whereas cellulose was not different from the control. Denitrifiers were overall more abundant than bacteria performing dissimilatory nitrate reduction to ammonium (DNRA) or anaerobic ammonium oxidation, although DNRA bacteria increased in the algae treatment and this coincided with accumulation of ammonium. The algae addition also caused higher emissions of methane (CH4) and nitrous oxide (N2O). The bacterial community in this treatment had a large proportion of Bacteroidia, sulfate reducing taxa and bacteria known as fermenters. Functional gene abundances indicated an imbalance between organisms that produce N2O in relation to those that can reduce it, with the algae treatment showing the lowest relative capacity for N2O reduction. These findings show that pond sediments have the potential to contribute to mitigating nitrate levels in water from mining industry, but it is important to consider the type of carbon supply as it affects the community composition, which in turn can lead to uwanted processes and increased greenhouse gas emissions.

  • 25.
    Kampmann, Tobias Christoph
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    de la Varga, Miguel
    RWTH Aachen University.
    Field augmented reality for mineral exploration and mining: An upscaling project2019In: Proceedings of the Visual3D conference 2019, 1–2 October 2019, Uppsala, Sweden: Visualization of 3D/4D models in geosciences, exploration and mining / [ed] Tobias C. Kampmann, Luleå, Sweden: Luleå University of Technology, 2019, p. 52-52Conference paper (Refereed)
    Abstract [en]

    Currently, it is still common practice in the mining industry to display three-dimensional geological, geotechnical and resource data and models as 2D projections on maps, office computers and in written reports. This introduces uncertainties and time inefficiencies regarding data acquisition, interpretation and decision-making. The need in the mining and exploration industry for an improvement of these workflows, as well as for more objective and accurate data, facilitated quality control, as well as more cost-efficient and accurate exploration targeting, has been identified within the VIisual3D network of infrastructure (www.visual3d.info). The FARMIN project aims to develop an augmented reality (AR) solution that visualizes 3D geological data and allows exploration and mining professionals to modify models in the field.We aim to close an identified development gap in the visualization of geological data: the link of gathering data in-situ, updating the models and match virtual and real coordinates while exploring in the field or working in a mine site. We will close this gap in this project, by combining developments on highly efficient 3D geomodelling with state-of-the-art augmented reality (AR) hardware and software, as well as expertise in exploration and mining. The resulting solution will be a game changer for how geologists see and collect data and update their models in the field and in the mine.Augmented reality smartglasses (e.g. Microsoft HoloLens) enable users to interact with high-definition holograms in the real world. Microsoft Hololens, for example, allows users to view, control and interact with 3D content using their hands and voice. Field-compatible augmented reality solutions, including but not limited to Microsoft HoloLens technology, coupled with interactive IoT (internet of things) networks allow not only for the manipulation of holograms in a mock-up size, but even in real scale and location. Similar technology has been successfully established in other industrial sectors such as for construction and maintenance, resulting in increased efficiency, as well as reduced operating costs and working hours.The combination of geomodelling and AR technology will be based on GemPy, an open-source library for implicit geological modelling, developed by RWTH Aachen University, and rexOS, an AR-operating system, developed by Robotic Eyes GmbH. The remaining project consortium consists of two European mining and exploration companies (Boliden Mineral, MATSA Mining), as well as a major consulting company for the mining sector (DMT), a business development company (LTU Business) and a university partner with strong expertise in exploration and ore geology research (Luleå University of Technology). The project will kick off in January 2020 and run for three years. Continuous updates on the project progress will be published via the project homepage, as well as social media channels.

  • 26.
    Karlsson, Teemu
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Geological Survey of Finland GTK.
    Geochemical and mineralogical laboratory methods in waste rock drainage quality prediction2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Harmful substances containing acid or neutral rock drainages (ARD and NRD) are a major challenge related to the management of extractive industry wastes. This issue is particularly related to deposits containing sulphide minerals, which are prone to oxidization under the influence of atmospheric oxygen and water. The drainage quality depends mainly on the mineralogical and chemical composition of the extractive wastes, and especially on the ratio of acid-producing and neutralizing minerals, combined with reactions catalysed by microbes. Since harmful drainages play a major role in the generation of environmental issues for extractive industry, the accurate prediction of the drainage quality is of utmost importance. To design appropriate extractive waste facilities and drainage management, the characterisation of extractive wastes and assessment of the behaviour of the waste material is essential already before the actual mining activities start.

    Several methods have been developed to characterize extractive waste materials and to predict their short and long term behaviour, including e.g. geochemical laboratory tests, static tests and longer term kinetic tests, and geochemical modelling. The characterisation methods for assessing the ARD risk can be divided into static and kinetic tests. Static tests are short term laboratory analyses, usually used for preliminary investigation and screening. Kinetic tests are longer term tests, revealing information on the time scale of drainage events. Commonly used static tests for ARD prediction include acid–base accounting (ABA) tests and the net acid generation (NAG) test. Since acid and neutralisation potential largely depend on the ratio and quality of acid-producing and neutralizing minerals, mineralogical calculations could also be used for ARD prediction. The mobility of potentially harmful substances from extractive waste can be preliminary assessed using different geochemical laboratory tests, including selective extraction and leaching methods. The most commonly used selective extraction method in Finland is the aqua regia (AR) extraction. In addition to some silicates and secondary precipitate minerals, it is intended to dissolve elements bound especially to sulphide phases. A less commonly used method for element mobility prediction is the analysis of the single addition NAG test leachate.

    In this study, several Finnish waste rock sites were investigated and the performances of different preliminary drainage quality test methods evaluated and compared. The assessed acid production potential methods included the ABA test as presented in the standard EN 15875, the single addition NAG test as presented in the AMIRA guidebook, and a SEM mineralogy-based calculation. The assessed methods for element mobility prediction included the single addition NAG test leachate analysis and the AR extraction.

    According to the results, pyrrhotite seems to be the main mineral contributing to acid production, and the silicate minerals the main contributors to the neutralisation potential at the most Finnish waste rock sites. Since silicate minerals appear to have a significant role in ARD prevention, the behaviour of these minerals in mining environment should be more thoroughly investigated. In the investigated Finnish waste rocks, Co, Cr, Cu and Ni often occurred as elevated concentrations, and the most widely abundant harmful elements in the waste rock drainages were Co, Cu, Ni and Zn. The results suggest that an acid production prediction based on SEM mineralogical calculation is at least as accurate as the commonly used static laboratory methods. The AR extraction indicates well which elements might occur as elevated concentrations in the drainage. Also the NAG test leachate analysis performed well in element mobility assessment, but only when the NAG test leachate was sufficiently acidic, the leachate pH being below of 3-6, depending on the element of interest.

  • 27.
    Jansson, Nils
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Allen, Rodney
    Volcanic Resources AB.
    Skogsmo, Göran
    Björka Mineral AB.
    Vorbrodt, Nils
    Björka Mineral AB.
    Bäckström, Mattias
    Björka Mineral AB.
    Geological controls on light dolomite deposits related to polymetallic sulphide deposits, Sala area, Bergslagen, Sweden: insights from whole-rock lithogeochemistry, spectrophotometry and magnetic susceptibility2019In: Geophysical Research Abstracts, 2019, Vol. 21, p. 1-, article id 9056Conference paper (Other academic)
  • 28.
    Jia, Yu
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Department of Environment and Mineral Resources Greenland Institute of Natural Resources Nuuk.
    Stahre, Nanna
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. School of Science and Technology, Örebro University.
    Maurice, Christian
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Ramböll Sverige AB Luleå.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geotechnical and chemical characterization of field-applied fly ash as sealing material over mine tailings2019In: International Journal of Environmental Science and Technology, ISSN 1735-1472, E-ISSN 1735-2630, Vol. 16, no 3, p. 1701-1710Article in journal (Refereed)
    Abstract [en]

    The present study addresses the geotechnical and chemical properties of sealing materials using a paper mill by-product, fly ash, on top of sulfide-bearing mine waste tailings after 5 years of field application. From a geotechnical perspective, the low in situ bulk density (≤ 1500 kg/m3) ensured a high degree of water saturation (90.2%) for the field-applied ash. The chemical characteristics and behaviors of the fly ash samples reflected a high long-term leaching capacity (liquid-to-solid ratio of 10 cm3/g) and high alkalinity (liquid-to-solid ratio of up to 500 cm3/g). The laboratory leaching results suggested that none of the elements released from the field-applied ash exceeded the EU limits for inert materials, and the concentrations of elements were far below the limits for hazardous materials at landfill sites. Based on the in situ and laboratory characterizations of the field-applied ash, the fly ash sealing material was considered geotechnically stable. However, a number of geotechnical parameters could not be measured due to the cementation of the ash. Moreover, the chemical composition of the field-applied ash exhibited considerable variations when compared with that of the raw ash generated from the same paper mill. Overall, the field-applied ash displayed high alkalinity and effectively buffered the acid generated from sulfidic tailings for long-term sealing purposes.

  • 29.
    Kasiuliene, Alfreda
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Carabante, Ivan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bhattacharya, Prosun
    Department of Sustainable Development, Environmental Science and Engineering, Royal Institute of Technology, Stockholm.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Hydrothermal carbonisation of peat-based spent sorbents loaded with metal(loid)s2019In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 26, no 23, p. 23730-23738Article in journal (Refereed)
    Abstract [en]

    Hydrothermal carbonisation (HTC) is a wet and relatively low-temperature process where, under autogenous pressures, biomass undergoes a chain of reactions leading to the defragmentation of organic matter. As well as its other uses (e.g. for producing low-cost carbon-based nano-compounds), HTC is utilised for the treatment of wet wastes, such as manure and biosludge. This study aimed to determine if hydrothermal carbonisation is a feasible treatment method for spent sorbents that are highly enriched with arsenic, chromium, copper, and zinc. The chemical properties of hydrochar and process liquid were evaluated after HTC treatment, where peat-based spent sorbents were carbonised at 230 °C for 3 h. Analysis of Fourier transform-infrared spectra revealed that during HTC, the oxygenated bonds of ethers, esters, and carboxylic groups were cleaved, and low-molecular-weight organic fragments were dissolved in the process liquid. A large fraction of arsenic (up to 62%), copper (up to 25%), and zinc (up to 36%) were transferred from the solids into the process water. Leaching of these elements from the hydrochars increased significantly in comparison with the spent sorbents.

  • 30.
    Kaasalainen, Hanna
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Sweco Environment, Luleå, Sweden.
    Lundberg, Paula
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Aiglsperger, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Alakangas, Lena
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Impact of declining oxygen conditions on metal(loid) release from partially oxidized waste rock2019In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 26, no 20, p. 20712-20730Article in journal (Refereed)
    Abstract [en]

    The best available technology for preventing the formation of acid drainage water from the sulfidic waste rock at mine closure aims to limit the oxygen access to the waste. There is, however, a concern that contaminants associated with secondary minerals become remobilized due to changing environmental conditions. Metal(loid) mobility from partially oxidized sulfidic waste rock under declining and limited oxygen conditions was studied in unsaturated column experiments. The concentrations of sulfate and metal(loid)s peaked coincidently with declining oxygen conditions from 100 to < 5 sat-% and to a lesser extent following a further decrease in the oxygen level during the experiment. However, the peak concentrations only lasted for a short time and were lower or in the similar concentration range as in the leachate from a reference column leached under atmospheric conditions. Despite the acid pH (~ 3), the overall quality of the leachate formed under limited oxygen conditions clearly improved compared with atmospheric conditions. In particular, the release of As was two orders of magnitude lower, while cationic metals such as Fe, Cu, Mn, and Zn also decreased, although to a lesser extent. Decreased sulfide oxidation is considered the primary reason for the improved water quality under limited oxygen conditions. Another reason may be the immobility of Fe with the incorporation of metal(loid)s in Fe(III) minerals, in contrast to the expected mobilization of Fe. The peaking metal(loid) concentrations are probably due to remobilization from solid Fe(III)-sulfate phases, while the relatively high concentrations of Al, Mn, and Zn under limited oxygen conditions were due to release from the adsorbed/exchangeable fraction. Despite the peaking metal(loid) concentrations during declining oxygen conditions, it is clear that the primary remediation goal is to prevent further sulfide oxidation.

  • 31.
    Warlo, Mathis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Improving trace metal characterisation of ore deposits – a crucial step towards sustainable mining2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Sustainable mining, including the utilisation of an ore body to its full potential, is becoming increasingly important for human society as the demand for metals increases. In order to maximise the recovery of useful metals, detailed characterisation of the ore prior to processing is vital. Characterisation should include major and minor ore minerals, gangue minerals, and also trace metals. Trace metals despite their low abundance are often particularly important, either due to their high economic value and criticality for society, or their negative impact on the quality of the main commodity recovered and/or the environment. To properly characterise trace metals in an ore deposit the use of micro-analytical techniques is necessary. Nowadays, a plethora of techniques exist, each with their own strengths and weaknesses. In the mining industry, automated scanning electron microscopy systems are widely used. These systems allow for rapid mineralogical characterisation and quantification of a sample and are commonly used to quantify the mineralogy of the ore feed and subsequent products. Operators of these systems benefit from prior knowledge of the mineralogy of a sample/deposit to fine-tune their processing software to deliver data of highest quality. In this study, a method to improve trace metal characterisation in ore deposits with automated scanning electron microscopy systems is presented. It is implemented as a case study on the Liikavaara Cu-(W-Au) deposit in northern Sweden. The deposit is enriched in several trace metals including Au, Ag, Bi and Sn, and is planned for production in 2023. The mine will produce Cu as the main product and Au and Ag as by-products, and the processing of the ore will be performed in the nearby Aitik plant. For this study, a detailed geological and mineralogical investigation of the deposit was performed prior to analysis with the automated scanning electron microscopy system. A good understanding of the mineralogy is necessary to be able to select a representative sample for the subsequent automated analysis and to guarantee optimal data quality produced by the automated system, and to judge the performance of the automated system, to improve the method of analysis.

    Manuscript 1 deals with the geological description and genetic aspects of the Liikavaara ore deposit. Results indicate that Liikavaara is an intrusion-related vein-style deposit. Mineralisation is hosted by quartz-tourmaline and calcite veins in a metadiabase that is partly metamorphosed to biotite schist. A 1.87 Ga granodiorite intrudes the footwall. Aplite dikes, genetically related to the intrusion, crosscut the metadiabase host rock. Mineralised veins are concentrated in and around these dikes.

    Manuscript 2 deals with method development of automated mineralogical analysis. A sample from a mineralised quartz-tourmaline vein at Liikavaara was analysed in great detail with the QEMSCAN® system. Apart from ore minerals in major and minor abundance the sample also contains ore minerals in trace quantities, e.g. Au and Ag minerals. The sample was analysed using two different analytical settings, at two different laboratories, one typical of a production-focused industrial approach and one quality-focused scientific approach. A first analysis using the industrial approach was unable to detect any Au and Ag minerals in the sample. By modification of the QEMSCAN® mineral reference library, through iterative use of the data from both the industrial- and the scientific approach, detection and quantification of Au and Ag minerals was successful. This method can be implemented as an add-on for routine industrial analysis by automated scanning electron microscopy systems to gain information on trace metal occurrence and distribution. This information can then be used for targeted sample selection for further in-depth analysis of the trace metal content and occurrence in the deposit.

  • 32.
    Kumpiene, Jurate
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Antelo, Juan
    Technological Research Institute, University of Santiago de Compostela, Spain.
    Brännvall, Evelina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Carabante, Ivan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ek, Kristina
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Komárek, Michael
    Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Czech Republic.
    Söderberg, Charlotta
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Wårell, Linda
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    In situ chemical stabilization of trace element-contaminated soil: Field demonstrations and barriers to transition from laboratory to the field : A review2019In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 100, p. 335-351Article in journal (Refereed)
    Abstract [en]

    The chemical stabilization, or immobilization, of trace elements (metals and metalloids; TE) in contaminated soil has been studied for decades. A vast number of scientific publications are available on the method performance in laboratory settings, reporting that the application of various soil amendments to contaminated soil reduces TE mobility, bioavailability and toxicity. The most commonly used soil amendments include organic matter, iron oxides, phosphates, ashes, and lately biochar, alone or in combination with each other and/or lime. Most of the implemented field studies show a certain degree of improvement in soil and/or vegetation status following amendment. Regardless the positive performance of the technique in the laboratory, field validations and demonstrations remain scarce. The establishment of a field experiment often involves permits from authorities and agreements with site owners, both of which are considerably more time-consuming than laboratory tests. Due to conservative institutional structures, public authorities have been slow to adopt alternative remediation technologies, especially when the total TE concentration in soil remains the same and all of the associated risks are not yet convincingly described. For this reason, researchers should also focus on enhancing public knowledge of alternative remediation techniques so that future projects which aim to demonstrate the effectiveness of in situ immobilization techniques under natural conditions will be supported.

  • 33.
    Oskooi, B.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Institute of Geophysics, University of Tehran, Tehran, Iran.
    Moradi, M.
    Institute of Geophysics, University of Tehran, Tehran, Iran.
    Smirnov, Maxim
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Integrated interpretation of seismic and magnetotelluric data on Shurab diapirs in Qom basin, Central Iran2019In: Acta Geophysica, ISSN 1895-6572, E-ISSN 1895-7455, Vol. 67, no 4, p. 1071-1090Article in journal (Refereed)
    Abstract [en]

    In recent decades, diapirs are frequently used for CO2 and natural gas storage due to their extremely impermeable and non-reactive characteristics. Among various approaches, we use an integrated interpretation approach to resolve the diapir no. 4 belonging to the Shurab diapirs (SD). The SD is a group of diapirs that have pierced to the surface of the Qom basin of Central Iran, which is a candidate for natural gas storages. The complex geology of the SD is the main cause that previous 2D seismic surveys across the diapir could not provide required information to propose any location for any exploration borehole. Consequentially, 28 magnetotelluric (MT) and 1 audio-magnetotelluric station were measured along a SW-NE profile. Dimensionality and strike analysis for all stations is done by the use of phase tensor analysis. We used the nonlinear conjugate gradient algorithm to invert the TE- and TM-modes data simultaneously in 2D. The resistivity model was compared with the interpreted results of the post-stack depth migration model using seismic attributes. In order to extract the determinative geological information from the low-quality seismic section, envelope, variance, sweetness and instantaneous frequencies attributes were used. The integrated interpretation of the seismic and MT data resolves a precise geometry of the salt body, location of the dense part of the diapir as well as the tectonics around the diapir. The integrated interpretation of seismic and MT data of diapir no. 4 resulted in an exploration drilling program.

  • 34.
    Conrad, Sarah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Iron isotopes in aquatic systems2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The cycling of iron (Fe) is a key component for understanding water quality and biogeochemical processes. It serves as mediator during biotic and abiotic processes, as electron acceptor during the degradation of organic matter, as surface for trace element and organic matter adsorption, and is necessary for primary production processes. Since the beginning of Fe isotope studies, researchers focussed on the ratios in soils, rivers and oceans in various environments. The aim of this study was to characterize the Fe isotope ratios from the source (e.g. soils), along the river course, through the estuaries and into the adjacent sea within the boreal landscape. Therefore, seasonal sampling of water from Swedish headwater streams (2016/2017), rivers (2016), estuaries (2013/2014) and the Baltic Sea (2013/2014) were conducted, with the purpose to better understand the role and fate of riverine Fe export. Fe is transported in two main phases from the headwater streams into the oceans: organic Fe complexes and Fe(oxy)hydroxide. It has been proposed that these Fe phases varies in response to seasonal differences in hydrology.

                          This thesis includes the first Fe isotope dataset describing seasonal variations of headwater streams on a regional scale. In the headwater streams positive and negative Fe isotopes ratios can be used to distinguish between different Fe phases. Furthermore, Fe isotope ratios in headwater streams could verify regional drought periods and the subsequent rewetting of the subsurface soils.

    Within the rivers and estuaries, we found positive Fe isotopes in the dissolved phase (< 0.22µm) and negative Fe isotopes (> 0.22µm) in the particulate phase during high discharge. The correlation between different chemical parameters, Fe and DOC showed that the Fe isotope composition during spring flood is evolving in the upper soil layers of headwater streams. Therefore, the lighter Fe isotope signal is correlated to the organic-rich soil layers of the riparian zones in forested catchments. During baseflow, particulate Fe has a positive Fe isotope signal. This shows that the Fe has different origin throughout the season within one catchment.

    Salt-induced flocculation in the estuaries and under experimental conditions, is removing about 80 % of the dissolved and particulate Fe. Newly formed colloids and particles aggregate and sediment due to small changes in salinity. This major flocculation at low salinities might cause an underestimation of riverine Fe flux. Interestingly, salinity-induced aggregation experiments revealed that Fe(oxy)hydroxide, which dominated aggregates, displayed lower Fe isotope ratios than in the river samples Fe, while organic Fe complexes in the suspension had higher Fe isotope values. The seasonal variability in Fe isotope values could not be simply linked to Fe phases but was probably also influenced by variation in source areas of Fe and processes along the flow-path that alter both Fe phases and isotopic composition.

    Within the estuarine mixing zone, no Fe isotope fractionation was observed. The Fe isotope signal is constant over time and space, which excludes fractionation processes for example by oxidation. The Fe isotope signal within the Bothnian Bay was positive showing that different surface properties of Fe-OC and Fe(oxy)hydroxide aggregates lead to the flocculation of negative Fe aggregates.

  • 35.
    Viklander, Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Österlund, Helene
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water. Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Müller, Alexandra
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Borris, Matthias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Kunskapssammanställning: Dagvattenkvalitet2019Report (Other (popular science, discussion, etc.))
    Abstract [en]

    This report summarizes stormwater pollutants, their sources, concentrations, and variations in concentrations. Practical guidance for field data collection, adoption of standard data from the literature and computer modelling are given. Furthermore, the effects on health, the environment and society, and associated regulations are discussed.

  • 36.
    Kampmann, Tobias Christoph
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Alvarenga, Rodrigo A.F.
    Ghent University, Belgium.
    Sanjuan-Delmás, David
    Ghent University, Belgium.
    Lindblom, Mats
    Boliden Mineral AB, Sweden.
    Life cycle assessment of European copper mining: A case study from Sweden2019In: Proceedings of the 15th SGA Biennial Meeting, 27-30 August 2019, Glasgow, Scotland: Life with Ore Deposits on Earth, Society for Geology Applied to Mineral Deposits , 2019, Vol. 4, p. 1577-1580Conference paper (Refereed)
    Abstract [en]

    The application of the life cycle assessment (LCA) methodology in the mining sector has the potential to evaluate the environmental sustainability of the primary production of metals. As part of a wider project on developing LCA models and methods for mining, life cycle inventory (LCI) data have been collected at two European copper-producing mine sites, Aitik (Sweden) and Cobre las Cruces (Spain). Results from Aitik, including their impact analysis, identify the use of diesel and explosives, the emission of sulfur dioxide, as well as nitrogen and other emissions in the upstream supply chain of explosives and electricity, as significant contributors to the environmental impact. These outputs have influence on the impact categories Climate Change, Photochemical Ozone Formation, Acidification, as well as Terrestrial and Marine Eutrophication. Due to the increasing incorporation of LCA into legislative demands on the mining sector, mining companies need to establish the necessary infrastructure and framework to be able to provide the required data in a fast, transparent and cost-efficient manner. For this reason, some recommendations to improve communication and data management within the companies have been established from the experience gained within this project.

  • 37.
    Bark, Glenn
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kampmann, Tobias Christoph
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Life cycle assessment of European copper mining: Aims of the SUPRIM project and difficulties in dealing with geologically complex ore deposits2019In: p. 8-9Article in journal (Other academic)
  • 38.
    Warlo, Mathis
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Wanhainen, Christina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Martinsson, Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Karlsson, Peter
    Boliden AB.
    Mineralogy and origin of the intrusion-related Liikavaara Cu-(W-Au) deposit, northern Sweden2019In: GFF, ISSN 1103-5897, E-ISSN 2000-0863Article in journal (Refereed)
    Abstract [en]

    The Liikavaara Cu-(W-Au) deposit is situated proximal to the Aitik Cu-Au deposit in northern Sweden. It shows occurrence of scheelite and enrichment in trace metals including Au, Ag and Bi. In this study, petrological, mineralogical and geochemical investigations of the host rocks and ore, and geochronological analysis of a footwall intrusion were carried out. The ore is hosted by a metadiabase partly metamorphosed to biotite schist. The wall rocks are composed of metavolcaniclastic rocks of andesitic to basaltic composition. A granodiorite intrusion occurs in the footwall and related aplite dikes cut the deposit. Veins of quartz (±tourmaline) and calcite are numerous. Mineralisation is bound to these veins and their distribution is controlled by the aplite dikes. Chalcopyrite, pyrrhotite and pyrite are major in abundance. Sphalerite, galena, scheelite, molybdenite and magnetite are minor. Gold occurs native and as electrum and Ag is mostly bound in hessite and acanthite. The bismuth mineralogy is diverse but native Bi, pilsenite, bismuthinite, and tetradymite are common. A single grain of Sb (breithauptite) was observed. The major and minor minerals show intergrowth and replacement textures. The trace minerals are found as inclusions, along the borders and in cracks in the major sulphides, sphalerite, molybdenite and quartz. The footwall intrusion is dated at 1.87 Ga and suggested to be the source for ore genesis. The dikes may have acted as pathways for the magmatic hydrothermal fluids that carried the ore from the intrusion to the host rock.

  • 39.
    Kampmann, Tobias Christoph
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    MINERS – Ett nätverk för doktorander inom gruv- och prospekteringsrelaterad forskning i Sverige2019Conference paper (Other academic)
  • 40.
    Alakangas, Lena
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Salifu, Musah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Rasmussen, Thorkild Maack
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Heino, Neea
    Geological Survey of Finland, Finland.
    Hyvönen, Eija
    Geological Survey of Finland, Finland.
    Karlsson, Teemu
    Geological Survey of Finland, Finland.
    Panttila, Hannu
    Geological Survey of Finland, Finland.
    Pietilä, Raija
    Geological Survey of Finland, Finland.
    Tornivaara, Anna
    Geological Survey of Finland, Finland.
    Turunen, Kaisa
    Geological Survey of Finland, Finland.
    Lu, Jinmei
    UiT The Arctic University of Norway, Norway.
    Fu, Shuai
    UiT The Arctic University of Norway, Norway.
    Bui, Minh Tuan
    UiT The Arctic University of Norway, Norway.
    Heiderscheidt, Elisangela
    University of Oulu, Finland.
    Postila, Heini
    University of Oulu, Finland.
    Leiviskä, Tiina
    University of Oulu, Finland.
    Ronkanen, Anna-kaisa
    University of Oulu, Finland.
    Kujala, Katharina
    University of Oulu, Finland.
    Khan, Uzair
    University of Oulu, Finland.
    Gogoi, Harshita
    University of Oulu, Finland.
    Min-North: Development, Evaluation and Optimization of Measures to Reduce the  Environmental Impact of Mining Activities in Northern Regions2019Report (Other academic)
    Abstract [en]

    The Min-North (Development, Evaluation and Optimization of Measures to Reduce the Environment Impact of Mining Activities in Northern Regions) project was a trans-national cooperative project, with participants from the Geological Survey of Finland (GTK), University of Oulu (UO), UiT The Arctic University of Norway (UiT), Luleå University of Technology (LTU) and SMEs from Sweden, Finland and Norway. The project was funded by Interreg Nord and Norrbottens länsstyrelse. The participants have expertise in mine waste management, mine water treatment and geophysics. The overall aim of the project was to enhance the development of environmental protection technologies. An associated goal was to deepen cross-border cooperation by creating a larger critical mass of researchers in mine waste management and local SMEs in the Northern regions with greater capacities to disseminate and implement new methods, products and services. The project ran for 36 months from the 1st of January 2016 to the end of December 2018.

     

  • 41.
    Otsuki, Akira
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Ecole Nationale Supérieure de Géologie, GeoRessources UMR 7359 CNRS, University of Lorraine, Vandoeuvre-lès-Nancy, France.
    Gonçalves, Pedro Pereira
    Ecole Nationale Supérieure de Géologie, GeoRessources UMR 7359 CNRS, University of Lorraine, Vandoeuvre-lès-Nancy, France.
    Stieghorst, Christian
    Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München,Garching, Germany.
    Révay, Zsolt
    Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Garching, Germany.
    Non-Destructive Characterization of Mechanically Processed Waste Printed Circuit Boards: X-ray Fluorescence Spectroscopy and Prompt Gamma Activation Analysis2019In: Journal of Composites Science, E-ISSN 2504-477X, Vol. 3, no 2, article id 54Article in journal (Refereed)
    Abstract [en]

    This work aimed to characterize the deportment/concentration and liberation/association of the metals and light elements within mechanically processed waste printed circuit boards (PCBs) that hold the complex and heterogeneous structure and distribution of different material components. Waste PCBs passed through a series of mechanical processing (i.e., comminution and sieving) for metal recovery and were then characterized without further destroying the particles in order to capture their heterogeneity. The characterizations were performed in a laboratory and large-scale neutron facility. The results obtained with a portable X-ray fluorescence spectroscopy and prompt gamma activation analysis were compared and confirmed the good agreement and complementarities in general. The advantages and disadvantages of the two different methods were identified and discussed in this paper, in relation to their application to the analysis of mechanically processed PCB particles.

  • 42.
    Kampmann, Tobias Christoph
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ny mineralutställning på gång2019In: Geologiskt Forum, ISSN 1104-4721, Vol. 101, p. 9-9Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    På Luleå tekniska universitet håller vi just nu på med att skapa en modern mineralutställning som visar den geologiska forskningen vid universitetet, men som också ska väcka intresse för prospektering och industriprocesser kopplade till mineral och metallurgi.

  • 43.
    Murray, Jesica
    et al.
    Instituto de Bio y Geo Ciencias del Noroeste Argentino, Universidad Nacional de Salta - CONICET, 4405 Rosario de Lerma, Argentina. Laboratoire d'Hydrologie et de Géochimie de Strasbourg, Université de Strasbourg, EOST, CNRS, Strasbourg, France.
    Nordstrom, Darrell Kirk
    United States Geological Survey, Boulder, CO, United States of America.
    Dold, Bernhard
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Orué, Maria Romero
    Instituto de Bio y Geo Ciencias del Noroeste Argentino, Universidad Nacional de Salta - CONICET, Rosario de Lerma, Argentina.
    Kirschbaum, Alicia
    Instituto de Bio y Geo Ciencias del Noroeste Argentino, Universidad Nacional de Salta - CONICET, Rosario de Lerma, Argentina.
    Origin and geochemistry of arsenic in surface and groundwaters of Los Pozuelos basin, Puna region, Central Andes, Argentina2019In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 697, article id 134085Article in journal (Refereed)
    Abstract [en]

    Los Pozuelos is a closed basin in the Puna region of NW Argentina, Central Andes. This is a semi-arid region where closed basins are the most important feature for the hydrologic systems. The center of the basin is occupied by a fluctuating playa lake called Los Pozuelos lagoon, which constitutes a UNESCO Biosphere Reserve. This is one of the most populated closed basins in the Argentinian Puna and residents use groundwater for drinking and cooking. Lowest concentrations of As and dissolved solids are in the headwaters of the rivers (1.46–27 μg/L) and the highest concentrations are in the lagoon (43.7–200.3 μg/L). In groundwater, arsenic concentrations increase from the outer ring aquifer (3.82–29.7 μg/L) composed of alluvial-alluvial fan sediments to the inner lacustrine aquifer (10–113 μg/L) that surround the playa lake. Moreover, high concentrations of As during the dry season (90.2 and 113 μg/L), Na/K mass ratios (0.2 and 0.3), and formation of Na-rich efflorescent salts suggest that high evaporation rates increases As concentration, while rainwater dilutes the concentration during the wet season. As(V) is the dominant species in all the water types, except for the lagoon, where As(III) occasionally dominates because of organic matter buildup. There are at least three potential sources for As in water i) oxidation of As sulfides in Pan de Azúcar mine wastes, and acid mine drainage discharging into the basin; ii) weathering and erosion of mineralized shales; iii) weathering of volcanic eruptive non-mineralized rocks. Because it is a closed basin, the arsenic released from the natural and anthropogenic sources is transported in solution and in fluvial sediments and finally accumulates in the center of the basin where the concentration in water increases by evaporation with occasional enhancement by organic matter interaction in the lagoon.

  • 44.
    Darwesh, Ali
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Parameters optimization of oil well drilling operations2019Doctoral thesis, comprehensive summary (Other academic)
  • 45.
    Kasiuliene, Alfreda
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Peat Coated with Iron Oxides: Purification of Metal(loid)-Contaminated Water and Treatment of the Spent Adsorbent2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In Sweden due to the industrial activities, such as wood impregnation, multiple point sources of arsenic (As) contamination in soil and water bodies are scattered over the country. Metals, such as chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), cadmium (Cd) or zinc (Zn) at varying concentrations are usually present as well. Since adsorption is a common method to purify contaminated water, research and development of adsorbents have been actively carried out in the last few decades. However, seldom spent sorbent is safely handled afterwards and often end up in landfill, thus creating new problems and posing new risks to humans and environment.

    The aim of this study was to develop a waste-based adsorbent for simultaneous removal of As and associated metals: Cr, Cu and Zn, and to analyse sustainable ways how to manage the spent adsorbent without creating secondary pollution.

    In the model system two well-establish adsorbents: Fe oxides (deriving from FeCl3) and peat (waste-based), were combined and the concept of simultaneous removal of cationic and anionic contaminants was tested in a batch adsorption experiment. Due to Fe coating, removal of As and Cr increased by 80% and 30%, respectively, as compared to non-coated peat. Removal of Cu and Zn was higher (up to 15%) on non-coated peat than on Fe-coated peat. Similar results were obtained in the up-scaled column adsorption experiment, where Fe salt was substituted with a waste-based Fe hydrosol. Within the same pH environment (pH=5), Fe-coated peat effectively adsorbed all four investigated contaminants (As, Cr, Cu and Zn). Non-coated peat was effective for Cr, Cu and Zn. While, Fe oxides (coated on sand) adsorbed only As.

    Three management strategies for spent adsorbents, obtained after column adsorption experiment, were investigated in this study. i) Long-term deposit in a landfill was simulated by exposing spent adsorbents to a reducing environment and evaluating metal(loid) leaching. Leaching of As increased manifold (up to 60% in a 200-day experiment) as compared to the standardized batch leaching experiment under oxidizing conditions. It was determined that about one third of As(V) was reduced to As(III), which is more mobile and toxic. ii) Valorisation of the spent adsorbent was attempted through hydrothermal carbonisation. It was expected that obtained hydrochar could be used as a beneficial soil amendment. However, treatment resulted in the process liquid and the hydrochar both having high loads of As, Cu and Zn. Additional treatment of process water and hydrochar imply higher management costs for spent adsorbents. iii) Possibility of thermal destruction was investigated by combusting spent adsorbents. After the treatment volume of the waste (ash) was by 80-85% smaller as compared to spent adsorbents. Combustion at higher temperature (1100 °C vs 850 °C) resulted into a weaker metal(loid) leaching from ashes. Furthermore, co-combustion with calcium (Ca)-rich lime (waste-based) decreased leaching of all four investigated elements, Cr in particular, below the limit values for waste being accepted at landfills for hazardous waste. Therefore, combustion enabled possibility of safe and long-term deposit of As-bearing ashes. At the same time, less As would be circulating in society. 

    For the future work, studies that could broaden the spectrum of contaminants targeted by Fe-coated peat would be beneficial. At the same time it is important not only to find alternative utilisation methods for Fe-coated peat, but also investigate other management options for the spent adsorbents.

  • 46.
    Saintilan, Nicolas J.
    et al.
    Department of Earth Sciences, University of Geneva, Geneva, Switzerland.
    Spangenberg, Jorge E.
    Institute of Earth Surface Dynamics, University of Lausanne, Lausanne, Switzerland.
    Chiaradia, Massimo
    Department of Earth Sciences, University of Geneva , Geneva, Switzerland.
    Chelle-Michou, Cyril
    Department of Earth Sciences, University of Geneva, Geneva, Switzerland.
    Stephens, Michael B.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Formerly Geological Survey of Sweden (SGU), Uppsala, Sweden.
    Fontboté, Lluís
    Department of Earth Sciences, University of Geneva, Geneva, Switzerland.
    Petroleum as source and carrier of metals in epigenetic sediment-hosted mineralization2019In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 8283Article in journal (Refereed)
    Abstract [en]

    Sediment-hosted ore deposits contribute a significant amount (up to 65%) of the global resources of lead and zinc. Among them, the Mississippi-Valley type deposits and related oil fields often comprise large-scale hydrothermal systems where regional host rocks are stained with disseminated liquid petroleum (crude oil) and other organic compounds. Current models for the formation of those epigenetic Pb-Zn sulphide deposits consider that metals are mostly leached from basement rocks and their detrital erosional products, and transported by oxidized basinal hydrothermal fluids as chloride complexes. Sulphide precipitation mainly occurs when these basinal brines interact with fluids rich in reduced sulphur species produced mostly by thermochemical sulphate reduction (TSR) mediated by hydrocarbons. Here, using organic geochemistry and Pb isotopes, we provide evidence that petroleum and associated water were key for the formation of sulphide mineralization in the world-class sandstone-hosted ore deposit at Laisvall, not only by supplying reduced sulphur but also by contributing metals in significant amounts. The lead originally found in bitumen of the Alum Shale Formation was transported —during an arc-continent collisional event— by liquid petroleum and associated water to the site of sulphide mineralization. The alteration of petroleum by TSR made lead available for precipitation as sulphide. The petroleum-associated lead represents 40 to 60% of the metal budget in the deposit, the remainder being sourced by leaching of basement rocks.

  • 47.
    Nyström, Elsa
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kaasalainen, Hanna
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Alakangas, Lena
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Prevention of sulfide oxidation in waste rock by the addition of lime kiln dust2019In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 26, no 25, p. 25945-25957Article in journal (Refereed)
    Abstract [en]

    During the operation of a mine, waste rock is often deposited in heaps and usually left under ambient conditions allowing sulfides to oxidize. To focus on waste rock management for preventing acid rock drainage (ARD) formation rather than ARD treatment could avoid its generation and reduce lime consumption, costs, and sludge treatment. Leachates from 10 L laboratory test cells containing sulfide-rich (> 60% pyrite) waste rock with and without the addition of lime kiln dust (LKD) (5 wt.%) were compared to each other to evaluate the LKD’s ability to maintain near neutral pH and reduce the sulfide oxidation. Leaching of solely waste rock generated an acidic leachate (pH < 1.3) with high concentrations of As (21 mg/L), Cu (20 mg/L), Fe (18 g/L), Mn (45 mg/L), Pb (856 μg/L), Sb (967 μg/L), S (17 g/L), and Zn (23 mg/L). Conversely, the addition of 5 wt.% LKD generated and maintained a near neutral pH along with decreasing of metal and metalloid concentrations by more than 99.9%. Decreased concentrations were most pronounced for As, Cu, Pb, and Zn while S was relatively high (100 mg/L) but decreasing throughout the time of leaching. The results from sequential extraction combined with element release, geochemical calculations, and Raman analysis suggest that S concentrations decreased due to decreasing sulfide oxidation rate, which led to gypsum dissolution. The result from this study shows that a limited amount of LKD, corresponding to 4% of the net neutralizing potential of the waste rock, can prevent the acceleration of sulfide oxidation and subsequent release of sulfate, metals, and metalloids but the quantity and long-term stability of secondary minerals formed needs to be evaluated and understood before this method can be applied at a larger scale.

  • 48.
    Kampmann, Tobias Christoph
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Proceedings of the Visual3D conference 2019, 1–2 October 2019, Uppsala, Sweden: Visualization of 3D/4D models in geosciences, exploration and mining2019Conference proceedings (editor) (Refereed)
    Abstract [en]

    Dear colleagues,

    On behalf of the organizing committee of the Visual3D conference 2019, with the theme “Visualization of 3D/4D models in geosciences, exploration and mining”, I would like to present this proceedings document, containing all abstract contributions for which publication permission has been granted by the authors.

    EIT Raw Materials is especially acknowledged as the main sponsor of this event through the Visual3D network of infrastructure.

    We wish to thank all the contributors who through their efforts made this conference possible, and hope to see you all at a similar event in the near future.

    Yours sincerely,

    Tobias C. Kampmann, PhDConference coordinator, Visual3D conference 2019

  • 49.
    Firsching, Markus
    et al.
    Fraunhofer Development Centre X-ray Technology EZRT, Fürth, Germany.
    Bauer, Christine
    Fraunhofer Development Centre X-ray Technology EZRT, Fürth, Germany.
    Wagner, Rebecca
    Fraunhofer Development Centre X-ray Technology EZRT, Fürth, Germany.
    Ennen, Alexander
    Fraunhofer Development Centre X-ray Technology EZRT, Fürth, Germany.
    Ahsan, Amit
    SECOPTA analytics, Germany.
    Kampmann, Tobias Christoph
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Tiu, Glacialle
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Valencia, Alvaro
    University of Chile.
    Casali, Aldo
    University of Chile.
    Montes Atenas, Gonzalo
    University of Chile.
    REWO-SORT Sensor Fusion for Enhanced Ore Sorting: a Project Overview2019Conference paper (Refereed)
    Abstract [en]

    Among the numerous challenges recently confronting the mining industry is the need to process ore with successively lower grades due to the continuous depletion of high-grade deposits. This increases the consumption of energy and water and, thus, the operational costs at a mine site. Multimodal sorting represents a promising technique to achieve pre-concentration of valuable minerals already at an early stage in the metallurgical process.In the ERA-MIN2 project “Reduction of Energy and Water Consumption of Mining Operations by Fusion of Sorting Technologies LIBS and ME-XRT” (REWO-SORT), a fusion technology including laser-induced breakdown spectroscopy (LIBS) and multi energy X-ray transmission (ME-XRT) is being developed by a multidisciplinary expert consortium. The project aims at classifying crushed mineral particles on a conveyor belt with the aid of deep learning technologies. In addition, the operating conditions to work with high throughput while keeping a particle monolayer on the conveyor belt have been identified. The latter objective is addressed using discrete element method (DEM) simulations. Parameter calibrations were experimentally obtained using a copper sulfide ore from the Rafaela mining company (Chile). The combination of LIBS and ME-XRT is promising, as they complement each other regarding analytical and particle selection capabilities: LIBS can provide an elemental analysis of the sample surface, while ME-XRT produces volumetric data with lower accuracy. Both sensors will be combined to extrapolate accurate and representative volumetric data, thereby securing an optimal particle selection at high throughputs. First measurements and analyses of ore samples using LIBS and ME-XRT, as well as their correlation with the Cu concentration obtained by reference lab analysis will be presented and discussed. Preliminary DEM studies indicate the existence of a threshold of conveyor belt surface area covered with particles of around 85%. Above this value the particle monolayer cannot be maintained, imposing another restriction for the speed of sensor analysis.

  • 50.
    Otsuki, Akira
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Ecole Nationale Supérieure de Géologie, GeoRessources UMR 7359 CNRS, University of Lorraine, Vandoeuvre-lès-Nancy, France.
    Gonçalves, Pedro Pereira
    Ecole Nationale Supérieure de Géologie, GeoRessources UMR 7359 CNRS, University of Lorraine, Vandoeuvre-lès-Nancy, France.
    Leroy, Emilien
    Ecole Nationale Supérieure de Géologie, GeoRessources UMR 7359 CNRS, University of Lorraine, Vandoeuvre-lès-Nancy, France.
    Selective Milling and Elemental Assay of Printed Circuit Board Particles for Their Recycling Purpose2019In: Metals, ISSN 2075-4701, Vol. 9, no 8, article id 899Article in journal (Refereed)
    Abstract [en]

    Selective/preferential milling of printed circuit board (PCB) particles followed by non-destructive characterization of the mill products was performed in order to understand the effects of different feed masses into a hammer mill and different milling time on the metal recovery and enrichment ratio. Those are important variables affecting and determining the process performance and capacity. The milling tests and elemental assay characterization were conducted by using a hammer mill and a portable X-ray fluorescence analysis (XRF), respectively. The results showed the preferential metal concentration/enrichment was achieved for several elements and their degree was varied depending on the parameters. Using the experimental data, predictive models of metal recovery were developed and the global trend of metal recoveries was observed under different mill feed and milling time and discussed.

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