Mining, Volume 4, Issue 3 (September 2024) – 14 articles

This study aimed to evaluate the emergence, early growth, and anatomy of Schinus terebinthifolia Raddi cultivated in iron mining tailings. The seeds were obtained from trees used in urban afforestation and cultivated on two substrates: sand and iron mining tailings. The chemical composition of the mining tailing was characterized. The experiment was conducted in a growth room for 60 days. The emergence rate, seedling survival, height, number of leaves, chlorophyll content, and leaf and root anatomy were evaluated. The analysis of the composition of the mining tailings indicated that macro- and micronutrients were present, as well as potentially toxic elements such as Al, Cd, Cr, and Pb. The mining tailings reduced the emergence rate, and 25% of the seedlings died in this substrate. In addition, the mining tailings promoted a significant reduction in all parameters investigated, including seedling height, number of leaves, chlorophyll content, total leaf thickness, abaxial and adaxial epidermis thickness, palisade parenchyma thickness, and the length and width of the seeds. Additionally, the chloroplasts, the metaxylem vessel diameter, and the phloem proportion were evaluated. Interestingly, the tailings promoted an increase in the secretory channel. In the roots, no significant changes were observed in the parameters analyzed. Thus, the seeds of S. terebinthifolia germinated in the iron mining tailings, and 75% of the seedlings survived, showing their potential for reforestation. Nonetheless, iron mining tailings exhibited toxicity to S. terebinthifolia seedlings, reducing their photosynthetic tissues and, consequently, their growth; this toxicity is likely related to potentially toxic elements present in tailings. Full article

This study proposes a simple and replicable methodology to prioritize mining exploration projects based on their geoscientific characteristics and contextual factors, which can be adapted to different mining contexts. Using the Tiltil Mining District in Central Chile as a case study, where over 100 small and medium-sized Au and Cu prospects exist, this research outlines three key stages: (1) collection of relevant data; (2) selection of the most appropriate multi-criteria decision-making methods (MCDMs); and (3) the application, analysis, and comparison of these methods. This study identifies AHP and PROMETHEE II as the most suitable MCDM for the case study. The application of these methods consistently ranked El Huracán, San Aurelio, and La Despreciada as the top three exploration priorities. The AHP’s weight assignment highlights economic, geological, and social factors as the most critical variables in determining project viability. Full article

Given the global importance and limited availability of phosphate, optimizing the use of this critical resource and minimizing its wastage are of paramount importance. In this context, this paper proposes an innovative architecture for the implementation of an intelligent video surveillance system specifically designed for open-pit phosphate mines. The proposed architecture is designed to meet the overall functional requirements of a surveillance system in the challenging environment of open-pit mining, while aligning with the guidelines of the Mine 4.0 revolution. It incorporates advanced technologies that address the critical challenges of latency, data security, and transparency commonly encountered in traditional monitoring systems. By adopting a multi-layered approach that leverages edge, fog, and cloud computing, coupled with blockchain technology and expert collaboration, our architecture offers a comprehensive framework for efficient data processing at every stage, from initial data acquisition to real-time anomaly detection and decision-making. Full article

The planned closure of potash mines achieved through the injection of highly mineralized brines into the worked-out area is a complex process. A critical concern arises when brines obstruct the aerodynamic connections between the flooded mine’s airspace and the atmosphere, potentially leading to the formation of closed cavities where explosive gases can accumulate. To address this hazard, it is imperative to develop systems capable of extracting the gas–air mixture from the unflooded part of the worked-out area. Two distinct scenarios are examined: the first involves controlled flooding with saturated brines, while the second contemplates flooding resulting from a hypothetical breakthrough of supra-salt strata, leading to the ingress of groundwater into the worked-out area. A novel mathematical model is introduced to predict the evolution of gas–air mixture parameters in the unflooded part of the worked-out area. Utilizing this model, we assess the effectiveness of proposed measures designed to eliminate explosive gases from the worked-out area. Specifically, a pipeline system is proposed for the removal of gases. The findings from this study contribute valuable insights into ensuring the safe and efficient closure of potash mines, shedding light on potential risks and effective mitigation strategies for gas-related hazards during planned flooding. Full article

In this study, the static E₅₀ and υ parameters of rock materials were investigated using P-S wave velocities and Shore hardness (SH), using non-destructive measurement methods. In this study, the multiple linear regression (MLR), multiple non-linear regression (MNLR), and artificial neural network (ANN) models were used to estimate and determine the static E₅₀ and υ parameters. When comparing the models defined by MLR, MNLR, and ANN to the R² values, it was found that the ANN models, which estimate the E₅₀ and υ parameters of rock materials using non-destructive methods (V_p, V_s, V_p/V_s, ρ_d, and SH), achieved higher accuracy than the MLR and MNLR models. The originality of this study is rooted in the fact that ores such as galena, chromite, and barite were studied for the first time from a rock mechanics perspective, providing an innovative viewpoint. In addition, the use of all non-destructive measurement methods, V_p, V_s, and Shore hardness tests, also increases the importance of the study findings. Full article

Despite its vital importance to the contemporary economy, some drawbacks are mainly associated with waste derived from mining activity. This waste consists of tailings that are hydraulically disposed of in large impoundments, the tailings dams. As the dams are enlarged to accommodate higher amounts of materials, the stress states at which the deposited tailings are submitted change. This may be a concern for the stability of such structures once the geotechnical behavior of this material may be complex and challenging to predict, considering the existing approaches. Thus, the present study concerns the mechanical response of bauxite tailings under a wide span of stresses, ranging from 25 kPa to 4000 kPa. One-dimensional compression tests and isotropically drained and undrained triaxial tests were carried out on intact and remolded samples of the bauxite tailings. The after-shearing grain size distribution was characterized via sedimentation analysis. The results have shown a stress-dependency of the critical state friction angle for the intact material, which may be related to fabric alterations derived from structure deterioration and particle breakage. Overall, this research provides valuable insights into the response of structured and de-structured bauxite tailings, which are helpful for future constitutive modeling of such material. Full article

Despite the long tradition of mining activities in Kosovo, there is still the a lack of policies for post-mining. Specifically, focusing on coal mining, this research analyzes the sustainable transition and post-mining management in the Ruhr Region, exploring the potential for knowledge transfer to enhance mining practices in Kosovo. The research aims to identify transferable strategies for sustainable mining transitions by examining environmental, social, and economic dimensions. Through comparative analysis, the study assesses the applicability of Ruhr’s experiences in fostering environmentally responsible mining practices in Kosovo and beyond. Similarities and possible challenges are discussed based on the environmental and socio-economic points of view. The findings contribute insights into effective post-mining strategies, facilitating knowledge transfer to regions undergoing similar transitions and thereby fostering sustainable mining practices globally. Full article

Both the mineralogy and geochemistry of coal mine waste presents environmental and social challenges while simultaneously offering the potential source for recovery of metals, including critical raw materials (CRMs). Assessing these challenges and opportunities requires effective waste management strategies and comprehensive material characterization. This study deals with the integration of analytical data obtained from various portable sensor technologies. Infrared reflection spectroscopy (covering a wide wavelength range of 0.4 to 15 µm), and geochemical x-ray fluorescence (XRF) were utilized to differentiate between samples belonging to various geological lithologies and quantify elements of interest. Therefore, we developed a methodological framework that encompasses data integration and machine learning techniques. The model developed using the infrared data predicts the Sr concentration with a model accuracy of R² = 0.77 for the testing dataset; however, the model performances decreased for predicting other elements such as Pb, Zn, Y, and Th. Despite these limitations, the approach demonstrates better performance in discriminating materials based on both mineralogical and geochemical compositions. Overall, the developed methodology, enables rapid and in-situ determination of coal mine waste composition, providing insights into waste composition that are directly linked to potential environmental impact, and the possible recovery of economically valuable metals. Full article

Stopes suffer from unreliable wireless communication due to their harsh environment. There is a lack of confidence within industry regarding the effectiveness of existing solutions in providing reliable high-bandwidth performance in hard rock stopes. This work proposes that Wi-Fi6 is a good candidate for reliable high-bandwidth communications in underground hard rock stopes. Experiments in a tunnel and mine stope were conducted to evaluate the performance of Wi-Fi6 in terms of latency, jitter, and throughput. Different criteria, such as multi-hop systems, varying multipath, mesh routing protocols, and frequencies at different bandwidths, were used to evaluate performance. The results show that Wi-Fi6 performance is greater in stopes compared to tunnels. Signal quality evaluations were conducted using the Asus RT-AX53U running OpenWrt, and an additional experiment was conducted on the nrf7002dk running Zephyr OS to evaluate the power consumption of Wi-Fi6 against the industry standard for low-powered wireless communications, IEEE 802.15.4. Wi-Fi6 was found to be more power-efficient than IEEE 802.15.4 for Mbps communications. These experiments highlight the signal robustness of Wi-Fi6 in stope environments and also highlights its low-powered nature. This work also highlights the performance of the two most widely used open-source mesh routing protocols for Wi-Fi. Full article

This study examines how ESG risks and opportunities can be systematically identified, assessed, and incorporated into the early-stage design and planning of natural resources projects. The focus for this study will be on the mining activities required to source the resources for the global decarbonization effort. The need for a framework to incorporate ESG risks and opportunities into the strategic mine planning process was first identified in the de Beers Sustainability Valuation Approach. The Social Value Capital Decision Model advanced by BHP represents an advance on the de Beers model. This is the first example of a structured methodology for systematically considering stakeholder values and incorporating these into the capital decision framework. To test the applicability of a new approach to mine design by using Quality Function Deployment (QFD), a case study involving a copper mine located in South America was developed. This case study demonstrates how QFD can provide clear line-of-sight to connect design decisions with priority stakeholder concerns. The framework provides a communications tool for aligning the ESG design process across functional silos within complex organizations. The development of appropriate software tools could assist in managing the inherent complexity associated with integrating stakeholder value concerns into early stage design decisions. Full article

Underground hydrogen storage (UHS) is considered to solve the intermittency problem of renewable energy. A geological assessment indicated that the B unit of the Salina Group in Southern Ontario, Canada, is the most promising for UHS because it is the thickest and most regionally extensive salt rock deposit. However, the comprehensive geological knowledge of potential sites and overall salt volume for UHS remains undiscovered. This paper collected 1112 wells’ logging data to assess the geologic potential for UHS in Lambton County. The geological characteristic analysis of the B unit was conducted using high-frequency stratigraphic sequences and logging interpretation. The internal lithologies and thicknesses of the B unit were interpreted from 426 available wells. The storage capacity of the salt caverns was calculated from simplified cylinder models. The results indicate that the B unit can be subdivided into three high-frequency sequences, denoted as the SQ1, SQ2, and SQ3 subunits. SQ1 corresponds to salt–limestone, SQ2 corresponds to bedded salt rocks, and SQ3 corresponds to massive salt rocks. Well sections and thickness maps indicate that the study area can be divided into two sub-areas along the Wilikesport, Oil Spring, and Watford line. To the northwest, unit B was thicker and deeper in terms of paleo-water depth, and to the southeast, less of the B unit was deposited on the paleo-highs. The main thicknesses in SQ1, SQ2, and SQ3 range from 20 to 30 m, 25 to 35 m, and 30 to 40 m, respectively. In conclusion, the best subunit for UHS is SQ3, with a secondary target being SQ2. The main factor impacting cavern storage capacity for the SQ2 subunit is high mud content, while for SQ3, it is the meters-thick anhydrite developed towards the base of the unit. The available underground storage volume of the salt caverns in the B unit is 9.10 × 10⁶ m³. At the standard state, the working gas volume is 557.80 × 10⁶ m³. The favorable area for UHS is the western part surrounded by Wallaceburg, Oil Spring, and Watford. The thickness distribution of the B unit is the combined result of paleo-topography, sea-level changes, and tectonic movement in Lambton. The geological storage capacity of the salt caverns exhibits significant potential. Full article

Artisanal and small-scale gold mining (ASGM) has made several environmental impacts, resulting in the significant siltation of water bodies due to the deposition of sediments on riverbanks. Based on this perspective, this study aims to investigate the water bodies and regions most impacted by mining activities, especially in relation to the increase in the Total Suspended Solids (TSS) caused by ASGM, focusing on the territories of Suriname and French Guiana, over the period from 2017 to 2023, through the creation of an algorithm in Google Earth Engine. This research also aims to map and describe active mining in this region using the Classification and Regression Tree (CART) method, which achieved an overall accuracy of 82% and a kappa index of 0.77. The results reveal that from 2017 to 2024, there was an increase of 148.09 km² in mining, with an average increase in TSS of up to 167 mg/L in water bodies most affected by mining activities. Finally, the continued importance of using remote sensing technologies, such as GEE, together with innovative methodological approaches, to monitor and manage natural resources in a sustainable manner is highlighted. Full article

Heritage and culture tourism involve features that commemorate a valued past. Mining heritage tourism allows visitors to experience the past, guided by former mining landscapes and engaging interactively with material artifacts. This paper introduces the CoalHeritage European project, focusing on the promotion of coal mining heritage through the production and design of the European Visual Map Journal (EVMJ). The EVMJ is a user-friendly, web-based, interactive storytelling platform that supports the transfer of industrial and geoheritage from former coal mining areas. It aims to collect and disseminate heritage assets from post-mining coal areas, informing stakeholders and promoting these sites as tourist destinations. To further enhance public awareness, several ESRI StoryMaps web apps are being created to highlight specific features of each case study across Europe. The aim of this work is to introduce coal mining heritage as a new term, present the coal heritage platform and its importance for disseminating coal heritage aspects to the public, describe the methodology used for its design, and provide a brief overview of its evolving content. Full article

Groundwater quality can be impacted by the backfilling of coal pits with waste rock containing new mineral surfaces and nanomaterials. This study was implemented to identify newly available arsenic and selenium sources in waste rock from the Cordero Rojo Mine in the Powder River Basin, Wyoming, to highlight the alteration of contaminant sources with the transition from an overburden geologic state to the mined waste rock. Basic kinetic models were constructed to replicate the possible weathering modeling scenario derived from published sources of arsenic and selenium in the Powder River Basin overburden—pyrite and gypsum, respectively. These basic prediction models were unable to capture the arsenic and selenium trends recorded for a saturated column loaded with waste rock from the Cordero Rojo Mine. Enhanced kinetic models were tested through trial and error to capture newly available sources created by the mining of the waste rock. The incorporation of new source contributions produced modeled arsenic and selenium trends similar to the observed trends in water extracted from the column. The identification of newly available contaminant sources in backfill waste rock is necessary to evaluate the potential release of contaminants and the exceedance of water quality criteria for overburden formations that have not previously shown the potential for water quality contamination. Full article