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- Allard, Bert, 1945-, et al.
(författare)
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Black shale : a biogeochemical archive
- 2014
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Ingår i: Sedimentary Pore Space Cementation: Role of Microbes. ; , s. 6-
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Konferensbidrag (refereegranskat)
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- Allard, Bert, 1945-, et al.
(författare)
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Metal Exchangeability in the REE-Enriched Biogenic Mn Oxide Birnessite from Ytterby, Sweden
- 2023
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Ingår i: Minerals. - : MDPI. - 2075-163X. ; 13:8
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Tidskriftsartikel (refereegranskat)abstract
- A black substance exuding from fractures was observed in 2012 in Ytterby mine, Sweden, and identified in 2017 as birnessite with the composition Mx[Mn(III,IV)](2)O-4 center dot(H2O)n. M is usually calcium and sodium, with x around 0.5. The Ytterby birnessite is unique, with M being calcium, magnesium, and also rare earth elements (REEs) constituting up to 2% of the total metal content. The biogenic origin of the birnessite was established in 2018. Analysis of the microbial processes leading to the birnessite formation and the REE enrichment has continued since then. The process is fast and dynamic, as indicated by the depletion of manganese and of REE and other metals in the fracture water during the passage over the precipitation zone in the mine tunnel. Studies of the exchangeability of metals in the structure are the main objective of the present program. Exposure to solutions of sodium, calcium, lanthanum, and iron led to exchanges and altered distribution of the metals in the birnessite, however, generating phases with almost identical structures after the exchanges, and no new mineral phases were detected. Exchangeability was more efficient for trivalent elements (REE) over divalent (calcium) and monovalent (sodium) elements of a similar size (ionic radii 90-100 pm).
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| 9. |
- Allard, Bert, 1945-, et al.
(författare)
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Mining waste management in the Baltic Sea Region : Min-Novation project
- 2013
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Bok (refereegranskat)abstract
- Mining waste and what to do about it is a common challenge facing companies, local authorities, environmental organizations, policymakers and increasingly other stakeholders in several countries of the Baltic Sea Region. From 2011 to 2013, a network of scientific and regional expertise brought together in the Min-Novation project has put this topic in the spotlight. The importance of the management of waste from extractive industries is due to the substantial share this waste has in the overall stream of waste generated in the EU. In 2010, 672 Mt or 28.3% of the total waste generated in the EU was attributable to the mining and quarrying industry, second only to construction (34.4%) and ahead of manufacturing (11.0%) and households (8.7%)1. Apart from this, mining waste is the raw material for one of the more visible man-made landmarks that surround us, with waste heaps of various shapes and sizes dotting the landscape up and down the Baltic Sea Region. Despite this dual prominence, mining waste is most often seen only as an environmental problem and in no way a resource. To move away from a one-sided view of mining waste, a life-cycle approach, which recognises that value can be recovered from waste and re-introduced into the product cycle is of the essence. It cannot be stressed enough that mining waste is a source of secondary raw materials, the use of which helps to protect the natural mineral deposits for future generations. Equally important is an appreciation of how the waste can be re-cycled in the excavation process (preventionand recovery) and adapted to create value for local communities (reclamation and revitalisation). However, for there to be effective mining waste management, both in the prevention stage, as well as in the recovery stage, and finally during land reclamation many conditions must be fulfilled. Of these the most important are access to appropriate technologies and methods and common sense legislation. Another condition not without importance is social acceptance for the recovery of waste located in old landfills. The Min-Novation Network over a span of 3 years has worked to understand and appreciate mining waste both as a corporate, community, regulatory and strategic issue. Set against the background of mining activity and waste management in the partner countries: Estonia, Finland, Germany, Norway, Poland and Sweden, both good practices and problem areas, which need to be addressed have been presented in this monograph. The purpose of this monograph is to show a cross-section of topics that affect how mining waste management works today, and which will play a decisive role in whether management of mining waste remains – an issue of primarily local relevance or whether it becomes a growth opportunity of national and EU-wide importance. The monograph focuses primarily on issues related to the management of waste from extractive industries in the countries whose representatives were involved in the Min-Novation project. Examples from outside the Baltic Sea Region of the use of waste heaps as an industrial heritage of the mining regions and also as attractions for local communities are presented as well. Indeed, every experience is valuable for the environment and socio-economic development of the Baltic Sea Region.
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- Allard, Bert, 1945-, et al.
(författare)
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Neutralisation of an acidic pit lake by alkaline waste products
- 2014
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Ingår i: Environmental Science and Pollution Research. - : Springer. - 0944-1344 .- 1614-7499. ; 21:11, s. 6930-6938
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Tidskriftsartikel (refereegranskat)abstract
- A former open pit where black shale (alum shale) was excavated during 1942-1965 has been water filled since 1966. The water chemistry was dominated by calcium and sulphate and had a pH of 3.2-3.4 until 1997-1998, when pH was gradually increasing. This was due to the intrusion of leachates from alkaline cement waste deposited close to the lake. A stable pH of around 7.5 was obtained after 6-7 years. The chemistry of the pit lake has changed due to the neutralisation. Concentrations of some dissolved metals, notably zinc and nickel, have gone down, as a result of adsorption/co-precipitation on solid phases (most likely iron and aluminium hydroxides), while other metals, notably uranium and molybdenum, are present at elevated levels. Uranium concentration is reaching a minimum of around pH 6.5 and is increasing at higher pH, which may indicate a formation of neutral and anionic uranyl carbonate species at high pH (and total carbonate levels around 1 mM). Weathering of the water-exposed shale is still in progress.
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