ERE4.5 | Mining and Post-mining innovative solutions for mining waste, and risk assessment for sustainable development
EDI
Mining and Post-mining innovative solutions for mining waste, and risk assessment for sustainable development
Co-organized by NH10
Convener: Feven DestaECSECS | Co-conveners: AL HEIB Marwan, Emmanouil Varouchakis, Adriana Guatame-GarciaECSECS, Sara KasmaeeECSECS, Hernan Flores, Nasser Madani
Orals
| Thu, 18 Apr, 16:15–18:00 (CEST)
 
Room -2.16
Posters on site
| Attendance Thu, 18 Apr, 10:45–12:30 (CEST) | Display Thu, 18 Apr, 08:30–12:30
 
Hall X4
Orals |
Thu, 16:15
Thu, 10:45
The closed mines present several challenges for scientific and mines regions. Post-mining activities in the field of geosciences often involve addressing various geology, geotechnical environmental concerns and challenges in the research and application fields. Here are some key aspects related to post-mining and geosciences in the context of environmental considerations:
1. Hazards Evaluation: Ground Movement
o Subsidence can occur during and after mining operations, and the overlying strata collapse or settle into these voids, causing surface depressions. Geoscientists play a crucial role in assessing the potential for subsidence and its impact on the environment and infrastructure.
2. Hazards Mitigation Methods
o Reclamation Geoscientists work on reclamation plans to restore mined areas to their natural state or to suitable post-mining land uses.
o Geotechnical Engineering: Geoscientists and geotechnical engineers collaborate to develop stability assessments and engineering solutions to prevent or minimize ground movement hazards. Techniques such as backfilling, soil stabilization, and structural supports can be employed.
3. Energy and Post-Mine Challenges
o Mine Water Management: Geoscientists help design and implement water management strategies, including the treatment of acid mine drainage (AMD) and the utilization of mine water for geothermal heating or cooling.
o Renewable Energy development: Converting former mining sites into renewable energy facilities, such as solar or wind farms, is a sustainable post-mining option.
4. Storage energy and CO2 and Post-Mine
o Carbon Capture and Storage (CCS): Evaluating the geological and hydrogeological characteristics of potential storage sites is crucial for ensuring the safe and permanent sequestration of CO2.
o Post-Mine Site Selection: Post-mining sites that are no longer suitable for mining operations may be repurposed for CCS or other forms of carbon sequestration.
5. Development of open-pit lake: Geoscientists and hydrogeologists work define the long-term stability of the slope stability, define the reshaping of the land, replanting vegetation, and ensuring proper drainage to mitigate hazards like erosion and water quality degradation.
6. Revalorization of mining tailing storage facilities: The dumps can be both an environmental hazard and an asset for further reprocessing of tailings materials to further extract metals and elements.
7. Sustainable mine waste management strategies
8. Innovative tools and enhanced methodologies for mine waste sampling, characterization, and environmental assessment
9. Transformation of mine waste into energy
10. Reactivation and transition of post-mining repositories and new societal and economical perspectives

Orals: Thu, 18 Apr | Room -2.16

Chairpersons: Feven Desta, AL HEIB Marwan
16:15–16:20
16:20–16:30
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EGU24-8964
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On-site presentation
Ayse Kaslilar, Zbigniew Wilczynski, Christopher Juhlin, and Mehrdad Bastani

The increasing need for mineral resources and critical rare earth elements (REE) due to the transition to clean energy has attracted interest in mine wastes as they may contain significant amounts of REE that were not of interest in the past but are today. Detailed knowledge about the 3D geometry and size of the waste deposits and their mineral content is important to understanding whether waste tailings can serve as a secondary resource, contributing to the energy transition, sustainability, and the circular economy, and promoting recycling.  Geophysical methods can provide information on the geometry, and help to characterize and estimate the size of the mine waste. In the last two decades developments in sensor and computational technology have enabled cost-effective and environmentally friendly seismic ambient noise methods to be widely applied for imaging the subsurface. Among others, one of the ambient noise methods is the horizontal-to-vertical spectral ratio (HVSR) method, which is an efficient technique widely used for site characterization, estimating the thickness of overburden above bedrock, monitoring landslide, and examining the stability of tailing dams.

In this study, ambient noise data and the HVSR method are used to estimate the thickness and delineate the 3D geometry of mine tailings. We use three-component (3C) ambient noise data that we collected with 50m spacing between the sensors and profiles in one of the non-active mine tailings of Nordic Iron Ore in Blötberget, Sweden, which might be a potential resource for REE.  We process the 3C data and obtain the fundamental frequency at each receiver location. Moreover, one-component ambient noise data that we collected along two perpendicular profiles with a receiver spacing of 5m are used to estimate the surface wave velocity. Combining the fundamental frequency and velocity information, we calculate the depth of the contrasting interface. We show our preliminary results obtained from ambient noise data and compare them with the previous results from the radio magnetotelluric measurements conducted by Geological Survey of Sweden.

This work is part of a project supported by the Geological Survey of Sweden. We gratefully acknowledge this support.

How to cite: Kaslilar, A., Wilczynski, Z., Juhlin, C., and Bastani, M.: Delineation of mine tailings by ambient noise horizontal-to-vertical spectral ratio method, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8964, https://doi.org/10.5194/egusphere-egu24-8964, 2024.

16:30–16:40
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EGU24-14563
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On-site presentation
Anita Parbhakar-Fox, Laura Jackson, Kamini Bhowany, Rosie Blannin, Allan Gomes, and LeXi K'ng

Meeting the needs of the energy transition is a once-in-a-generation challenge like no other before. To meet the projected metal demand to support things, the global community will produce increased volumes of mine waste requiring best practice management. Mine waste is suspected to be a host of critical metals and minerals (i.e., cobalt, indium, REEs, Ga and Ge have typically been by-products since concentrating in waste streams). If identified as significant resources of critical metals, remining waste can support Australia’s effort to adopt circular economy principles, a notable socio-economic driver.

Whilst this sounds relatively straightforward, practical investigations show this is anything but. From sampling to metal recovery, mine waste materials are complex and heterogenous originating, in some cases, from multiple ore sources, processed by different methods, and eventually subjected to weathering under changing climatic conditions. Therefore, multi-scale multidisciplinary characterisation is required to truly develop a valorisation process which not only recovers critical metals and minerals, but also substantially reduces any associated environmental legacy issues and mining footprints.    

In collaboration with the QLD, NT, NSW and SA State Governments and Geoscience Australia mine waste (i.e., tailings, slag, waste rock and metallurgical residues) at historical and operational mines across the country have been sampled (n= 50 of 77: 2019-2024). Highlights so far include potential for Co resources in QLDs NW Minerals Province with metallurgical studies now being conducted to recover Co from pyrite.  Indium, hosted in a range of sulfides, sulfosalts and cassiterite has been recognised in greisen and VHMS mine waste, whilst Sb (and REE) enrichment has been identified in the sampled NT. New investigations are underway to better understand SAs waste with desktop studies suggesting Ni, REEs and Mn fertility. 

 

Whilst these data will ultimately feed into the national Mine Waste Atlas being developed by Geoscience Australia, opportunities to manage the new waste streams are being explored. With new markets coming online seeking feedstocks which are more enviro-ethically sourced. However, the challenge remains, how to ensure policies are in place to support these activities, whilst ensuring that the right technologies to support valorisation are accessible. As global communities align to tackle these hurdles, mine waste transformation looks certain to be the business model of the future. 

  

How to cite: Parbhakar-Fox, A., Jackson, L., Bhowany, K., Blannin, R., Gomes, A., and K'ng, L.: Reimagining Australia's mine waste: New resources, new challenges, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14563, https://doi.org/10.5194/egusphere-egu24-14563, 2024.

16:40–16:50
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EGU24-12537
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ECS
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On-site presentation
Won Jung Ju and Kyoungphile Nam

Sulfide minerals present in mine waste, upon oxidation by oxygen and water, can lower the pH, leading to increased metal solubility. This study focuses on mine waste containing sulfide mineral, utilizing fuel cell technology to recover valuable resources. The aim is to explore the potential conversion of mining by-products into valuable energy and resources, addressing environmental impact and transforming mining waste into a valuable asset. The electrochemical oxidation of pyrite (FeS2) (ΔG0 = -27.15 kJ/mol) is induced through electrode installation, with the reaction facilitated by employing electrodes. In this process, pyrite acts as an electron donor, and oxygen, mediated by the electrode, acts as an electron acceptor. The cathode is designed to induce the oxidation of pyrite (Pyrite→Fe3+), while the anode, exposed to oxygen in the air, promotes the reduction of oxygen (O2→H2O). Pyrite (150-250 μm in diameter) was placed in the anode cell containing 125 mL of anolyte (distilled water adjusted to pH 2.0 with hydrochloric acid), and the cathode cell was exposed to air. After 4 weeks of reaction 23 mg of pyrite was dissolved leaching 0.73 mM of Fe, and generating 4.1616×10−7 W of power. In the further study the fuel cell technology will be applied to utilize sulfidic mining residues (XRD analysis result: FeS1.6Se0.4 42%, FeS2 14%, Mg2CaWO6 12%, etc.), generated during the ore beneficiation process at a tungsten mine in Yeongwol, Gangwon Province, South Korea, for the recovery of energy and valuable metals.

How to cite: Ju, W. J. and Nam, K.: Electrochemical conversion of sulfide mineral-containing mine waste for energy and resource recovery using fuel cell technology, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12537, https://doi.org/10.5194/egusphere-egu24-12537, 2024.

16:50–17:00
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EGU24-17054
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On-site presentation
Petya Gutzmer, Kai Bachmann, Raimon Tolosana-Delgado, Laura Tusa, Cecilia Contreras, Philipp Büttner, and Jens Gutzmer

Reevaluating tailings material originating from a high-sulfidation epithermal gold deposit has unveiled the potential for a holistic remining endeavour. The primary objective of this operation would be the mitigation of minerals containing penalty elements, specifically sulphur in pyrrhotite, a major contributor to acid mine water drainage, alongside the concentration of precious elements like gold. Furthermore, exploring the applicability of the silicate fraction for industries such as ceramics, glass, and geopolymer production has been considered.

To accomplish these objectives, an initial drill core campaign featuring six drill holes was executed, accompanied by a thorough material characterization using automated mineralogy, geochemical assays, and hyperspectral analysis. The subsequent step involved a geometallurgical domaining process based on 64 geochemical assays, particle size measurements, and mineralogy assessments. A Mahalanobis distance hierarchical cluster analysis was employed to differentiate domains, and predictions for these domains were extended to all hyperspectral imaging samples.

The outcome of this comprehensive approach revealed the delineation of four distinct domains, each characterized by variations in modal mineralogy and trace elemental contents. This strategic analysis provides valuable insights into the heterogeneity of the tailings material, laying the groundwork for targeted interventions to address environmental concerns and maximize the extraction of valuable resources.

How to cite: Gutzmer, P., Bachmann, K., Tolosana-Delgado, R., Tusa, L., Contreras, C., Büttner, P., and Gutzmer, J.: Exploration and reevaluation of a tailing storage facility from a high-sulfidation epithermal gold deposit, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17054, https://doi.org/10.5194/egusphere-egu24-17054, 2024.

17:00–17:10
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EGU24-5800
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On-site presentation
Tamara Đorđević, Michael Stöger-Pollach, Sabine Schwarz, Goran Tasev, Todor Serafimovski, Ivan Boev, and Blažo Boev

In the mining waste dumps and tailings of the former As–Sb–Tl–Au Allchar deposit, North Macedonia, secondary oxides and oxy-salt minerals partially control the mobilization of arsenic (As), antimony (Sb) and thallium (Tl). Depending on the pH condition and the proportion of primary sulfide and sulfosalt minerals, we have observed two major scenarios for the retention of As, Sb and Tl through secondary minerals.

We have investigated three dozens of solid samples from the profiles and excavation holes at the three sites of former Alchar mine, analyzed them for their major and minor chemical elements, and characterized them for their mineralogical composition, with a special focus on Tl-secondary minerals at the nano- to centimeter scale.

At the Tl- and As-rich Crven Dol locality, As and Tl dissolved during weathering under circumneutral to slightly alkaline conditions are precipitated as micaceous crystals of poorly crystalline to amorphous thallium arsenates, forming porous aggregates up to 100 µm. These Tl arsenates are intergrown with dolomite and Ca-Fe-arsenates and appear as two different phases. In the first, more common phase Tl:As ratio range from ca. 2.1 to 4.1. In the second, Tl-richer phase, the Tl:As ratio varies from 5.1 to 8.4. In the waste dumps showing acidic pH-values common Tl precipitate is dorallcharite [TlFe3+3(SO4)2(OH)6]. Tl is also accumulated in Mn-oxides (up to 3.6 at.%), pharmacosiderite (up to 0.9 at.%), and jarosite-group minerals (up to 0.9 at.%).

The orpiment-rich tailings are mostly composed of orpiment, quartz, realgar and scorodite, followed by gypsum and kaolinite-group minerals. Realgar and orpiment are the major As-sources and Tl-sulfosalts lorándite, fangite, and raguinite are the primary Tl-sources. The most common Tl-bearing precipitate is dorallcharite mostly embedded in scorodite. Tl is also accumulated in Mn-oxides (up to 5 at.%) and thalliumpharmacosiderite, TlFe4[(AsO4)3(OH)4]·4H2O.

In the deposit is Sb-rich central region, the primary Tl sources are sulfosalts such as fangite, lorándite, and pierrotite, while stibnite is the primary Sb source. Tl dissolved during weathering under circumneutral conditions is reprecipitated as avicennite, Tl2O3, and tiny, fibrous Tl-bearing Mn-oxides (up to 8.5% Tl). Furthermore, tiny spherulitic aggregates (up to 3 µm) of a Tl-Sb-oxide (a new mineral species) have been found intergrown with quartz, muscovite, and minor dolomite. TEM-based EBSD on Tl-Sb-oxide particles confirmed that the Tl-Sb-oxide is crystalline, and EDS-line and area scans confirmed a Tl:Sb ratio of 2.5, indicating that Tl enters the crystal structure of the new Tl-Sb oxides rather than being hosted in the nanophase.The oxidative weathering of Tl-bearing metal-sulfides generates both nano- and microcrystalline Tl-minerals.

Our future investigation focuses on the formation and dissolution of these phases and will offer a much deeper understanding of the mechanisms of mineral association formation.

Financial support of the Austrian Science Fund (FWF) [P 36828-N] is gratefully acknowledged.

How to cite: Đorđević, T., Stöger-Pollach, M., Schwarz, S., Tasev, G., Serafimovski, T., Boev, I., and Boev, B.: Macro- to nanoscale mineral relationships in mining wastes of the As–Sb–Tl–Au Allchar mine, North Macedonia, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5800, https://doi.org/10.5194/egusphere-egu24-5800, 2024.

17:10–17:20
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EGU24-2202
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Highlight
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On-site presentation
Pedro Riesgo Fernández, Alicja Krzemień, Gregorio Fidalgo Valverde, Antonio Luis Marqués Sierra, and Francisco Javier Iglesias Rodríguez

This presentation introduces the Research Fund for Coal and Steel (RFCS) GreenJOBS project, which approach is premised on leveraging five competitive advantages of underground coal mines to deploy emerging renewable energy and circular economy technologies:

(1) mine water for geothermal and green hydrogen. Geothermal energy is a renewable source that harnesses the heat from inside the earth, in our case, through the water that floods the mines. From a certain depth, the temperature of the subsoil is constant regardless of the season. Thus, a continuous and accessible energy source is available all year round. On the other hand, mine water represents an essential raw material for producing green hydrogen by electrolysis;

(2) connections to the grid that can be adapted to inject the electricity produced;

(3) large waste heap areas for installing photovoltaic/wind;

(4) deep shafts suitable for unconventional pumped hydro storage using dense fluids that has a smaller footprint and higher energy density than conventional pumped hydro energy systems; and

(5) fine coal waste for recycling into dense fluids employed by the unconventional pumped hydro storage; artificial substitutes for soils from coal waste and wastes from closely located agricultural industries, coal-fired power plants, and water plants; and rare earths from fine coal wastes.

The objective is to provide mining companies with two innovative business plans: a Virtual Power Plant where the energy produced will be sold to the grid or used to power electro-intensive industries or companies with constant energy consumption located close to mines, such as aluminium factories or green data centres; and a Green Hydrogen Plant where renewable hydrogen will be produced by electrolysis of mine water and electricity from renewable sources.

How to cite: Riesgo Fernández, P., Krzemień, A., Fidalgo Valverde, G., Marqués Sierra, A. L., and Iglesias Rodríguez, F. J.: Repurposing former underground coal mines by deploying emerging renewable energy and circular economy technologies, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-2202, https://doi.org/10.5194/egusphere-egu24-2202, 2024.

17:20–17:30
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EGU24-3065
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Highlight
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On-site presentation
Moncef Bouaziz, Bejamin Haske, Marwan Al Heib, and Joerg Benndorf

Abandoned mines are generally exposed to multi-hazard: natural and man-mad hazards. The risk assessment is one of the challenges of the site management. This paper presents first the categories of hazards and potential interactions, then it shows a Geographical Information System (GIS)-based Decision Support System (DSS), as part of the European research project titled "POst-mining Multi-Hazards Multi-Assessment for Land-Planning (POMHAZ)." Utilizing predominantly open-source tools (PostGIS, Geoserver, and Leaflet) and Python Scripts, the DSS aims to tackle the intricate challenges posed by post-mining hazards in European mining regions. The objective is to furnish a functional web-based tool tailored for EU administrative units, ensuring a comprehensive evaluation of various hazards that impact their territories.

In the context of post-mining landscapes, conventional environmental policies often encounter challenges due to the lack of operational and accessible tools. The proposed DSS seeks to bridge this gap by catering to a diverse user base, including citizens, scholars, associations, and public bodies.

The DSS streamlines the acquisition, management, and processing of both static and dynamic data, providing web-accessible data visualization. Customized for post-mining multi-hazards, this tool contributes to enhanced decision-making by generating data, statistics, reports, and maps for various EU areas of interest. Validation is obtained through a case study of abandoned coal mine (France), this validation demonstrates its capabilities. This paper showcases the practical application of the DSS in North Rhine Westphalia offering valuable insights to address the intricate challenges posed by post-mining hazards.

How to cite: Bouaziz, M., Haske, B., Al Heib, M., and Benndorf, J.: A GIS-Based Decision Support System for Multi-Hazard Assessment in Post-Mining Regions, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-3065, https://doi.org/10.5194/egusphere-egu24-3065, 2024.

17:30–17:40
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EGU24-7632
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ECS
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Highlight
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On-site presentation
Christian Frigaard Rasmussen, Christian Juncher Jørgensen, Jens Søndergaard, and Anders Mosbech

As the world’s need for raw materials increases, more mines are planned to be established in the Arctic. The Arctic provides a unique and challenging environment for mining operations and introduces concerns for the potential spread of pollution. Arctic environmental conditions linked to wind- and waterborne pollution transport such as hydrology, precipitation, temperature, windspeed and wind direction vary markedly throughout the year and the environment is sensitive to anthropogenic influence.

In Greenland, several legacy mines provide testimony to how pollution still affects the sensitive Arctic environment. These legacy mines serve as valuable study sites that can improve future predictions on environmental consequences of mining operations in Greenland and other areas in the Arctic. Environmental studies at legacy mine sites in Greenland have previously focused on the leaching of pollutants into the marine environment and little is known about the spatial distribution of pollution in the terrestrial environment at these sites.

In the current study, we present preliminary data from an environmental survey at the Blyklippen legacy mine. Blyklippen was a lead and zinc mine in East Greenland that operated between 1956-1963. Mining operations caused substantial pollution of lead (Pb), zinc (Zn), and other heavy minerals such as cadmium (Cd), barium (Ba) and copper (Cu), still measurable today. The primary sources of pollution today are the tailings storage facility and remains of ore concentrate spills along the haul road and at the quay areas at the harbor. Pollution is dispersed from these sites into the surrounding environment by wind and water.

The aim of the current study is to investigate and map the spatial distribution of heavy metals in the environment surrounding the Blyklippen legacy mine using both field measurements by portable X-Ray Fluorescence spectrometry (pXRF) on depth specific sediment samples at in situ conditions and laboratory measurements on freeze-dried samples to investigate the effect of soil moisture on the accuracy of the field screening. Field measurements were conducted using short measurement times of 5-10 seconds, whereas laboratory measurement times were 180 seconds.

A total number of 995 discrete sediment samples were collected over 10 days at the Blyklippen mine site and surrounding area of Mestersvig from 178 sampling locations at depth intervals of 5 cm. Our results demonstrate the effectiveness of pXRF as a field measurement tool for identifying the spatial delineation of soil pollution by comparing in situ measurements against pre-defined natural background values for heavy metals such as Pb and Zn. Comparison between Pb and Zn concentrations measured in the field versus in the laboratory on freeze-dried samples showed a good agreement for mineral soils. On organic and/or wet samples, field concentrations were underestimated for some elements.

Overall, the approach shows that a fast and cost-effective large-scale field survey at legacy mines is obtainable using pXRF, enabling an effective identification of pollution ‘hotspots’ directly in the field. In combination with geostatistical mapping, the approach can improve the overall accuracy of environmental monitoring and mapping of pollution with enhanced environmental protection at both legacy, recent and future mines.

How to cite: Rasmussen, C. F., Juncher Jørgensen, C., Søndergaard, J., and Mosbech, A.: Environmental monitoring of pollution at legacy mines in Greenland using portable X-ray Fluorescence Spectrometry (pXRF), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7632, https://doi.org/10.5194/egusphere-egu24-7632, 2024.

17:40–17:50
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EGU24-20831
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Virtual presentation
Violetta Sokoła-Szewioła, Zbigniew Siejka, and Patrycja Jarczyk

The period of coal mine closures can be accompanied by many hazards, including the post-mining seismic hazard. Seismic phenomena, particularly during mine flooding, are felt by people, can cause minor or severe damage to buildings and affect shallow mine workings, and can cause reactivation of shallow mine workings in the form of sinkholes or other discontinuous deformations. It is therefore important to deepen the knowledge concerning these phenomena, particularly their relationship to surface deformations. This issue was the subject of a European research project with the acronym PostMinQuake financed by the Research Fund for Coal and Steel in 2020- 2023 (Grant Agreement No: 899192). The project involved the study of surface deformation in relation to registered post-mining earthquakes during the flooding of the Kazimierz- Juliusz coal mine. The research area was located in Poland in the area of the Upper Silesian Coal Basin. In this area, continuous monitoring of surface deformation was carried out for more than 2 years on single observation points using GNSS technology. The monitoring was carried out using an automatic GNSS monitoring system developed in the project. 

The paper presents the results of an analysis of the course of changes in vertical displacements at the above-mentioned points, in relation to the post-mining earthquakes registered during the study period. The analysis showed that in the case of more than 58% of the analyzed phenomena in the course of vertical displacements in the period associated with the occurrence of the post-mining earthquake, there were some regularities in the course of these displacements. It was found that, an increased uplift was observed prior to the occurrence of the event, in the next period of time, after the occurrence of the event, an increased increment in subsidence was generally observed, after that period, stabilization of the changes in vertical displacements was observed, as well as a slow increment of subsidence and/or the increment of uplifts. On this basis, it was concluded that there was a relationship between the observed course of displacements and the occurrence of post-mining earthquake. It was assumed that the significant increase in observed uplift can be a predictor of the occurrence of a post-mining earthquake.

 

How to cite: Sokoła-Szewioła, V., Siejka, Z., and Jarczyk, P.: Post-mining earthquakes and changes in observed vertical ground displacements during the period of mine flooding , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20831, https://doi.org/10.5194/egusphere-egu24-20831, 2024.

17:50–18:00
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EGU24-17569
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On-site presentation
Michail Galetakis, Emmanouil Varouchakis, Christos Roumpos, and Georgios Louloudis

Ecological reclamation of mined areas is a critical step in restoring environmental balance. Mining companies and operators are usually required to restore their sites to a condition that supports an agreed post-mining land use and to mitigate environmental and social impacts. To achieve rehabilitation approval, specific closure objectives and completion criteria must be defined to determine whether the necessary outcomes have been attained.  Certifications in this area typically focus on ensuring that reclamation processes meet certain standards and effectively restore the ecosystem. Some well-known certifications include the Society for Ecological Restoration (SER) certification and the International Standards Organisation (ISO) environmental management system certification. SER certification often assesses projects based on ecological integrity, historical and cultural considerations, and sustainable management. It ensures that reclamation efforts promote biodiversity, soil health and overall ecosystem resilience. On the other hand, older ISO certifications, particularly ISO 14001, focus on environmental management systems and ISO 26000 on social responsibility. While not specific to ecological reclamation, it provides a framework for organisations to develop and implement environmentally responsible practices. Recent ISO standards like 21795:2021 specify the framework and the processes involved in mine closure and reclamation planning for new and operating mines, and they also provide requirements and recommendations.  These certifications play a critical role in establishing credibility and ensuring that ecological reclamation efforts meet recognised standards. They also contribute to the broader goal of sustainable mining practices. This study examines the evolution of standards for the certification of rehabilitation of mined sites, reflecting the growing awareness of environmental impact and the shift toward sustainable practices.

How to cite: Galetakis, M., Varouchakis, E., Roumpos, C., and Louloudis, G.: Certification systems for the ecological rehabilitation of mined areas, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17569, https://doi.org/10.5194/egusphere-egu24-17569, 2024.

Posters on site: Thu, 18 Apr, 10:45–12:30 | Hall X4

Display time: Thu, 18 Apr 08:30–Thu, 18 Apr 12:30
Chairpersons: AL HEIB Marwan, Hernan Flores
X4.191
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EGU24-5645
Feven Desta, Oscar Kamps, and Mike Buxton

The ever-growing demand for mining products has led to the extraction and processing of large volumes of materials, resulting in the production of significant amounts of mine waste. While the composition of mine waste materials can vary and may cause environmental impacts, they can also be a valuable source of raw materials to meet the current and future mineral demand. The efficient re-mining of minerals of economic interest from mine waste materials (such as slag) requires accurate and reliable estimation. This can be achieved using state-of-the-art sensor technologies coupled with advanced data analytics. Such technologies include laser-induced breakdown spectroscopy (LIBS), x-ray fluorescence (XRF), short-wave infrared (SWIR) and Fourier transform infrared spectroscopy (FTIR). This study evaluates the usability of LIBS, FTIR, SWIR, and XRF technologies for the characterization of Ferronickel slag materials at a multi-level. Methodological approaches were developed to assess the usability of each technique for the identification, classification, or semi-quantification of the target elements (such as Ni, Ti, Pb, and Cr) in the analyzed samples. The results demonstrate that the use of the techniques enabled a comprehensive compositional analysis of slag materials. Moreover, the findings suggest that such an approach could promote sustainable mining practices by providing valuable insights into the potential economic benefits of reusing slag materials for secondary recovery. Such an approach could contribute to reducing the possible environmental impact of waste and could enable achieving a circular economy.

How to cite: Desta, F., Kamps, O., and Buxton, M.: Sensor-based Multi-Level Analysis of Ferronickel Furnace Slag: Exploring Economic Opportunities   , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5645, https://doi.org/10.5194/egusphere-egu24-5645, 2024.

X4.192
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EGU24-19060
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ECS
Mateusz Wolszczak, Anna Potysz, and Grzegorz Lis

Biohydrometallurgy is known as one of techniques of beneficiation of metal ores, utilizing microorganism activity to enhance the extraction of metal ions from ore minerals. The method is widely known from its economic and environmental advantages in comparison to other beneficiation methods, i.e. pyrometallurgy. The development of biohydrometallurgy applications for the mining industry has continued since the eighties when several bioleach operations for low-grade copper ores and refractory gold concentrates have been commissioned. Although significant extraction rate, biological-induced leaching does not constitute main processing technique due to economic reasons, what drive researchers to searching novel ways to enhance the efficiency of metal recovery.

 

This research came with the idea of improving the efficiency of metal bioleaching by presence of dispersed organic matter naturally occurring in some rocks. Main hypothesis of the research assumes using dispersed organic matter as a source of organic carbon by heterotrophic bacteria that could further enhance dissolution of ore minerals. The idea came from both facts: consumption and metabolic utilization of dispersed organic matter by heterotrophic microorganisms and influence of consumed organic compounds on microbial activity e.g. secretion of siderophores (metal chelating compounds, crucial for solubilization metal ions and thus acceleration the metal leaching).

 

The examined rock is metalliferous-bearing shale enriched in dispersed organic matter (with average TOC parameter from few to even 30 wt.%). Two shale samples different in their metal and organic matter quantity were chosen for testing the hypothesis. The potential of black shale for bioleaching was examined through series of incubation experiments. Different experiment conditions were applied, involving both autotrophic (Acidithiobacillus thiooxidans) and heterotrophic (Pseudomonas fluorescens) bacteria and different medium compositions (with presence and absence of organic nutrient in particular).

 

The incubation experiment took place in a shaker incubator at a controlled temperatures for a period of five weeks. After the incubation experiment the leachates were collected and analyzed for the concentrations of eight metals: copper, lead, zinc, molybdenum, arsenic, nickel, cobalt and vanadium. The metal recovery percent features variation depending on shale sample, specific metal, and incubation condition. The highest metal recovery was achieved for heterotrophic bacterium in case of copper and molybdenum and for autotrophic one in case of arsenic, while rest of metals showed insignificant recovery. Lack of organic nutrients weakened the activity of P. fluorescens compared to bacterium supplied with organic nutrient, however metal leaching was still maintained.

How to cite: Wolszczak, M., Potysz, A., and Lis, G.: The bioleaching of metals from organic-rich black shale by Pseudomonas fluorescens, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19060, https://doi.org/10.5194/egusphere-egu24-19060, 2024.

X4.193
|
EGU24-20090
|
ECS
|
Shane Aulestia, Jasmina Toromanovic, and Jan Laue

Suffusion is an internal erosion mechanism observed in embankment dams, caused by washing out fine-grained particles within the dam core as a consequence of seepage with various hydraulic gradients. The initiation of internal erosion is conditional upon three primary factors: grain size distribution, stress conditions, and hydraulic gradient. Graded moraines, such as glacial tills, exhibit an increased susceptibility to suffusion when compared to other soil types used in dam construction. Many Swedish embankment dams in mining and hydropower industry were constructed with glacial till cores over 50 years ago, lacking specific guidelines related to grain size boundaries for core and filter materials. This deficiency has given rise to instances of internal erosion, therefore elevating safety concerns.

Previous research aimed to enhance dam safety by exploring the susceptibility of glacial till soils to suffusion. Silva (2022) reviewed existing methods for assessing soil susceptibility, comparing testing conditions, and presents an experimental study on critical hydraulic gradients for suffusion initiation in glacial till soils. Results indicate the critical hydraulic gradient depends upon testing conditions, including axial loading, the rate of gradient increase, and time intervals. Furthermore, it underscores the efficacy of Kenney and Lau (1985, 1986) method for assessing suffusion susceptibility. These insights offer valuable contributions to the assessment and mitigation of internal erosion in embankment dams, thereby addressing a significant safety concern within the Swedish dams infrastructure.

Silva (2022) has offered valuable insights into suffusion phenomena while the intricacies of erosion processes remain unclear, hindering the implementation of rehabilitation measures to ensure the longevity of embankment dams. A follow-up project utilizing the advantages of transparent soil seeks to further comprehend the migration of fines within a soil matrix. Transparent soils, emerging as a viable alternative with likely properties to sand and clays, consist of a two-phase medium by refractive index allow solids to represent the soil skeleton and a fluid solution to mimic pore fluids. Various solids, such as amorphous silica, silica gel, hydrogel, fused quartz, and laponite, have been employed in conjunction with fluid solutions, depending on the solid, as mineral oil and paraffinic solvent, calcium bromide brine, sucrose solution, or water.

Transparent soils offer the potential to replicate the behavior of glacial till cores employed in embankments, particularly those designed for the storage of tailings material in the mining industry, and water retention for hydropower. The applicability of these findings may address and enhance rehabilitation measures in such structures, which are imperative to mitigate potential socio-economic and environmental ramifications in the event of failure. Given the escalating global demand for mining resources and renewable energy, proactive measures are essential to predict long-term issues looking for a more sustainable and efficient construction methodologies to extend infrastructure lifespans.

How to cite: Aulestia, S., Toromanovic, J., and Laue, J.: Towards migration of fines within a soil matrix, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20090, https://doi.org/10.5194/egusphere-egu24-20090, 2024.

X4.194
|
EGU24-17315
Soraya Heuss-Aßbichler, Laddu Bhagya Jayasinghe, Alireza Sobouti, Iman Dorri, and Juan Antonio Munizaga-Plaza

The increasing demand for raw materials in our society and the requirements for supply security in particular regarding the critical raw materials require the implementation of sustainable resource management in the sense of the best possible conservation of natural resources as well as the promotion of recycling and recovery of valuable materials from waste. In the mining sector, classification systems like CRIRSCO were introduced to communicate the viability of projects. In the realm of resource classification, the United Nations Framework Classification of Resources (UNFC) stands as a crucial tool, offering a principles-based approach to classifying the viability of any kind of resource development projects including renewable energy or groundwater. By systematically classifying projects based on their environmental, socio-economic, and technical aspects, the UNFC provides decision-makers with valuable insights for making choices regarding their viability and offers the opportunity to take sustainability aspects into account. A consistent evaluation and classification of projects according to the same premises as for primary raw materials can significantly contribute to the efficiency of initiatives for the recovery and recycling of secondary raw materials including mining waste. There is a Guidance[1] for the Application of the United Nations Framework Classification for Resources (UNFC) for Mineral and Anthropogenic Resources in Europe. However, it doesn’t include end-of-life products as anthropogenic resources. There are also no instructions on how to evaluate and classify SRM projects.

To bridge the gap, our focus has centered on the development of a web-based tool explicitly designed for the assessment of SRM recovery projects in line with the principles of the UNFC. A seven-stage approach was developed to streamline the evaluation process and by that, improve the accessibility and applicability of the classification system. Its design, features, and functionalities are tailored to ensure a user-friendly interface. Users are guided from the outset by defining the project and its systems boundaries, formulating the project’s objective and the context of evaluation, including the choice of the controlling factors, to carry out a thorough analysis of SRMs and thus align their initiatives with the principles of the UNFC. At the end, a template is available for reporting.

This poster presentation aims to emphasize the versatility and effectiveness of our web-based tool through a practical example, using a publication developed to classify a tailings storage facility in Germany. Through an interactive demonstration, the user-friendly interface, the power of customizable inputs, and the seven coordinated steps that guide users in assessing the feasibility and viability of secondary raw material projects will be discussed. Attendees will gain a deeper understanding of how the tool facilitates informed decision-making by providing a systematic approach to evaluating projects involving secondary raw materials, aligning with the principles of the UNFC.


[1] https://unece.org/sites/default/files/2022-11/UNFC%20GUIDANCE%20EUROPE-FINAL.pdf

How to cite: Heuss-Aßbichler, S., Jayasinghe, L. B., Sobouti, A., Dorri, I., and Munizaga-Plaza, J. A.: A Web-Based Tool for Assessing Sustainability in Secondary Raw Material Recovery Projects Using the UNFC Framework, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17315, https://doi.org/10.5194/egusphere-egu24-17315, 2024.

X4.195
|
EGU24-8042
|
ECS
Rafael León Cortegano, Francisco Macías, Carlos R. Cánovas, Rafael Pérez-López, Ricardo Millán-Becerro, Jonatan Romero-Matos, Laura Sánchez-López, and José Miguel Nieto

The Iberian Pyrite Belt (IPB), located in the SW of the Iberian Peninsula, is one of the largest polymetallic massive sulfide provinces in the world. Historical mining activity in the area has left a significant legacy of mine residues, including 90 abandoned mines and more than 1.000 ha of waste rock dumps and tailings. Therefore, large volumes of Acid Mine Drainage (AMD) are produced due to oxidation of pyrite-rich residues exposed to atmospheric conditions, which end up in the Tinto and Odiel rivers and subsequently into the ‘‘Ría de Huelva’’ estuary (SW Spain), polluting these water environments. During the passive treatment of AMD with Dispersed Alkaline Substrate (DAS) technology, sequential precipitation of Fe3+ as schwertmannite and Al as basaluminite occurs, and Rare Earth Elements (REE) are preferentially concentrated within the Al-rich precipitate layer. This could be an interesting alternative source of REE, given that AMDs of the IPB are enriched in middle REE (MREE) and heavy REE (HREE). A rough estimation of the REE potential of these AMD sources, based on 40 DAS plants operating in the Odiel basin with variable content of REE, will be the production of 11 kton/year of basaluminite containing 21 ton/year of REE2O3 with grade of 0.19%. However, the origin of REE in AMD is not well understood. This work examines the concentration and pattern of REE in AMD, ore bodies, and country rocks in two representative mining areas of the IPB: Perrunal and Poderosa mines. Leaching experiments were conducted on sulfide ores and host rocks under simulated AMD formation conditions, and the results were compared with the AMD formed in these two mining areas. The preliminary results indicate that the host rocks (felsic and mafic volcanics and shales) are the primary source of REE in the AMD. A mineralogical and chemical study of the country rocks in Perrunal and Poderosa mines reveals that secondary phosphates and carbonates contain the highest REE content, which are also soluble under acidic conditions. REE-rich monazite-type is systematically present in felsic volcanics and shales in both mining areas. HREE-rich xenotime-type is also present in most felsic volcanics, while REE-rich carbonates (mainly parasite-type) are present in carbonate-rich shales from the Perrunal mine. Other minor REE-bearing minerals, such as apatite and zircon, have been identified in the host rocks. However, due to their lower abundance and solubility under acidic conditions, they are not considered an important source of REE in the AMDs of the studied mining areas. Finally, the petrographic evidence shows a selective leaching of these REE-bearing phosphates and carbonates which highly supports their involvement as the main source of REE in AMD.

Acknowledgements: This work is part of the I+D+i TRAMPA project (PID2020-119196RB-C21), funded by MCIN/AEI/10.13039/501100011033/.

How to cite: León Cortegano, R., Macías, F., R. Cánovas, C., Pérez-López, R., Millán-Becerro, R., Romero-Matos, J., Sánchez-López, L., and Nieto, J. M.: Origin of Rare Earth Elements in Acid Mine Drainage: Mineralogical Insights from the Iberian Pyrite Belt (SW Spain), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8042, https://doi.org/10.5194/egusphere-egu24-8042, 2024.

X4.196
|
EGU24-9303
Giulio Galamini, Daniele Malferrari, Fabiana Altimari, Silvia Orlandi, and Luisa Barbieri

Zinc (Zn) is a crucial micronutrient for plants, related with tolerance against diseases. When crop demand exceeds Zn availability in the soil, using Zn­-fertilizers becomes necessary (biofortication), however, even in foliar application, soluble Zn salts are mostly used, which are prone to leaching and consequently exhibit limited uptake by plants.

In response to this challenge, a novel controlled-release formulation, utilizing mine wastes as carrier, was developed, involving an energy-efficient process with ambient temperature and pressure, and a reaction time of approximately 8 hours.

Formulations were prepared by mixing a zeolite-rich (clinoptilolite) tuff with 2 quarry by-products, namely lapillus and pumice, using different dosages. We conducted studies on the kinetics of Zn adsorption and release, ultimately identifying the most effective mixture which comprised 70% zeolite-rich tuff and 30% pumice.

To assess the effectiveness, a fertilization test was performed via foliar application in Vitis vinifera, aiming to evaluate the Zn coverage, and the persistence of the product against simulated rainfall, in comparison with conventional ZnSO4 fertilizer.

The test confirmed greater Zn resistance to rain leaching, also suggesting potential for reducing treatment dosages, thereby mitigating environmental-related impacts. Moreover, the presence of 30% pumice would allow significative reuse of mining byproduct.

Project funded under the PNRR–M4C2INV1.5, NextGenerationEU-Avviso 3277/2021 -ECS_00000033-ECOSISTER-spk1

 

How to cite: Galamini, G., Malferrari, D., Altimari, F., Orlandi, S., and Barbieri, L.: Recycle of quarry byproducts for producing a new Zn fertilizer, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-9303, https://doi.org/10.5194/egusphere-egu24-9303, 2024.

X4.197
|
EGU24-7755
|
ECS
Marco Casale, Francesca Gambino, Alessandro Borghi, Riccardo Beltramo, Enrica Vesce, Cristina Varì, Marco Giardino, and Giovanna Antonella Dino

Every mining activity has a footprint on the territory. The signs left by mining operations are physical, such as tunnels, extractive waste facilities, dressing plants, but also economic and social, because the mine generates employment, income and knowledge.

The signs left by mining operations are tangible (presence of tunnels, extractive waste facilities, dressing plants, etc..) and cause environmental, social and economic impacts, in terms of employment, income, knowledge, potential risks (if not well managed and monitored).

In the extraordinary context of the Germanasca Valley, mining has coexisted for hundreds of years with the mountain environment of the Alps and with the local population and has become a fundamental part, intimately connected with the territory and with the local economic and social fabric.

The progressive migration of mining activity at lower altitudes has left behind old mining structures that here, more than elsewhere, they have been able to adapt, at least in part, for the benefit of new forms of industrial and geo-tourism.

Similarly, the technological advance and the evolution of mining production, towards a higher quality product, with a consequent reduction in the quantities exploited has led over time to a progressive reduction in the number of miners employed.

The resilience of the local population, however, has allowed to absorb the contraction of work in the mine transforming former miners in tourist guides and increasing the activities induced, passing from the previous model "in house" to an “outsourcing” model, where many mine-related activities are outsourced.

The transformation of old mines into museums has certainly contributed to the development of the area, particularly considering a rediscovery tourism that has little to do with the "fast and junk" tourism that has grown lately. The challenge is to understand how much weight geo-tourism, in the specific case of mining, has on the attractiveness of a place, starting with the concrete example of Germanasca Valley.

The investigated area can be recognised as a case study to analyse the close connection between still active mining activity and territorial development, associated both to mineral production and geo-tourism.

 

KEY WORDS

Sustainable mining, post-mining, industrial tourism, geo-tourism, mining tourism, talc.

How to cite: Casale, M., Gambino, F., Borghi, A., Beltramo, R., Vesce, E., Varì, C., Giardino, M., and Dino, G. A.: A sustainable integration of mining activity and geo-tourism: a case study in Northern Italy., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7755, https://doi.org/10.5194/egusphere-egu24-7755, 2024.

X4.198
|
EGU24-3665
|
ECS
Management of rockburst risks in deep underground engineering through controlled contour blasting
(withdrawn)
Ang Lu, Peng Yan, Wenbo Lu, Xiaofeng Li, and Yuan Cao
X4.199
|
EGU24-10941
Evangelos Machairas, Emmanouil Varouchakis, and Michail Galetakis

Cost Benefit & Bayesian Analysis for Mining Waste Management contributes positively to developing an alternative methodology that could be implemented on an industrial scale. Two case scenarios are examined. The first scenario refers to the presentation of mining activities without 3R’s policy (reduce, recover, reuse wastes) and non-implementation of environmental protection measures. The second scenario refers to the presentation of mining activities with full implementation of environmental protection requirements by a closed system of industrial units for metal recovery and avoiding free disposal of tailings in soil areas. Considering a) each project’s aim and scope, b) legislative requirements for environmental protection, and c) escalation of penalty cost for non-compliance with the corresponding legislation, the total cost for each case scenario is extracted. Cost-benefit analysis (CBA) evaluates the sustainability of each case scenario by its Financial Risk.

The scope of this paper is to ensure the adaptability of the CBA appraisal tool to each similar subject of study, in which the lowest Financial Risk indices characterize optimal business decisions. CBA’s evaluation involves each case scenario’s parameters converted into monetary terms. CBA’s extracted results are calibrated through Bayesian Analysis to provide more accurate Financial Risk (FR) estimation. The physical meaning of Bayesian Analysis’s provided calibration to the CBA is to obtain the ability to implement stochastic risk in realistic conditions.

How to cite: Machairas, E., Varouchakis, E., and Galetakis, M.: Cost – Benefit Analysis through Stochastic Risk Assessment on Mining Waste Management, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10941, https://doi.org/10.5194/egusphere-egu24-10941, 2024.

X4.200
|
EGU24-3957
|
ECS
Chenxu Su, Nahyan M. Rana, Stephen G. Evans, Bijiao Wang, and Shuai Zhang

The historical failures of Tailings Storage Facilities (TSFs) in China have led to severe downstream consequences, encompassing loss of life, economic damage, and environmental contamination. Despite these consequences, the comprehensive documentation and quantitative evaluation of TSFs in China have been notably lacking. The existing records of TSFs are incomplete, and there is a deficiency in accurately assessing the frequency of their failures. This gap in knowledge has been a significant obstacle in effectively assessing and mitigating risks associated with TSFs. Our research involved compiling and analyzing new databases, shedding light on the historical failures and current status of TSFs in China. We uncovered 143 TSF failure incidents between 1957 and 2022. This figure largely exceeds the approximately 20 failures reported in earlier studies, highlighting a critical underestimation in past assessments. The human and economic damage of these incidents has been considerable, with 840 lives lost, 1,416 houses damaged, and 28,923 individuals adversely affected. Furthermore, the total volume of tailings released in these failures surpassed 12.7 million m3. A notable observation from our study is that about 75% of these failures involved tailings flowing into water bodies, exacerbating environmental pollution significantly. Our study also presents an in-depth statistical analysis of the magnitude and frequency of these failures. We found that the average return period for TSF failures in China, resulting in at least 10 fatalities, is approximately every five years. For failures with released volumes exceeding 1 million m3, the average return period extends to about 16 years. In addition to historical data, we include a comprehensive review of current TSFs. Our review confirms that there are 14,217 existing TSFs in China alone, leading to an estimated cumulative failure rate of approximately 1%. Our work further includes the development of a supplementary database encompassing 1,853 TSFs, providing essential statistics such as storage volume and dam height. This database is a crucial tool for ongoing and future risk assessments. Applying our database-driven, regionally-simplified risk assessment approach, we conducted a case study in Jilin Province. The results are concerning, indicating 11 TSFs bearing intolerable risks, among which the most hazardous TSF presents a potential loss of life estimated at 175 individuals. Our study offers the most comprehensive overview of TSF failures and their implications in China to date. The extensive scope of this research bears substantial implications for prospective nationwide utilization, particularly in the enhancement of risk assessment methodologies and the enforcement of efficacious mitigation measures for TSFs in China.

How to cite: Su, C., Rana, N. M., Evans, S. G., Wang, B., and Zhang, S.: Comprehensive analysis and risk assessment of tailings storage facilities in China , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-3957, https://doi.org/10.5194/egusphere-egu24-3957, 2024.

X4.201
|
EGU24-11299
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ECS
Yin Jeh Ngui, Adrian White, Harry Harrison, Judith Porter, James Boyd, Phil Meldrum, Paul Wilkinson, Oliver Kuras, Jonathan Chambers, and Sam Deeley

Disused coal tips formed by waste materials from coal mining activities can become unstable over time. Landslides or avalanches of coal waste can occur, especially during heavy rainfall or by other environmental factors, leading to significant safety hazards for nearby residents and infrastructure. The Welsh Government Coal Tip Safety Taskforce has recently identified over 2,500 disused coal tips in Wales potentially posing a risk, following a significant landslip in Tylorstown after the 2020 storms. Ongoing climate change further destabilises these legacies of past mining activities, posing great challenges to land management and hazard remediation, as instability within the coal tip can be invisible to surface surveys and inspections.

Wattstown in the Rhondda Cynon Taf County Borough was identified as a preferred location for deploying long-term 4D geoelectrical monitoring, with the aim of observing the moisture dynamics between a heavily vegetated basin area upslope of the coal tip (where a previous landslip has occurred) and the downslope tip materials. A BGS-designed Proactive Infrastructure Monitoring & Evaluation (PRIME) system has been deployed here to characterise this site using eight 32-electrode arrays. PRIME is a low-cost, low-power, non-invasive 4D geo-electrical imaging technology designed for near-real-time infrastructure monitoring.  The eight ERT sensor arrays are arranged so that four arrays form two long 2D survey lines to monitor the main slope in directions perpendicular to each other, while a further five arrays cover the landslip region in a 3D configuration, in which one of the arrays is common between the linear and the grid configuration. A full daily measurement schedule allowing for ground motion tracking has been implemented since Mid-2023. Measured data is transferred daily to the BGS servers, and system diagnostics reports are automatically generated to confirm the recent monitoring status and performance of the PRIME system.

The baseline resistivity model shows a lower resistivity layer with a variable thickness of 0 - 5 m covering the whole monitored area. This layer is interpreted as spoils that have been deposited and subsequently reprofiled. Our observation also matches with the presence of high clay contents found in the hand-augered soil. Below the reprofiled spoils resistivity values increase significantly, likely to be underlying bedrock that is composed of sandstone with interbedded layers of coal and silt.

Time-lapse inversion revealed the influence of effective precipitation on the moisture dynamics of the coal tip. Several anomalies were observed within the gradually decreasing resistivity distribution in the near-surface. Along the line perpendicular to the slope, larger low-resistivity features are observed in both the ditches that run parallel to the slope. This could be the result of preferential infiltration in these areas and the ponding of surface water. In the rotational landslip area, PRIME monitoring data has identified what is potentially a preferential flow path from 5 m to 10 m below ground level.

Through continuous monitoring of the disused coal tip, the PRIME system demonstrated its capability for enhanced coal tip assessment, detecting critical hydrogeological processes through minimally-invasive subsurface imaging. Ongoing work aims to establish in-situ petrophysical relationships.

How to cite: Ngui, Y. J., White, A., Harrison, H., Porter, J., Boyd, J., Meldrum, P., Wilkinson, P., Kuras, O., Chambers, J., and Deeley, S.: Developing PRIME Technology for Enhanced Coal Tip Assessment: Innovations in Continuous Geoelectrical Monitoring and Landslide Decision Support, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11299, https://doi.org/10.5194/egusphere-egu24-11299, 2024.

X4.202
|
EGU24-14982
|
Highlight
Natalia Walerysiak, Jan Blachowski, Jarosław Wajs, and Paulina Kujawa

Post-mining areas require constant monitoring due to the risk of secondary ground movements of a continuous or discontinuous nature. This study focuses on the analysis of ground movements in the post-mining area of the “Babina” mine in Western Poland. The complex nature of the “Muskau Arch” glaciotectonic area, subjected to both underground and open pit mining, further complicates the understanding and monitoring of these movements.

The study site was subjected to precise levelling monitoring between 2020 and 2023, and the results of five measurement campaigns form the basis of the analysis, with the first measurement being the reference for the subsequent ones. For this purpose, a geodetic monitoring network was established to cover key locations in the “Babina” mine area. The network was made up of 99 control points set-up as concrete pillars with metal control bolts and was connected to 4 reference benchmarks of the national levelling network situated beyond the post-mining area. In addition, 7 local research networks have been established in specific study sites. The levelling measurements were carried out using geodetic precision levelling. The total length of the levelling lines was approximately 36 km. The ground movements recorded between the first (initial), carried out in May 2020, and the last measurement campaign, in September 2023, range from -5.58 mm to +4.97 mm. Ground movements in the specific dense networks range from -39.46 mm to +115.39 mm.

Three interpolation methods were used to obtain continuous maps of the ground movements from discrete levelling observations: Inverse Distance Weighted, Radial Basis Function and Ordinary Kriging. The latter technique produced the smallest root-mean-square errors assessed with the cross-validation technique. In the result, we obtained 24 maps representing elevation changes between the first and the last measurement, as well as maps representing movements between consecutive measurements.

The maps of ground movements were used to identify areas of statistically significant displacements and to analyse the evolution of these displacements over time and in relation to the extent of past underground and open-pit mining activities and current land use. The results indicate present-day activity of the ground in the post-mining area that varies in the magnitude and direction of movements in different parts of this complex area. The observed seasonal fluctuations may indicate relationship of benchmark movements with periodic change of ground water level and the effect of climate change.

Our findings confirm the presence of ground movements in post-mining area five decades after the end of mining activity and of varied nature, as well as substantiate the need for further investigation of this activity in the study area. These should include detailed analysis of the relation between groundwater level and benchmark heights and correlation of movements with the extent of shallow underground mining.

The research has been financed from the OPUS National Science Centre projects grant no. 2019/33/B/ST10/02975 and grant no 2021/43/B/ST10/02157.

How to cite: Walerysiak, N., Blachowski, J., Wajs, J., and Kujawa, P.: Analysis of ground movements in the post-mining area of the lignite mine “Babina” (W Poland), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14982, https://doi.org/10.5194/egusphere-egu24-14982, 2024.

X4.203
|
EGU24-17319
Marcin Lutyński and Konrad Kołodziej

Increase in the share of renewables in the energy mix of European Union gained interest in the large scale energy storage technologies. One of the promising technologies is the Compressed Air Energy Storage (CAES) where in conventional approach compressed air is stored in the cavern. An alternative solution that was developed at the Silesian University of Technology is to use a post-mining shaft for adiabatic compressed air energy storage (A-CAES). Availability of post-mining infrastructure and large number of shafts in European coal basins (over 178 shafts only in the Upper Silesia Coal Basin) shows a significant potential of this solution. In order to select a proper shaft with a considerable volume a screening tool was developed that uses multicriteria analysis for an initial selection of shafts that could be used for this technology. This tool takes into account shaft depth, diameter, type of shaft collar lining, water inflow rates and other criteria that are important for safety and energy capacity of the system. The presentation shows results of analysis of the shafts screening tool and case study for one of the shaft located in Poland.

How to cite: Lutyński, M. and Kołodziej, K.: Converting mine shaft into compressed air energy storage – shafts screening and assessment, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17319, https://doi.org/10.5194/egusphere-egu24-17319, 2024.

X4.204
|
EGU24-15004
|
ECS
Aleksandra Kaczmarek

Detection of temporary surface water is a critical aspect of monitoring the impact of mining on the environment and the impacts of underground gas storage (UGS) sites in particular. Recent years have been very dynamic for the energy sector, as increasing energy demand and the progression of global warming require constant improvements and changes. The general trend is to move away from conventional energy sources. However, green fuels require large storage volumes, which can be provided by geological storage. It can also be used to trap CO2 and thus contribute to the reduction of CO2 emission into the atmosphere.

Injection and withdrawal of gases in underground magazines affect the environment in a number of ways. Pressure changes and corresponding stress induce seismic activity, surface subsidence, and uplift. Gas leakage poses a risk to soil, water and air contamination. Therefore, it is necessary to treat UGS sites together with their surroundings in a holistic manner considering all potential impacts. The study UGS site is located in northern Poland. Natural gas is stored in salt caverns. The terrain to the north of the facility is of particular interest, as it is agricultural land with an old drainage system. It has not been maintained for years and the water reoccurs periodically. Low elevation and short distance to the sea favour flash flooding, which might be reinforced by UGS induced surface movements. The purpose of the test study is to detect surface water with a remote sensing based approach and establish the correlation between rainfall and surface water dynamics.

Satellite remote sensing provides a valuable means of continuous and large-scale monitoring of surface water dynamics. Spectral bands and indicators enable the discrimination of various types of land cover and their changes, including the appearance of flash water. The proposed methodology involves time-series analysis of open satellite data (Sentinel-2), spatial statistics, and comparative analysis of selected indicators and spectral bands used for water detection. Additionally, daily precipitation data from a local meteorological station were integrated into the analysis to evaluate the accuracy of surface water detection. Regression analysis has been done to analyse the relationship between the accumulation of water and rainfall, and therefore assess whether the indicators tested are suitable. 

The test analysis covers the period August 2015 - December 2023. The area of interest is cultivated. Crop fields, after harvest and before the vegetation season, are mostly bare soil, which can be mistakenly interpreted using basic plant moisture indices. Therefore, more combinations were tested and verified with rainfall data. By incorporating meteorological data, we aim to establish a more comprehensive understanding of the temporal variability in the presence of surface water near the gas storage site. The findings of this study contribute to the development of a complex monitoring system at a UGS site.

The research has been carried out under the project acronym CLEAR (grant no WPN/4/67/CLEAR/2022) financed from the Polish National Centre for Research and Development.

How to cite: Kaczmarek, A.: Flash Water Detection in Mining Areas Using Satellite Imagery and Meteorological Data , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15004, https://doi.org/10.5194/egusphere-egu24-15004, 2024.

X4.205
|
EGU24-19879
Thomas Grangeon, Tur Raphaël, Louis De Lary de Latour, Florian Masson, and Cerdan Olivier

Mining waste serves as a significant example illustrating the transport of contaminants in association with rainfall, runoff, and erosion. Due to past or ongoing metal extraction activities, mining waste deposits are widespread across numerous countries. Rainfall events affecting these areas can lead to environmental concerns due to both liquid and particulate transfers. Acid mine drainage has been extensively researched in this context, illustrating the transfers linked to the liquid phase. Furthermore, rock crushing and high metal concentrations in the waste create materials with minimal cohesion and little vegetation cover, making them highly susceptible to surface erosion. As a result, mine wastes may also be particularly prone to contaminant transport in the particulate phase, although such transfers have received comparatively less attention than liquid transfers. Assessments of surface erosion caused by rainfall and runoff are still lacking in literature, which limits our comprehension and ability to model these processes in these unique environments.

We propose estimating erosion rates on a 3.8-hectare post-mining site located in central France. Given the high erosion rates, we opted to combine two distinct methodologies based on elevation differences: i) erosion pins for simple and reliable but localized estimates of erosion rates, and ii) differences in Digital Elevation Models (DEMs). In this study, the DEM was obtained using a novel handheld laser scanner. Both methods yielded results within the same range, indicating substantial erosion rates and thereby highlighting the significance of particulate transport. Depending on the local circumstances (e.g., tailings characteristics, tailing-to-stream connectivity), future studies should consider both liquid and particulate transport from post-mining sites to develop relevant mitigation strategies.

How to cite: Grangeon, T., Raphaël, T., De Lary de Latour, L., Masson, F., and Olivier, C.: Erosion rates estimates on a post-mining site, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19879, https://doi.org/10.5194/egusphere-egu24-19879, 2024.