In this session, topics include:
• Exploration and extraction of critical raw materials as primary resources
• Sourcing of critical raw materials as byproducts (secondary resources) from common ores
• Revalorization of mine waste deposits (e.g., stockpiles & tailings) as secondary sources of critical raw materials
• Environmental aspects of extracting critical raw materials from primary resources
• Environmental and geotechnical innovations to address challenges related to mine waste facilities (revalorization and monitoring)
• Technological developments for sampling, characterization routines for ores and mine waste for enhanced resource and environmental assessment
• Innovative approaches for zero-waste mining and re-mining technologies, including geometallurgy and resource recovery
• The role of current regulations in shaping innovative solutions and promoting responsible extraction of critical materials from primary and secondary resources
• Multi-scale exploration of critical raw materials: innovative sensing techniques, automatization, and modeling of primary and secondary sources.
• Societal and economic challenges of opening new mines, and reactivating abandoned mines and waste facilities
• The role of AI and machine learning techniques across the mining life cycle
Orals: Wed, 30 Apr | Room -2.43
Platinum group metals (PGMs) are critical mineral resources for many countries, playing a critical role in energy transitions and the development of emerging strategic industries. Over 95% of global PGMs occur in co-associated forms. This study compiled data from 197 active PGM mines worldwide, representing 88.77% of global reserves. Using knowledge graph techniques, the study constructed a network of PGM co-associations, integrating these relationships into availability cost calculations to reduce prediction uncertainties. Data were processed using multiple imputation based on random forests and small-sample machine learning models optimized via grid search, and the availability was further evaluated using ensemble algorithms. The results reveal that PGM co-associations are mainly categorized into PGEs-Nickel-Copper±Cobalt±Silver and PGEs-Gold±Chromium, with XGBoost identified as the most effective algorithm for calculating availability costs, driven by factors such as total reserves, deposit type, milling capacity, and mining method. PGEs-Nickel-Copper±Cobalt±Silver associations exhibit higher availability costs and reserves compared to PGEs-Gold±Chromium. The supply trajectory of PGMs includes three phases and two critical risk points, with potential risks involving the depletion of 75% of cumulative reserves and exhaustion of low-cost mines in South Africa. Technological innovations and diversification in new energy vehicles can mitigate global PGM supply risks, but China’s demand-supply gap will persist, and only a high-recycling scenario can significantly enhance domestic supply security.
How to cite: Zhu, Y. and Xu, D.: Assessing the Global Availability of Platinum Group Metal Resources , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-223, https://doi.org/10.5194/egusphere-egu25-223, 2025.
The importance of critical raw materials (CRMs), such as rare earth elements (REEs), in high-tech industries and the growing demand for alternative sources have spurred interest in exploring unconventional deposits. Unconventional resources include a wide range of low-grade, high-tonnage ores. In the Baltic Paleobasin, two Lower-Ordovican formations bear significant CRM potential. Estonia's phosphorites, among Europe's most extensive phosphate rock reserves with a tonnage of 3Bt, are considered as REE prospects with extraction as a P by-product. The overlaying black shales, analogue of the Swedish Alum shale, are prospective for V, Mo and U. Assessing these poorly understood ores' economic potential and characteristics is essential to secure sustainable access to a wide range of elements and plan extraction procedures. Detailed investigations were conducted in the Toolse and Aseri deposits.
REE in Estonian phosphorites are carried by fragments of brachiopod shells, mineralised in carbonate fluorapatite (CFA). The shells are complex objects, apatite originating from the crystallisation of organic tissues and precipitation of secondary phosphate during burial, and later REE uptake during diagenesis, leading to diverse ΣREE signatures. Despite this variability, profiles present overall homogenous REE patterns, MREE-enriched up to 12-fold compared to PAAS, with positive Y and Ce anomalies indicative of a diagenetic overprint. Average ∑REE+Y concentration is 600±200ppm with 27% of apatite. In the lower part of the ore, ∑REE+Y reaches up to 1234 ppm with 60% of apatite. New LA-ICP-MS quantitative technique was applied to explore shell properties. The extent of diagenetic overprint and enrichment was found to vary locally, with specific REE grades on apatite edges. In Toolse, shells show less recrystallised textures - the average REE content is 1847±880ppm, with a maximum of 4150±1000ppm. In Aseri, LA-ICP-MS sorting first reveals a higher and more homogenous grade, 2440±450ppm, and a second alteration-driven enrichment stage in which the edges present a ΣREE up to 7020±3500ppm. Despite differences in enrichment level, REE distributions are similar. Main REEs are Ce(33%), Y(21%), La(12%), Nd(16%) and Dy(3%). The outlook coefficient was calculated to determine ore prospectivity (Seredin, 2010). It models the percentage of CR in total REE (REEdef) by the ratio of economical against excessive REE (Koutl). Both deposits fall in the 'promising for economic development' range. Therefore, the ratio of valuable REEs is relatively high.
Black shales were explored through two drill cores. They comprise thermally immature, organic-rich black, grey shales and siltstones. Study reveals maximum hyperenrichment in the basal part, with V content reaching up to 2349ppm and Mo up to 4500ppm, then gradually decreasing. The U content reaches up to 500ppm; however, elements present mismatching patterns, indicating a complex redox environment and specific enrichment mechanisms. Further experiments were conducted for particle fractionation, indicating that the main V carriers are the finest fractions (<2µm, illite-smectite), with V up to 4832ppm, while in organic-rich fractions, V content remained low (200ppm). Strong correlation between V-Cr-Al-Ti further confirms that hyperenrichment of V was largely controlled by clays and associated with dissolved OM.
How to cite: Graul, S., Ndiaye, M., Kallaste, T., Monchal, V., Joosu, L., Moilanen, M., and Hints, R.: CRM potential of EU sedimentary basins: Insights on Estonian phosphorites and black shales , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16358, https://doi.org/10.5194/egusphere-egu25-16358, 2025.
Critical minerals, particularly Rare Earth Elements (REE), are of growing global and national significance, especially in Australia. A multidisciplinary project aims to assess Australia’s potential for lower-grade REE resources, develop tailored processing technologies for CHRED and IAD deposits, and demonstrate their compatibility with existing REE separation techniques.
We aim to improve the deposit-scale understanding of REE mineral systems in Australia and deliver an integrated perspective of their formation and distribution. Key research areas include examining enrichment processes to show how REEs are mobilized from source materials and how their ratios evolve during deposit formation. Comprehensive ore characterization involves analyzing clay mineralogy, REE mineral distributions, compositions, and speciation. Additionally, the research investigates deposit heterogeneity by delineating REE concentrations across regolith profiles, unconsolidated sediments, and basement rocks, shedding light on REE cycling in natural systems.
By integrating these approaches, this work aims to unlock the potential of Australia’s CHRED and IAD deposits, supporting the sustainable and efficient development of critical mineral resources while addressing global demand for REEs.
How to cite: Reid, N., Thorne, R., Iglesias-Martinez, M., Lampinen, H., Davis, A., Fan, R., Valentim Berni, G., Teitler, Y., Miles, J., Spaggiari, C., and Pinchand, T.: Clay Hosted Rare Earth Element Deposits in Australia: A case study from Western Australia, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8004, https://doi.org/10.5194/egusphere-egu25-8004, 2025.
Critical elements, a vital component both for energy and technology, are receiving more attention globally. These elements could be anomalously concentrated in the coals, host rocks, and associated byproducts. In this context, the Alatepe coal occurrences in Mugla Basin (SW Anatolia, Turkiye), one of the most productive coal basins, can attract attention to the economic possibilities of V-U-Mo enrichments. The Alatepe outcrop coal samples were collected for analysis. The V, U, and Mo contents of studied coals are up to 175 μg/g, 69 μg/g, and 26 μg/g respectively. These samples are characterized by relatively low Al and Fe contents (avg. of 2.5 and 1.0 wt.%, respectively) and high S contents (avg. of 5.6 wt.%). The ash content of studied coals is up to 15 wt.% and petrographically characterized by a high huminite content. Based on the XRD analysis, the mineral composition of the studied samples is mainly of clay minerals, quartz, pyrite, gypsum, and mica suggesting that peatlands with a high detrital input, dominated by the quartz and clay mineral setting, may have been influenced by the sea in the Alatepe area. It can be stated that this situation increased coal ranking affecting the V content of studied coal samples and this higher maturation is probably attributed to more intensive post-depositional activities in these regions compared to the other coal fields in the Mugla Basin. Therefore, Alatepe coals can be classified as sub-bituminous C coal rank, while the main coal rank of the Mugla Basin is lignite. In addition, all of the redox indicators (such as V/Ni, V/(V+Ni), V/Cr, Ni/Co, Mo/Mn, and U/Th) suggest that reducing conditions provide a preservation condition for V-U-Mo. In these conditions, the form of V⁵⁺ reduced to its more reduced form, V³⁺, which then binds to organic material and surfaces like clays, leading to its accumulation. The U can be readily incorporated into organic and inorganic material as a form of insoluble U(IV). Moreover, Mo can form MoS₄²⁻, which readily precipitates and accumulates in sediments.
Keywords: V-U-Mo Enrichments, Critical Elements, Miocene Coals, Alatepe area, Mugla Basin (SW Anatolia of Turkiye)
How to cite: Sutcu, N. M. and Doner, Z.: Redox-Sensitive (V-U-Mo) Element Enrichments in Lower Miocene Coals from Alatepe area of Mugla Basin (SW Anatolia, Turkiye), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9197, https://doi.org/10.5194/egusphere-egu25-9197, 2025.
Seafloor Massive Sulphide (SMS) deposits have received global interest because of their high average grades of copper and zinc. However, the weathering processes of SMS deposits and the fate of metals during sulphide oxidation remain poorly understood, posing a potential ecological risk within the context of seafloor mining operations. Atacamite and Fe-oxyhydroxide (FeOOH) are key weathering products at SMS deposits, formed during the oxidation of sulphide minerals. These weathering products are hypothesized to trap base metals (i.e., copper and zinc), limiting their release into seawater. Here we study the processes that control the formation of sulphide weathering products and metal retention to provide new insights in metal release during seafloor mining and the valorisation of sulphide weathering products at these systems.
For this study, 31 samples of FeOOH with and without atacamite veins were obtained from the Semenov hydrothermal field on the Mid-Atlantic Ridge. Bulk geochemical analysis reveal copper grades of 2.40 wt.%, comparable to those in volcanogenic massive sulphide deposits, highlighting the potential of FeOOH and atacamite as a secondary resource at SMS deposits. Leaching experiments on nine samples of FeOOH with different amounts of atacamite show that the majority, i.e., 63.5% of copper within sulphide weathering products is found in atacamite veins hosted within FeOOH, while the FeOOH itself holds 32.5% copper. Additionally, our leaching experiments show that the occurrence of atacamite veins within FeOOH correlates with increased copper enrichment in FeOOH. While this may be due to copper adsorbing onto FeOOH during atacamite dissolution, this supports the natural capacity of FeOOH to adsorb copper in conditions where atacamite is unstable, akin to what could happen in natural SMS systems. For example, during chalcopyrite oxidation, copper is mobilised in acidic pore fluids, which may adsorb onto FeOOH at a low pH where atacamite is unable to precipitate. The mobilised fluid will then precipitate as atacamite veins when mixing with sufficient amounts of seawater.
To assess the ecological impact of sulphide weathering products, we conducted oxidative dissolution experiments on mixed sulphides under simulated seafloor conditions (~2.1°C, pH 8.2) over a two-week period in synthetic seawater. Results show that dissolved copper and zinc concentrations increased by approximately an order of magnitude above background synthetic seawater levels, i.e 35 vs 4.1 μg/L and for copper and 274 vs 33 μg/L for zinc. Extrapolation of constant oxidation rates from our experiments suggest that stockpiling 1,000 tonnes of sulphide ore at the seafloor could release up to 2,730 kg of zinc and 280 kg of copper annually. However, FeOOH precipitation occurring during our experiments, adsorbs dissolved metals from seawater, with a maximum of 23.1% of the total dissolved copper captured, thereby reducing metal release into seawater during the oxidative dissolution of sulphides.
Together, these findings demonstrate the potential of sulphide weathering products as secondary resources and as mitigators of ecological risk. The observation of atacamite could serve as an indicator for copper-rich FeOOH, while FeOOH precipitation provides a natural mechanism to adsorb metals, reducing their release during potential SMS mining operations.
How to cite: Bishop, C., Murton, B., Lichtschlag, A., Roberts, S., and Lesage, M.: Environmental and economic perspectives on Fe-oxyhydroxide and atacamite at seafloor massive sulphide deposits, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16655, https://doi.org/10.5194/egusphere-egu25-16655, 2025.
Our study presents a novel approach for predicting the distribution of subsurface minerals by utilizing multi-physics forward modeling and non-stationary Gaussian processes. By dividing a large exploration area into smaller segments, we can accurately estimate spatial models of physical properties. This method enhances traditional prediction techniques by incorporating geophysical and geological data, and non-stationary Gaussian processes, resulting in more precise and reliable subsurface models. Simulation is performed by using a highly parallelizable flood-fill sampling algorithm that enables our Gaussian process method to scale to address large spatial domains. Our approach has significant implications for the efficient and sustainable exploration of critical mineral resources, aiding in the global transition to renewable energy.
How to cite: Daza, J. P., Caers, J., Li, P., Yin, D. Z., and Eddy, D.: Multi-physics Inversion by Gradual Deformation of Non-stationary Gaussian Processes, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14741, https://doi.org/10.5194/egusphere-egu25-14741, 2025.
Overview/Background
The global mining sector faces unprecedented challenges as it navigates intensifying geopolitical tensions, opaque markets, mounting environmental concerns, and increasingly complex social license issues. This research presents a comprehensive scenario analysis examining potential futures for the mining industry through 2050, developed through a rigorous methodology combining expert knowledge with strategic foresight methods.
Methods
The study employed a structured scenario technique leveraging the PESTEL framework and incorporating input from industry experts across Europe and the United States. Through workshops conducted in 2023 and 2024, researchers identified 20 main factors driving the mining industry's future. These factors were analysed using Cross-Impact Balances methodology and the ScenarioWizard Tool, initially generating nine scenarios that were subsequently consolidated into four distinct futures.
Results
The analysis yielded four contrasting scenarios: (1) "The Advancement Wave", characterised by technology-driven progress but widening inequality; (2) "Divided Dominions", depicting fragmented trade blocs and market distortion; (3) "Downward Spiral", showing widespread resource nationalism and environmental degradation; and (4) "The Great Transition", presenting unprecedented international cooperation following a global catastrophe. Each scenario explores interconnected dimensions including international cooperation, economic conditions, social dynamics, environmental aspects, and technological development within the mineral raw materials sector.
Conclusions
The research identified five fundamental differentiators determining the extractive industry’s trajectory: technological innovation adoption, societal acceptance of mining operations, stability of policy frameworks, management of demand volatility, and degree of international cooperation. The findings emphasise that while the industry's future remains malleable, success requires sustained political commitment and policy stability across electoral cycles, alongside careful balance between domestic security and international cooperation, environmental protection and economic development, and local impacts versus global benefits.
Policy Implications
Evidence from all scenarios demonstrates that geopolitics is the primary factor shaping the future of the mining sector. Moving towards more positive outcomes requires decisive actions: maintaining strong public support for R&D, improving societal acceptance through reformed permitting processes, creating mechanisms to minimise market cyclicity, enhancing multilateral cooperation, and developing long-term strategic planning beyond electoral cycles. These findings provide valuable insights for policy-makers in shaping resilient strategies to secure the supply of mineral raw materials.
How to cite: Correia, V., Keane, C., Komac, M., Falck, E., Oysul, Z., and Schuele, S.: Future Mining Scenarios: A Forward-Looking Exploration of the Mining Industry through 2050, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17612, https://doi.org/10.5194/egusphere-egu25-17612, 2025.
Critical metal extraction from laterite ores using reductive dissolution and Fe(II) catalysed recrystallisation
Maximilian Mann1, Andrew J Frierdich1, Zhen Wang1 and Jessica Hamilton2
1School of Earth, Atmosphere & Environment, Monash University, 9 Rainforest Walk, Clayton, Victoria, 3168, Australia
2Australian Synchrotron (ANSTO), 800 Blackburn Rd, Clayton, Victoria, 3168, Australia
Critical metals such as nickel (Ni) and cobalt (Co), are essential for modern green technologies (e.g., solar panels, windmill turbines and batteries)[1, 2]. The majority of the world’s Ni reserves are associated with iron (oxyhydr)oxides or laterites [3], while Co is mostly a by-product of Ni and Cu mining [4]. To produce Co metal, the three main deposit types are nickel sulphide ores, copper sulphide ores and nickel laterites [4]. This work examines the extraction of Co and Ni from various mining ores using Fe(II)-catalysed recrystallisation. Compared to conventional Ni extraction techniques that often involve high-pressure acid leaching, Fe(II)-catalysed recrystallisation has been shown to enhance the release of Ni from goethite and hematite under ambient and circumneutral pH, thus offering an environmentally benign strategy for Ni extraction. Although high Co release was observed, the Ni release was lower as expected. Interestingly, along with the high Co release, a high Mn release was also observed. As Co is often associated with manganese oxides [4], is seems that the Fe(II) used for the recrystallisation lead to a reductive dissolution of these manganese oxides resulting in Co release. This led to the conclusion that the Fe(II) is consumed during a reductive dissolution of cobalt rich manganese oxides. Hence, further experiments are underway to determine if more Co and Ni release can be archived by the addition of more Fe (II). Exploring these alternative Ni and Co extraction and recovery pathways can help reduce the environmental impact of mining and supply the resources needed for green technologies.
1. Dupuis, C. and G. Beaudoin, Discriminant diagrams for iron oxide trace element fingerprinting of mineral deposit types. Mineralium Deposita, 2011. 46(4): p. 319-335.
2. P.M.Y.V.Dathu, K. and R. Hariharan, Design of wind turbine blade material for higher efficiency. Materials Today: Proceedings, 2020. 33: p. 565-569.
3. Mudd, G.M. and S.M. Jowitt, The New Century for Nickel Resources, Reserves, and Mining: Reassessing the Sustainability of the Devil’s Metal. Economic Geology, 2022. 117(8): p. 1961-1983.
4. Dehaine, Q., et al., Geometallurgy of cobalt ores: A review. Minerals Engineering, 2021. 160: p. 106656.
How to cite: Mann, M., Frierdich, A., Wang, Z., and Hamilton, J.: Critical metal extraction from laterite ores using reductive dissolution and Fe(II) catalysed recrystallisation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7467, https://doi.org/10.5194/egusphere-egu25-7467, 2025.
Although North Macedonia covers only 0.7 % of the Earth's surface, it contains 3 % of the world's mineral deposits (Jovanovski et al. 2018). Both historical and recent mining operations in the country have left extensive waste deposits, particularly from operations focused on the exploration of antimony (Sb), arsenic (As), chromium (Cr), copper (Cu), lead (Pb), zinc (Zn) and thallium (Tl). Over the past six years, we have intensively studied the mineralogy and geochemistry of two abandoned deposits, Lojane, a former Sb-As-Cr mine, and Allchar, a former Tl-As-Sb-Au mine (Đorđević et al. 2019, 2021; Kolitsch et al. 2018; Serafimovski et al. 2023; Vaňek et al. 2024). Historical mining practices, characterised by inadequate waste management, have resulted in huge accumulations of mining and processing wastes containing both economically valuable (Sb, As, Ba, Ni, Co, Pb, Cu, Zn) and environmentally hazardous elements (Cd, Cr, Hg, Tl). These sites now present a double challenge: environmental pollution and untapped resource potential.
The prediction of the environmental impact or strategic potential of these wastes is based on their mineralogical composition. Therefore, the precise characterisation of the host minerals and the possibility of their sequestration by secondary minerals is crucial for understanding such potential. At both the Lojane and Allchar deposits, we investigated the retention of As, Ba, Cr, Ni, Sb and Tl within secondary minerals in different mine waste environments. Minerals like scorodite, roméite-group antimonates, and pharmacosiderite-group minerals have been identified as significant reservoirs for arsenic (As), antimony (Sb), and thallium (Tl). These minerals help immobilize these elements, reducing their immediate environmental mobility. The high concentrations of valuable elements (e.g., Sb, Tl, and Ni) in both primary and secondary minerals from the various waste environments (waste rock, tailings, technosols) present opportunities for resource recovery. Effective leaching and extraction technologies could turn these environmental burdens into economic assets.
By identifying specific mineral reservoirs and understanding their mobilisation potential, our research contributes to the development of contamination risk management strategies for polluted sites, linking mineralogical processes to practical environmental remediation requirements. Furthermore, by turning these environmental burdens into assets, Northern Macedonia has the potential to set a regional example for the long-term management of mine waste.
Financial support of the Austrian Science Fund (FWF) [P 36828-N] to T. Đorđević is gratefully acknowledged.
References:
Đorđević, T. et al. (2019): Can. Mineral., 57, 10–21.
Đorđević, T. et al. (2021): J. Appl. Geochem., 135.
Kolitsch, U. et al. (2018): Geologica Macedonica, 32, 95–117.
Jovanovski, G. et al. (2018): Allchar, a world natural heritage, Macedonian Academy of Arts and Sci., 238 pp
Serafimovski, T. et al. (2023): Geol. Ore Deposits, 65, 315-331.
Vaňek, A. et al. (2024): Environ. Pollution, 357, 124413–124421.
How to cite: Đorđević, T., Tasev, G., Serafimovski, T., Boev, I., and Boev, B.: Balancing between environmental pollution and unutilized resource potential: mine wastes of North Macedonia, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10258, https://doi.org/10.5194/egusphere-egu25-10258, 2025.
In the energy transition era, the supply risk of critical raw materials (CRMs) must be addressed with strategic efficiency and expertise to address the pressing challenges of climate change, increasing resource demands and to support the objectives of the European Green Deal. Strengthening local production and promoting the sustainable management of CRMs is essential to reduce reliance on imports and ensure a resilient supply chain.
As the emphasis on sustainable resource practices increases, the demand for skilled professionals to oversee the responsible and secure extraction of these materials is increasing. However, a major challenge in Europe is the shortage of qualified professionals in the mining and mineral resources sector. Universities have been identified as playing a pivotal role in addressing the deficit in professional training by adopting innovative learning and teaching methods. The integration of advanced digitization technologies into educational frameworks is a key aspect of this, ensuring that students are equipped with the knowledge and skills necessary to support the sustainable development of the mining industry.
The IMMERSE (Immersive Virtual Tours on Critical Minerals for Clean Energy Transition) project constitutes an innovative educational initiative focused on the development of Virtual Excursions (VEs) to enhance learning in the CRMs sector. This collaborative project brings together leading universities from Europe and Australia to address the skills gap in mining and geoscience training by employing cutting-edge teaching approaches that prioritize sustainability.
The VEs serve as cutting-edge educational tools that allow students to safely engage with scenarios that are otherwise difficult to access or present safety concerns in real-world environments. By replicating real mining environments through immersive online experiences, VEs allow students to explore ongoing research and industry practices without the constraints of geography. These virtual platforms encourage the exploration of sustainable practices and innovative solutions to today's mining challenges, aligning educational goals with industry needs.
The realisation of the IMMERSE project has been made possible by funding from the ERASMUS+ grant programme of the European Union (grant number: 2023-1-DE01-KA220-HED-000165332). We are deeply grateful for their invaluable support, which has enabled us to undertake this important endeavour. Their commitment to promoting educational initiatives and intercultural exchange has been instrumental in shaping the trajectory of our project and empowering us to make meaningful contributions to our field.
How to cite: Machairas, E., Varouchakis, E., Lottermoser, B. G., Leilabadi, S. H., Roach, M., Barrionuevo, F. G., Macias, M. T., and Nieto, J. M.: Innovative Training in Critical Raw Materials: The IMMERSE Project's Role in Advancing Education for the Clean Energy Transition, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15577, https://doi.org/10.5194/egusphere-egu25-15577, 2025.
Posters on site: Thu, 1 May, 10:45–12:30 | Hall X4
In this century, the intensity of road traffic has reached unprecedented levels, with an extraordinary number of vehicles circulating on the streets. Another notable aspect is the rapid rate of vehicle proliferation, driving the need for innovative approaches to enhance asphalt mixtures that can sustain this challenge. This paper aims to explore transformations brought by the rationalization and utilization of waste materials while presenting examples of their integration in reuse processes. Specifically, it discusses how industrial waste such as metallurgical slags, coal ash from power plants, and residual rubber can act as viable substitutes for widely used natural aggregates in asphalt mixtures.
In practice, these materials exhibit two key attributes for such applications.
The foremost quality is their comparable properties to conventional aggregates. Research shows that waste materials like power plant slags and ashes possess characteristics similar to those of aggregates typically used in asphalt production, with some even providing enhanced performance benefits. The second attribute is the ample availability of these materials, stored in quantities often exceeding demand. For example, substantial amounts of residual rubber can partially replace bitumen in asphalt mixtures, leading to considerable cost reductions.
Additionally, the fact that residual industrial materials are otherwise regarded as waste and contribute to pollution reinforces the value of replacing natural aggregates with artificial alternatives. Each of these waste materials has been subjected to rigorous laboratory testing to evaluate the properties they impart when substituting asphalt components. Furthermore, tests on reclaimed asphalt (recycled asphalt) demonstrate the potential to reuse older materials, thereby reducing reliance on natural resources and lowering production expenses.
The judicious use of industrial waste offers significant environmental advantages. The massive accumulation of slag and ash, which poses disposal challenges, can be repurposed effectively, alleviating environmental degradation. This research highlights the importance of incorporating waste materials into asphalt production to achieve sustainable development, optimize resource use, and protect natural ecosystems.
Key words: Aggregates, Pollution, Reuse, Waste
How to cite: Bogdan, B.: Reduction of Raw Material Consumption in the Manufacture of Asphalt Mixtures Using Modern Technologies, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6143, https://doi.org/10.5194/egusphere-egu25-6143, 2025.
Silica is the key constituent in production of glass, responsible for its structure, and it typically originates from quartz sand. Quartz-rich sand, commonly used as a primary raw material in glass production, may contain trace amounts of heavy minerals. The presence of these heavy minerals may compromise the quality of raw material and decrease the purity factor. In the glass industry it is believed that this trace amount of heavy mineral content may also act as contaminant and impurity which may affect the coloration of transparent glass. In this study, raw material samples (total five) of quartz rich sand are analyzed for studying proportion of heavy mineral content which contributed as impurity. To determine the heavy mineral content a gravimetric separation technique is used (Andò, 2020). By using this technique, from the bulk samples, approximately 30g of sediment was used for wet sieving to obtain a grain size window of 15-500µm, which is considered the most appropriate to identify the suite and amount of heavy minerals. The sieved fraction is mixed with a non-toxic heavy-liquid sodium polytungstate, with a density of 2.90g/cm 3 , to separate the heavy and light minerals using a centrifuge. A representative aliquot of HM separated is mounted on a slide for microscopic analysis. The investigation of grain mount is carried out by using point counting technique to measure quantitatively the proportion and percentage of different single heavy minerals. The heavy mineral fraction also contains the presence of opaque mineral impurities, which are also considered, due to their contribution as the major contaminants. The results indicate that in all studied samples, overall, the presence of heavy mineral percentage ranges from 0.02% to 0.35%. The most frequently occurring heavy minerals include zircon, rutile, apatite, tourmaline, andalusite and kyanite across all the five samples. The presence of these heavy minerals along with opaque mineral, may contribute as an impurity in the transparent glass, potentially impacting the production process. Furthermore, during the melting process, new minerals can crystallize and incorporated as defects within the final glass product. The identification of these defects (mineral inclusion) in final glass product is also being investigated using optical microscopy and Raman spectroscopy. This approach aims to enable glass manufacturers to identify mineral impurities more quickly and conveniently.
How to cite: Mehboob, S., Ando, S., and De Lorenzi, V.: Heavy Minerals As a Contaminant From The Quartz Rich Sand Used As Raw Material In Glass Industry, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7113, https://doi.org/10.5194/egusphere-egu25-7113, 2025.
The ceramic tile industry has resumed its growth around the world post-Covid 19, and Brazil ranks third among the largest producers and consumers. Among the products manufactured in Brazil, two stand out: porcelain tiles, produced by the traditional wet process, and semi-porous slabs, produced by the dry process, developed in Brazil. Porcelain tiles, the subject of the work presented here, are produced in two main Brazilian centers, Criciuma and Santa Gertrudes, located in the south and southeast of Brazil. Current production is expected to reach 200 million square meters in 2023. Porcelain tiles are made from a mixture of raw materials, particularly plastic and superplastic clays, which account for 30 to 40% of the total, and feldspars, which make up around 25 to 40%. Given the growing need for supplies for the manufacture of porcelain tiles, especially with regard to feldspars and plastic clays, this research focused on exploring and geologically, geochemically and technologically characterizing new sources of these traditional raw materials, as well as special fluxes and alternative sources of raw materials in different geological environments, especially in the southeast and northeast regions of Brazil. The methodology adopted involved carrying out geological mapping in pre-selected regions, which included the description of lithofacies, lithogeochemical characterization using techniques such as X-ray diffraction, X-ray fluorescence and the analysis of thin sheets, as well as the evaluation of ceramic properties, including water absorption, apparent density and mechanical strength, among other parameters. For some samples with innovative potential, additional analyses were carried out. Preliminary results indicated that some samples showed promise as raw materials for the manufacture of porcelain tiles, especially the alkaline fusion raw materials and plastic clays. Among the alkaline source rocks, nepheline syenite and anorthosite stood out, with an estimated composition of 60 to 90% feldspars, as well as 20% nepheline and 15% cancrinite, which showed high sum values of fusing elements (Na₂O + K₂O), reaching more than 18%. Another focus of analysis was diopside, which showed mineralogy composed of diopside, quartz and feldspar, with high levels of (CaO + MgO), which favored fusibility during firing, improving mechanical strength and decreasing water absorption, and reducing energy costs. With regard to plastic clays, some Quaternary and Permian deposits, consisting mainly of quartz minerals, feldspar (microcline) and the clay minerals kaolinite, illite and smectite, have shown remarkable ceramic performance, with high plasticity, high dry mechanical strength and light colors after firing. The initial results suggest that it is viable for use in coatings, but further research could expand its potential, including the search for new products through technological innovations. The authors gratefully acknowledge the financial support of FAPESP - Fundação de Amparo à Pesquisa do Estado de São Paulo, Process nº 2023/01939-0, project, Prospection and characterization of brazilian raw materials for the production of porcelain tiles.
How to cite: Christofoletti, S. R., Marciano Motta, J. F., Dondi, M., Zanardo, A., Tomazini Conceição, F., Beltran Navarro, G. R., Cabral Júnior, M., and Gomes Melchiades, F.: Characterization of brazilian plastic and flux raw materials for application and innovation in the ceramic coating industry., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7184, https://doi.org/10.5194/egusphere-egu25-7184, 2025.
The global transition to clean energy necessitates a substantial increase in the production of energy transition minerals and metals (ETMs). As a major producer of ETMs such as nickel and copper, the Philippines is well-positioned to leverage its mineral resources for economic growth. Key mechanisms, such as the Social Development and Management Plan and the Extractive Industries Transparency Initiative, have advanced community benefits and transparency in the large-scale mining sector. However, as one of the most biodiverse countries and highly vulnerable to climate change, the Philippines requires stronger policy, governance, and stakeholder collaboration that aligns mineral extraction with the UN Sustainable Development and climate action goals. This work presents three complementary approaches to help achieve sustainable mining in the Philippines. First, a river catchment-based management framework is proposed, incorporating catchment-specific environmental guidelines tailored to the country's geological diversity. This framework is essential for assessing the health and functionality of rivers, identifying contamination sources, understanding catchment connectivity, and planning targeted management, remediation, and prevention strategies. Second, we advocate for formalizing and regulating artisanal and small-scale mining (ASM) through innovative policy interventions, such as institutionalized synergies between ASM and large-scale mining, fostering socio-economic equity and environmental accountability. Lastly, the guardian watersheds concept is introduced, establishing protected zones to naturally attenuate contaminants from mining-impacted areas, and complementing existing environmental safeguards. Collectively, these measures set a basis for global best practices while addressing mining-related socio-ecological challenges in the Philippines.
How to cite: Domingo, J. P., Contreras, A., Tortajada, C., Faustino-Eslava, D., Hudson-Edwards, K., Williams, R., and Byrne, P.: Sustainable mining management frameworks in the Philippines, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8760, https://doi.org/10.5194/egusphere-egu25-8760, 2025.
The grey water footprint (GWF) concept quantifies the volume of water required to dilute pollutants from industrial processes, such as mining, to safe levels in downstream water systems. In this study, we apply the GWF concept to tailing ponds, where pollutants leach into surrounding environments. The GWF represents the water needed to reduce the concentration of pollutants to acceptable levels, considering both pollutant release rates and natural background concentrations. While the GWF concept is promising for managing the environmental impact of mining, its application to tailing ponds is challenged by data scarcity and the complexity of these pollutants, including accumulation, release dynamics and reaction with the environment. To address this, we propose a model that balances site-specific accuracy with cross-site transferrability, ensuring it can be applied to a range of tailing pond settings with limited data. By focusing on key processes like seepage and adsorption, the model allows for practical estimation of pollutant fluxes and supports more effective water management strategies in data-scarce contexts, providing a valuable tool for assessing the environmental risks of mining operations. The approach will be demonstrated on a representative mining site, showcasing its practical utility in real-world mining scenarios.
How to cite: Muller, M. F., Jimenez-Martinez, J., El-Ajou, N., Faure, J., and Pool, S.: Estimating the Grey Water Footprint of Tailing Ponds: A Transferable Reactive Transport Model , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9340, https://doi.org/10.5194/egusphere-egu25-9340, 2025.
For the world to transition from fossil fuels to renewable energy, a significant amount of raw materials is required. For example, in order to build the electricity grid needed for the move to ‘green’ electricity, we need to mine the same amount of copper in the next 30-40 years as in the entire history of mankind combined (Cathles and Simon, 2024). The difficulty of finding large geogene deposits of copper and other critical metals requires us to identify alternative sources of these critical and strategic metals.
We note that for much of human history, the extraction of metals from natural ores was significantly less efficient than it is today. Therefore, the mine waste of historic districts can still contain considerable quantities of raw materials. This is particularly true for the historic Cu-Au-As mining districts of the Eastern Alps. Recoveries for the produced metals (such as copper and gold) were between 50-66%, with the rest ending up as mine waste, largely in the form of sulfide minerals (Paar et al., 2006). These sulfide rich mine wastes can also be a source of critical metals that tend to associate with Au and Cu (i.e. As, W, Bi, In, Te; Gopon et al., 2019; Goebel, 2024; Hiller, 2024), as well as groundwater contamination.
By combining whole rock geochemistry, geophysics, and advanced micro- to atomic-scale characterization techniques we have produced estimates of the raw material potential of the 4000+ Cu-Au-As mine dumps found throughout the Eastern Alps. We will show examples from historic Cu-Au-As districts from the Hohe Tauern to the Fischbacher Alpen, and discuss which raw materials are present, in what form they are present, and how sulfide minerals are able to host such a diversity of important metals. The environmental impact of these sulfide rich mine wastes will also be discussed, as well as the possibility of remediating these former mine sites by re-mining the mine dumps.
The mining and metallurgical techniques required to process weathered, low grade, and arsenic rich ore pose a significant challenge. To this end we have started a combined geological, geophysical, environmental, metallurgical, and mining engineering study focused on a particularly well-suited Cu-Au mining district in the vicinity of Spielberg, Austria (Flatschach, Styria). This work is part of the SCIMIN project, which is looking at four mining waste sites across Europe (Spain, Bosnia, Sweden, Austria) and is funded by the European Union as part of the Horizon Europe Research and Innovation Programme (No. 101177746).
References:
Cathles, L., Simon, A., 2024, Copper Mining and Vehicle Electrification: International Energy Forum, 26p.
Goebel, E., 2024, Sulfide Geochemistry of the Hohen Tauern Historic Gold Districts (Austria): Montanuniversität Leoben.
Gopon, P., Douglas, J.O., et al., 2019, A Nanoscale Investigation of Carlin-Type Gold Deposits: An Atom-Scale Elemental and Isotopic Perspective: Economic Geology, v.114, p.1123–1133, doi:10.5382/econgeo.4676.
Hiller, J., 2024, A green future from a contentious past: Gold and critical metals in a historic arsenic mining district Straßegg (Styria): Montanuniversität Leoben.
Paar, W.H., et al., 2006, Das Buch von Tauerngold: Salzburg, AT, Anton Pustet, 570p.
How to cite: Dunkel, F., Bertrandsson Erlandsson, V., Douglas, J. O., Hanke, G., Jameshourani, S., Felfer, P., Wagner, S., Varelija, M., Angerer, T., Hartlieb, P., Antrekowitsch, J., and Gopon, P.: Precious and critical metal potential of historic Cu-Au-As mine waste in the Eastern Alps, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9986, https://doi.org/10.5194/egusphere-egu25-9986, 2025.
Mining operations produce vast amounts of waste, posing critical geotechnical, environmental, and social risks. The EU Horizon-funded Multiscale Observation Services for Mining-Related Deposits (MOSMIN) project addresses these challenges by developing integrated Earth Observation (EO)-based services that combine satellite, uncrewed aerial vehicle (UAV), and in-situ data. These services aim to deliver innovative multi-scale, multi-source solutions for enhanced environmental and geotechnical monitoring as well as valorisation, aligning with environmental, social, and governance (ESG) goals in the raw materials industry. MOSMIN’s case studies across diverse mining sites demonstrate the real-world application and benefits of these services.
We apply this integrated framework at the Roșia Poieni open-pit porphyry copper mine in Romania to monitor its environmental impact and to support the development of effective remediation strategies. We use long-term satellite archives for temporal analysis of large-scale impacts, augmented by high-resolution UAV and in-situ data for localized insights and validation. Ground-truthed hyperspectral satellite (e.g. EnMAP) data allow us to map the mineral composition of waste rocks, identifying potential acid-generating and buffering materials. Multispectral Sentinel-2 and Landsat data enable monitoring of vegetation health and water quality over time, offering insights into the downstream effects of acid mine drainage (AMD). We then conduct supervised mapping of hydrogeochemical properties and AMD-associated minerals in sediments based on UAV hyperspectral data in areas of interest identified in the satellite data. Sentinel-1 InSAR and UAV-based topographic data provide displacement susceptibility maps.
Our results highlight the substantial environmental impacts of mining at Roșia Poieni. The waste rock dumps are predominantly characterized by argillic alteration, interspersed with potassic and phyllic alteration zones enriched in sulfides, which are potential sources of AMD. Secondary iron minerals spectrally identified within the dumps and downstream sediments provide clear evidence of AMD, as do elevated AMWI (Acid Mine Water Index) values in the water runoff, which show strong correlations with measured dissolved iron concentrations and pH levels. A 30-year Fourier-based harmonic analysis of vegetation indices reveals a progressive decline in vegetation health around the tailings pond and waste rock dumps, largely driven by mine expansion. In contrast, areas northwest of the open pit and downstream of the tailings dam show net vegetation recovery, suggesting effective reclamation measures. InSAR-derived displacement data highlight accumulated ground movements of up to 200 mm per year in parts of the northern waste rock dump, raising concerns about geotechnical stability.
This case study highlights the value of integrated EO-based monitoring for understanding mining’s environmental impacts. The insights gained enable informed decision-making, support targeted remediation of existing issues, and facilitate mitigation measures to prevent future harm, through collaboration with local communities, governments, and the mine operator.
How to cite: Kirsch, M., Lorenz, S., Gloaguen, R., Baciu, C., Kerekes, A.-H., Deaconu, L.-T., Djaddaoui, F., Monserrat, O., and Pavel, N.: Satellite-based, integrated environmental monitoring of mine sites: an example from the Roşia Poieni copper mine, Romania, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13273, https://doi.org/10.5194/egusphere-egu25-13273, 2025.
The EU-Horizon-funded project Multiscale Observation Services for Mining-related Deposits (MOSMIN) aims to develop comprehensive services for the geotechnical and environmental monitoring of mine waste to improve the safety, efficiency, and transparency of mining operations. Monitoring moisture and water ponding in tailings storage facilities (TSF) is important for safeguarding the geotechnical stability of these structures and optimising operational efficiency, including discharge planning, water reuse, and dust control.
Satellite-based moisture monitoring of tailings is a cost-effective alternative to traditionally employed in situ sensors, as it provides large-scale and long-term coverage. Spectral indices from multispectral satellite data have been used successfully as moisture proxies in TSF, and as a basis to track size and bathymetry of decant ponds. While this is a viable methodology in arid regions, synthetic aperture radar (SAR), an active technique employing microwaves that can penetrate clouds, provides an alternative in more challenging atmospheric conditions. In this contribution, we explore the possibilities of using Sentinel-1 SAR data for moisture estimation within TSF, focusing on the Talabre TSF in Chile, one of MOSMIN's pilot sites, which, due to its desert climate provides the opportunity for cross-validation with optical soil moisture proxies. A qualitative estimate of relative soil moisture, showing strong agreement with optical-derived moisture estimates, can be obtained by normalising backscatter values using a time series to establish minimum and maximum bounds. However, in contrast to natural soils, which tend to have consistent surface roughness characteristics over time, tailings at Talabre exhibit smooth surfaces when wet and are prone to rapid desiccation, creating rougher surfaces as they dry, which leads to a negative relationship between SAR backscatter and moisture.
Salts forming on tailings are another complicating factor, acting as barriers to evaporation and obscuring the moisture-related backscatter behaviour outlined above. In SAR backscatter time-series, we observe that certain areas show a slower rate of increase in backscatter during drying periods than others. The spectral signatures extracted from Enmap hyperspectral satellite data suggest that these regions correspond to tailings impacted by salt formation, providing an effective means to identify salt-affected areas (and excluding them from moisture estimation).
For water body delimitation, thresholding the backscatter intensity based on the premise that water acts as a specular reflector, works well in most situations. For windy areas, we present a new method to delineate water bodies which uses paired Sentinel-1 images from different incidence angles, acquired from different look directions, to detect deviations in backscatter caused by wind-induced Bragg scattering.
These findings underscore the potential of integrating earth observation data to provide reliable and versatile moisture monitoring services in TSFs for proactive mine management and sustainable resource development.
How to cite: Quigley, C., Gao, Q., Kirsch, M., Monserrat, O., and Gloaguen, R.: Leveraging multi-sensor remote sensing for monitoring moisture in tailings storage facilities, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13461, https://doi.org/10.5194/egusphere-egu25-13461, 2025.
Rare earth elements (REEs), as a group, make up the raw materials scored with the highest supply risk and economic importance out of the numerous critical raw materials listed by the European Union. This is due to the very limited source of REEs and its key-role in a wide range of high-tech applications (e.g., electro-magnets and high storage capacity batteries), many of them related to the green energy infrastructure and the defense industry. As is with most of the metals needed for an energy transition, demand predictions show high increases for REEs – up to seven times current production by just 2040 (European Commission, 2023). To achieve these goals and predictions, we need to re-envision what mining is, and what is being mined.
Kiruna-type iron-oxide-apatite (IOA) deposits in the Bergslagen region (central Sweden) were mined for centuries, with the largest deposit being the Grängesberg ore field – mined from the 1500s until 1989. The Grängesberg mining operation is since 1989 inactive and all that is left after the ~150 million tons of ore production (Allen et al., 2013), besides the open pits, are large piles of gangue waste material (e.g., 3.46 dry Mt Indicated Mineral Resources at the Jan-Matts tailings dam; Lindholm, 2021). At the time of production, the Grängesberg ore was solely processed for iron bearing minerals. However, as is apparent in the deposit type name (IOA), apatite is present in significant concentrations in the ore. It at the time it was viewed as waste rock and deposited as stamp sands in large waste piles.
Apatite, along with monazite that also occurs in the Grängesberg ore (e.g., Jonsson et al., 2016), are both well-known hosts of REEs. The presence of these minerals in the mine waste poses a possible ‘new’ source for REE in Europe. This study aims to constrain the mineralogical occurrence, distribution, and type of REEs, and other critical metals, in the mine waste from the Grängesberg deposit to evaluate the potential of extracting these metals.
Acknowledgements
This project is funded by the European Union. Views and opinions expressed are however those of the authors only and do not necessarily reflect those of the European Union. Neither the European Union nor the granting authority can be held responsible for them. This project has received funding from the European Union's Horizon Europe research and innovation programme under grant agreement No 101177746.
Allen, R., Jansson, N., & Ripa, M. (2013). SWE4 Bergslagen: Geology of the volcanic- and limestone-hosted base metal and iron oxide deposits (excursion guide).
European Commission. (2023). Study on the Critical Raw Materials for the EU 2023 – Final Report (European Commission, Ed.). https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en
Jonsson, E., Harlov, D. E., MaJka, J., Högdahl, K., & Persson-Nilsson, K. (2016). Fluorapatite-monazite-allanite relations in the Grängesberg apatite-iron oxide ore district, Bergslagen, Sweden. American Mineralogist, 101(8), 1769–1782. https://doi.org/10.2138/am-2016-5655
Lindholm, T. (2022). Jan-Matts tailings dam, Grängesberg - Updated Mineral Resource Estimate. GeoVista AB.
How to cite: Bertrandsson Erlandsson, V., Bhadani, K., Asbjörnsson, G., Varelija, M., Gopon, P., and Hellingwerf, R.: RE(E)-mining what’s left behind: unravelling the mineralogy, distribution, and mining potential of REEs in Grängesberg IOA mine wastes (Bergslagen, Sweden), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15875, https://doi.org/10.5194/egusphere-egu25-15875, 2025.
Global trends indicate that the demand for many Critical Raw Materials (CRMs) and Strategic Raw Materials (SRMs) is rising and is expected to increase dramatically in the near future. These minerals are essential for key industries, including automotive and electronics, and serve as crucial enablers of the green energy transition, playing a vital role in achieving net-zero climate targets. To meet this increasing demand, it is crucial to enhance the characterization and modelling of these materials to better understand their quantity and distribution in both primary and secondary resources, such as mine waste. Sensor technologies could provide an effective solution for raw material characterization, supporting this effort. In this work, a data-driven methodology employing machine learning techniques is proposed. It utilizes laser-induced breakdown spectroscopy (LIBS) and visible-near infrared/short-wave infrared (VNIR/SWIR) spectral data to achieve more accurate characterization of lithium, a critical SRM, in lithium-bearing pegmatite deposits. The methodology commences with data exploration and pre-processing, followed by an evaluation of the techniques' effectiveness in element and mineral identification. This is followed by data modelling and validation. The collected spectral data were used to develop classification models, using Support Vector Classification (SVC) and Linear Discriminant Analysis (LDA), as well as predictive models for the prediction of Lithium concentration using Partial Least Squares Regression (PLSR) and Support Vector Regression (SVR). The results show that using these techniques coupled with machine learning significantly enhances the compositional analysis of lithium ore. The findings suggest that this approach can improve material characterization, enable effective process control, and help define the requirements for mineral processing. As a result, it could potentially increase the efficiency of mining and re-mining operations.
How to cite: Desta, F. and Buxton, M.: Multi-Sensor Approach for Enhanced Characterization of Lithium Ore, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20276, https://doi.org/10.5194/egusphere-egu25-20276, 2025.
Posters virtual: Thu, 1 May, 14:00–15:45 | vPoster spot 4
EGU25-2493 | ECS | Posters virtual | VPS17
Integrating Neutron Activation Analysis and Multi-Index Assessments to Evaluate Rare Earth Elements in Sudanese Gold Mining AreasThu, 01 May, 14:00–15:45 (CEST) | vP4.13
Rare earth elements (REE) have become indispensable in a wide range of modern technologies, yet their potential environmental impacts in gold mining regions are poorly understood. In this study, we collected soil samples from various locations within gold mining areas and analysed their REE contents using Neutron Activation Analysis (NAA), a precise and non-destructive method. To evaluate contamination levels and potential ecological harm, the enrichment factor (EF), geoaccumulation index (Igeo), and ecological risk index were applied.
Results revealed varying degrees of REE enrichment across sampling sites, with elevated EF values ranging from 0.20 to 2.70 and PLI values between 0.27 and 1.16 indicating no enrichment. Specifically, Eu and Tb showed the slight enrichment factors, might indicating an anthropogenic influence. The ecological risk index further indicated that 12.5% of the sampling sites might pose moderate ecological risks.
Overall, these findings underscore the importance of systematic REE monitoring and risk assessment in gold mining regions. Integrating REE analyses into environmental management strategies can help mitigate potential ecological impacts, ensure sustainable resource utilisation, and preserve environmental quality in these mineral-rich landscapes.
How to cite: Ahmed, M. E., Abbo, M. A., and Bounouira, H.: Integrating Neutron Activation Analysis and Multi-Index Assessments to Evaluate Rare Earth Elements in Sudanese Gold Mining Areas, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2493, https://doi.org/10.5194/egusphere-egu25-2493, 2025.
EGU25-18092 | Posters virtual | VPS17
Characterizing arsenic mineralization in the Carmen Quartz-Pyrite-Gold (QPG) Veins, Mankayan Mineral District, Philippines: A geometallurgical approachThu, 01 May, 14:00–15:45 (CEST) | vP4.18
Geometallurgy has emerged as a critical approach for understanding unconventional ore deposits, leveraging advanced techniques such as automated mineralogy and diagnostic leaching to characterize the behavior of complex ores. In the Philippines, the Carmen quartz-pyrite-gold (QPG) veins in the Mankayan Mineral District exemplify such a deposit, where copper occurs as arsenic-bearing tennantite and enargite. The ore's complexity is emphasized by intricate mineral textural relationships and its deleterious nature. Understanding its ore’s mineralization characteristics is imperative for the improvement of mineral processing and metal extraction.
The main orebody of the Carmen QPG vein is a silicic hydrothermal breccia intersected by multiple sulfide veins. Petrographic analysis reveals a predominance of tennantite with minor enargite-luzonite, closely associated with quartz and pyrite, the primary gangue minerals. Trace inclusions of chalcopyrite, bornite, chalcocite, and covellite are also observed replacing the primary minerals. Automated mineralogy, performed using a Mineral Liberation Analyzer (MLA) on whole and ground ore, provided valuable insights into the processing behavior of these arsenic-bearing minerals. Mineral maps of whole and comminuted samples reveal complex and pervasive textures at the microscopic scale. Tennantite is commonly associated with enargite (22.79%), pyrite (21.71%), and quartz (30.07%), while enargite is associated with tennantite (34.45%), pyrite (6.72%), and quartz (17.98%). Particle size distribution data indicate a convergence in the grinding behavior of enargite and tennantite with increasing fineness. Both minerals exhibit similar liberation trends, where larger size fractions contain a higher proportion of binary and ternary+ particles that progressively liberate with finer grinding. However, enargite consistently shows a higher proportion of liberated particles per size fraction compared to tennantite. Diagnostic leaching studies are currently underway to further evaluate the leaching behavior of arsenic, aiming to inform strategies for the effective beneficiation of this unconventional ore.
How to cite: Andal, K. G., Gabo-Ratio, J. A. S., Tungpalan, D. K. T., Manalo, P. C., and Taylan, R.: Characterizing arsenic mineralization in the Carmen Quartz-Pyrite-Gold (QPG) Veins, Mankayan Mineral District, Philippines: A geometallurgical approach, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18092, https://doi.org/10.5194/egusphere-egu25-18092, 2025.
