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Faimon J, Baldík V, Buriánek D, Rez J, Štelcl J, Všianský D, Sedláček J, Dostalík M, Nečas J, Novotný R, Hadacz R, Kryštofová E, Novotná J, Müller P, Krumlová H, Čáp P, Faktorová K, Malík J, Roháč J, Kycl P, Janderková J. Historical ferrous slag induces modern environmental problems in the Moravian Karst (Czech Republic). THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 847:157433. [PMID: 35868374 DOI: 10.1016/j.scitotenv.2022.157433] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/26/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Ferrous slag produced by a historic smelter is washed from a slagheap and transported by a creek through a cave system. Slag filling cave spaces, abrasion of cave walls / calcite speleothems, and contamination of the aquatic environment with heavy metals and other toxic components are concerns. We characterize the slag in its deposition site, map its transport through the cave system, characterize the effect of slag transport, and evaluate the risks to both cave and aqueous environments. The study was based on chemical and phase analysis supported laboratory experiments and geochemical modeling. The slag in the slagheap was dominated by amorphous glass phase (66 to 99 wt%) with mean composition of 49.8 ± 2.8 wt% SiO2, 29.9 ± 1.6 wt% CaO, 13.4 ± 1.2 wt% Al2O3, 2.7 ± 0.3 wt% K2O, and 1.2 ± 0.1 wt% MgO. Minerals such as melilite, plagioclase, anorthite, and wollastonite / pseudowollastonite with lower amounts of quartz, cristobalite, and calcite were detected. Slag enriches the cave environment with Se, As, W, Y, U, Be, Cs, Sc, Cd, Hf, Ba, Th, Cr, Zr, Zn, and V. However, only Zr, V, Co, and As exceed the specified limits for soils (US EPA and EU limits). The dissolution lifetime of a 1 mm3 volume of slag was estimated to be 27,000 years, whereas the mean residence time of the slag in the cave is much shorter, defined by a flood frequency of ca. 47 years. Consequently, the extent of slag weathering and contamination of cave environment by slag weathering products is small under given conditions. However, slag enriched in U and Th can increase radon production as a result of alpha decay. The slag has an abrasive effect on surrounding rocks and disintegrated slag can contaminate calcite speleothems.
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Affiliation(s)
- Jiří Faimon
- Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech Republic; Czech Geological Survey, Leitnerova 22, 658 69 Brno, Czech Republic.
| | - Vít Baldík
- Czech Geological Survey, Leitnerova 22, 658 69 Brno, Czech Republic
| | - David Buriánek
- Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech Republic; Czech Geological Survey, Leitnerova 22, 658 69 Brno, Czech Republic
| | - Jiří Rez
- Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech Republic; Czech Geological Survey, Leitnerova 22, 658 69 Brno, Czech Republic
| | - Jindřich Štelcl
- Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech Republic; Department of Biology, Faculty of Education, Masaryk University, Poříčí 623/7, 603 00 Brno, Czech Republic
| | - Dalibor Všianský
- Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech Republic
| | - Jan Sedláček
- Czech Geological Survey, Leitnerova 22, 658 69 Brno, Czech Republic
| | - Martin Dostalík
- Czech Geological Survey, Klárov 131/3, 118 21 Praha, Czech Republic
| | - Jiří Nečas
- Czech Geological Survey, Leitnerova 22, 658 69 Brno, Czech Republic
| | - Roman Novotný
- Czech Geological Survey, Leitnerova 22, 658 69 Brno, Czech Republic
| | - Roman Hadacz
- Czech Geological Survey, Leitnerova 22, 658 69 Brno, Czech Republic
| | - Eva Kryštofová
- Czech Geological Survey, Leitnerova 22, 658 69 Brno, Czech Republic
| | - Jitka Novotná
- Czech Geological Survey, Leitnerova 22, 658 69 Brno, Czech Republic
| | - Pavel Müller
- Czech Geological Survey, Leitnerova 22, 658 69 Brno, Czech Republic
| | - Hana Krumlová
- Institute of Physics of the Earth, Masaryk University, Tvrdého 12, 602 00 Brno, Czech Republic
| | - Pavel Čáp
- Czech Geological Survey, Klárov 131/3, 118 21 Praha, Czech Republic
| | | | - Jan Malík
- Czech Geological Survey, Klárov 131/3, 118 21 Praha, Czech Republic
| | - Jakub Roháč
- Czech Geological Survey, Klárov 131/3, 118 21 Praha, Czech Republic
| | - Petr Kycl
- Czech Geological Survey, Klárov 131/3, 118 21 Praha, Czech Republic
| | - Jana Janderková
- Czech Geological Survey, Leitnerova 22, 658 69 Brno, Czech Republic
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van der Ent A, Parbhakar-Fox A, Erskine PD. Treasure from trash: Mining critical metals from waste and unconventional sources. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 758:143673. [PMID: 33261870 DOI: 10.1016/j.scitotenv.2020.143673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 11/07/2020] [Accepted: 11/08/2020] [Indexed: 06/12/2023]
Abstract
To meet future technological demands of our growing global community new sources of industry critical metals need to be identified. To meet these demands, extracting minerals from larger, lower grade deposits across most commodities is required, which in turn generates ever increasing amounts of mine wastes. We propose that agromining could be used to enables access to unconventional resources not viable using existing minerals processing techniques. This innovative technique relies on so-called hyperaccumulator plants to bio-concentrate high levels of metals into living biomass which can then be extracted from the harvested bio-ore. Producing critical metals, such as nickel, cobalt and thallium, efficiently and sustainably using agromining appears to be well within reach, but this technology needs industrial champions to develop demonstration sites that are scaled appropiately in areas where it is feasible.
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Affiliation(s)
- Antony van der Ent
- Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, Queensland, Australia.
| | - Anita Parbhakar-Fox
- W.H. Bryan Mining & Geology Research Centre, Sustainable Minerals Institute, The University of Queensland, Queensland, Australia
| | - Peter D Erskine
- Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, Queensland, Australia
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Grinding Kinetics of Slag and Effect of Final Particle Size on the Compressive Strength of Alkali Activated Materials. MINERALS 2019. [DOI: 10.3390/min9110714] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This study aims to model grinding of a Polish ferronickel slag and evaluate the particle size distributions (PSDs) of the products obtained after different grinding times. Then, selected products were alkali activated in order to investigate the effect of particle size on the compressive strength of the produced alkali activated materials (AAMs). Other parameters affecting alkali activation, i.e., temperature, curing, and ageing time were also examined. Among the different mathematical models used to simulate the particle size distribution, Rosin–Rammler (RR) was found to be the most suitable. When piecewise regression analysis was applied to experimental data it was found that the particle size distribution of the slag products exhibits multifractal character. In addition, grinding of slag exhibits non-first-order behavior and the reduction rate of each size is time dependent. The grinding rate and consequently the grinding efficiency increases when the particle size increases, but drops sharply near zero after prolonged grinding periods. Regarding alkali activation, it is deduced that among the parameters studied, particle size (and the respective specific surface area) of the raw slag product and curing temperature have the most noticeable impact on the compressive strength of the produced AAMs.
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