Mining Infrastructure Research Articles

Coherence Alarm Implementation upon Post-Blast Impact in Open-Pit Mine

Slope Stability Radar (SSR) is a geotechnical monitoring tool, an array of sophisticated technology which is equipped with features that could be utilized in dynamic mining conditions. One of the features is called coherence and is used to track the impact of blasting activity around the research area. Historically, it has been recorded that fall-of-ground event (bench-scale failure) had occurred after blasting activity around the research area. These two events were recorded perfectly by utilizing coherence attribute measurement, including the time of event and the dimension of the impact area. Therefore, the application of a coherence alarm could be one of the solutions to provide an immediate response to track the blasting impact and provide periodic notification in case of the similar things occurred in the future. There are two alarm parameters in which required some adjustments due to the sensitivity of coherence attribute. The first one, is the alarm mask. It masks out the expected unwanted triggering alarm, such as vegetation area, ramp, machinery area, and mining infrastructures. The second one is the alarm threshold. It requires precise adjustment to maximize the alarm function during the rainfall event. The analysis resulting the threshold values advocated for the alarm are 12 contiguous pixels, 2 scans, and 0.6 coherence value. The alarm configuration parameters are then applied to the coherence alarm system. Notwithstanding that matter, the alarm configuration requires periodic adjustments, accompanied by the competencies of the person in charge for the SSR to be able to comprehensively understand the concept of coherence and its implementation in the research area.

An Overview of Possibilities of Increasing the Permissible Speed of Underground Suspended Monorails for Transporting People in the Conditions of Polish Underground Mining

The permissible speed of suspended monorails in underground mines is determined by the internal regulations of each country and depends on the type of transportation. In the case of passenger transportation, the maximal driving speed in Polish underground mining regulations is 2 ms−1. Regarding the higher permitted driving speed in other countries, it is reasonable to consider changes to these regulations that would raise the permitted speed limit. Increasing the permissible travel speed would improve the efficiency of mining operations because of the significant reduction in the inefficient working time of miners traveling on the monorail from the shaft to their place of work. However, at the same time, an increase in the permissible speed of travel results in higher values of forces and accelerations affecting both the crew riding the train and the underground working infrastructure (the suspended route, slings, and arches yielding support). The results of the series of works carried out at the KOMAG Institute of Mining Technology to assess the impact of increasing the speed on the safety of both the crew and the mine infrastructure are presented in this article. For this purpose, several numerical simulations were conducted, considering the emergency braking of the suspended monorail during which the overloads are the greatest. The result of the simulations was the analysis of the effects of driving and emergency braking of the suspended monorail with increased travel speed on the following: the overloads acting on the crew being transported and the forces acting on the suspended monorail route, including the forces in each sling. Next, a potential solution for improving safety was developed. The development of the algorithm for an innovative method of sequential emergency braking of the monorail in the case of passenger transportation was one of the important solutions.

Abandoned old mine excavation detection by Electrical Resistivity Tomography

Abandoned underground mine galleries or excavations in general pose important environmental and economic problems when a site is reactivated after being abandoned, because they might create risks for land stability. At the request of a need for a solution for the reopening of a mine (Horne 5 project of Falco Resources in Rouyn-Noranda, Quebec, Canada) future exploitation would start from 600 m deep. Before that reopening, it is very important to determine old mining excavation locations and conditions. The present study is targeting a technological challenge of detecting old and deep mining infrastructure. There is to date no application allowing the detection of underground tunnels or mining galleries at a depth of >80 m due to their depth and small size. Electrical Resistivity Tomography (ERT) is promising given its ability to image the contrasts between rocks and voids, whether these cavities are empty or filled with water or backfill materials. Several 2D and 3D ERT surveys were carried out to explore the abandoned old mining excavations. These ERT measurements highlighted the existence of old mining stopes, confirmed by the geotechnical boreholes performed on site, as well as two known galleries located at an approximate depth of 100 m. Overall, the results of this study highlight the potential of ERT approaches for the characterization of deep underground excavations.

Experimental Study and Mathematical Description of Gradation Effect on the Mechanical Characteristics of Crushed Waste Rocks

Crushed waste rocks, generated from mining operations, have been widely used for mining infrastructure constructions such as haul roads because of their low cost, high strength, and availability. Crushed waste rock gradation can, however, vary greatly, depending on blasting, mineralogy, and crushing process, but it is a key factor influencing the mechanical properties of crushed waste rocks (including resilient modulus, permanent deformation, and shear strength). Gradation should therefore be optimized to enhance their performance in the field. A series of repeated load and monotonic triaxial tests were carried out on crushed waste rocks with different gravel-to-sand (GS) ratios and fines contents (FC). Results showed that the optimum GS ratio was between 1 and 1.5 and contributed to provide higher resilient modulus and shear strength, and lower permanent strain. An increase in FC could, to the contrary, result in the decrease of resilient modulus and permanent strain and also a significant increase in shear strength. The structure state of crushed waste rocks was quantified using the cm model, and the mechanical properties of crushed waste rocks were dominated by sand and fines when the content of sand and fines was higher than 80%, while it was dominated by gravel particles as the content of sand and fines was lower than 60%. Here, the MR − θ model and the Rahman and Erlingsson model (extended using time-hardening approach) were well adapted to describe resilient modulus and accumulated permanent strain, respectively. Prediction models were also developed based on correlation analyses to predict the resilient modulus and permanent strain of crushed waste rocks based on gradation parameters.

Climate-mine life cycle interactions for northern Canadian regions

This study quantifies the impacts of climate change on the mine life cycle (development, operation and closure phases) of 30 mines located in the northern regions of Canada. To this end, climate projections based on a five-member transient climate change simulation ensemble, performed using a state-of-the art regional climate model, spanning the 1991–2050 period, corresponding to the Representative Concentration Pathway 8.5 emission scenario are used. A reanalysis-driven simulation for the 1991–2010 period compared against available observations confirm suitability of the model for application in climate change simulations. Assessment of projected changes to mine-relevant climate variables that are important from structural integrity and operation perspectives reveal potential vulnerabilities and opportunities. Active layer thickness increases in the 0.3–2 m range in permafrost regions, coupled with increases in flood probability, as reflected in snow-melt rate increases in the 0.14–6.77% range and increases in the 100-year return levels of daily maximum rainfall in the 5–50% range, suggest potential impacts on the structural integrity of mine infrastructure, such as slope instability and foundation settlement of tailings dams, and supporting infrastructure such as ice/all-season roads. Increases in soil moisture, projected in the 0–11% range, at a few mines, suggest potential impacts on material handling systems, such as increases in the traction factor of the muck-haul and tire rolling resistance, that can lead to low productivity. Projected increases to wind speeds in the 5–10% range for the northernmost regions suggest potential impacts on the tailings management facility in terms of increases in tailings resuspension. Overall, this study identified northernmost and northeastern mines to be more vulnerable, with air/soil temperature, precipitation and wind speed being the most influential climate variables. This systematic study, for the first time, has identified potential vulnerabilities of northern Canadian mines, which can inform future high-resolution climate modelling and detailed at-site climate-mine interaction studies that is required for climate-change adaptation related decision-making.

Herbestemming na de mijnsluiting. De ruimtelijke plangeschiedenis van Parkstad en het Emmaterrein, 1965-1997

Repurposing the Closed Coalmines. Spatial Planning in Parkstad and the Former State Mine Emma, 1965-1997. After the closing of the Dutch coal mines in the former Eastern Mining region in the south-eastern tip of the Netherlands, mining landscapes were wiped clean and industrial relics were all but completely demolished. The radical efficiency of this transition has, in current day, induced a public feeling of remorse over the lost physical proof of the mining period. This article traces how economic and programmatic parameters have guided spatial decision-making during the clean-up operation, and how was dealt with the possibility of preservation of mining relics. The article primarily analyses spatial planning documents responding to the closure of the mines, drawing forward the discourse underlying the restructuring of the region. Secondly, it discusses conceptualization, negotiation and problem solving targeted at the obsoleted mining infrastructure. Focusing on the terrain of former State Mine Emma, an intricate case in the light of this prevailing planning discourse, is put centre stage. The inflexible interdependence between a fixed spatial programme and a financial model is pinpointed as the key factor underlying the protracted redevelopment trajectory.

ЭКОНОМИЧЕСКИЕ ЭФФЕКТЫ ВНЕДРЕНИЯ ЭЛЕКТРОМАГНИТНЫХ ТЕХНОЛОГИЙ В НЕФТЕДОБЫВАЮЩУЮ ОТРАСЛЬ РЕСПУБЛИКИ БАШКОРТОСТАН

The article substantiates the importance of the implementation of the project for the introduction of methods for the development of oil fields based on the use of electromagnetic field energy to solve the problems of socio-economic development of Bashkortostan Republic in the conditions of the current state of the oil industry in the region. The author identifies the dependence of the socio-economic development of the republic on the state of the oil industry, identifies its key problematic points: low oil recoverability in the fields, as well as a high level of waterlogging of the extracted oil. The possibilities of covering the deposits of Bashkortostan Republic, suitable for the development of residual oil reserves, with electromagnetic technologies are determined. The conclusion is formulated about the expediency of introducing electromagnetic technologies in the deposits of Bashkortostan Republic in order to support the socio-economic development of the region. The results of the work can be used in the analysis of the prospects of regions with the predominant development of the oil production and refining complex. Further research may be devoted to assessing the immediate and delayed effects of the application of the considered and other innovative technologies in regions with a developed mining infrastructure. The study made it possible to formulate a number of conclusions: 1. The oil industry in Bashkortostan Republic is key for the socio-economic development of the region with various results of functioning: employment coverage, tax, investment aspects, etc. In addition, the oil-producing complex has a significant indirect impact on the socio-economic development. 2. Systematic reduction of oil production in the region leads to underutilization of its refining capacity, which is not compensated by oil coming from outside. The mining technologies currently used will not allow it to maintain an acceptable level in the future. The introduction of electromagnetic technology in depleted fields and, especially, in deposits of high-viscosity oil will allow to obtain significant volumes of oil in the near future. 3. The key effects of the introduction of electromagnetic oil production technologies for the socio-economic development of Bashkortostan Republic are the creation of jobs, expansion of the tax base, additional dividend payments and additional loading of existing refining capacities.

Tinjauan Terhadap Perencanaan Phytomining sebagai Alternatif Tambang Emas Ramah Lingkungan

The community's negative paradigm regarding mining activities is still circulating today. They assume that mining only brings harm to the surrounding environment. The community is worried that the mining activities carried out can damage the environment and make them lose their livelihood as farmers. Gold mining can not only be done by conventional methods, but also by the Phytomining method. Phytomining is the production of metal plants by growing plants that can accumulate metals in high concentrations. Phytomining is an environmentally friendly method because in the process it does not use chemical substances that can harm the environment and the surrounding community. In this study, mining planning is carried out which includes prospecting activities, exploration, feasibility studies (feasibility studies) equipped with Environmental Impact Analysis (AMDAL), mining preparation and construction of mining infrastructure, Occupational Health and Safety (K3), management and environmental monitoring. The Phytomining method used can be an alternative solution for environmentally friendly mining activities. In addition, the community will not lose their jobs and earn more because of mining activities. Mining with the Phytomining method has been widely applied in other countries, for that this method also has the potential to be developed in Indonesia.

INFRASTRUCTURE CATEGORISATION FOR RE-USE OF COAL MINE „LIPNICA“

Summary: In the northern synclinorium of Kreka coal basin, lignite mine ”Lipnica” was opened in 1950 in Lipnica settlement nearby Tuzla city. During the exploitation period, mine produced 40 million tons of lignite. By extracting the coal reserves, mine was shut down in 1991. Underground caves were filled by classical methods present in underground mining and all entries are sealed. The ground infrastructure remained preserved and has had usable values in three periods when infrastructure was used for various purposes. Conversion for re- use of mining infrastructure is not defined by any categorisation for infrastructure conversion use as the planning element of sustainable development for active or shutdown mines. The article defines categories of sustainable development based on utilizing mine infrastructure on the sample of “Lipnica” mine. The universality of categorisation points out the possible options of optimal re-use of coal mine infrastructure, indicating implementation of a mining company sustainable development concept, either in government or private ownership. Keywords: categorisation, sustainable development, business incubator, Lipnica mine

Hydroelectric Extractivism: Infrastructural Violence and Coloniality in the Sierra Norte de Puebla, Mexico

This paper argues that in Latin America, renewable energy and mining infrastructures are entangled in a logic of so-called green extractivism that rearticulates coloniality through infrastructural violence. It grounds the analysis in a case study of the Sierra Norte de Puebla, Mexico, where a logic of hydroelectric extractivism entangles small hydropower and mining projects. This co-articulation of extractivist and green transition imperatives reflects a reconfiguration of the Mexican political settlement to make natural resource extraction compatible with, and even necessary to, mitigating climate change. While presented as sustainable development by state and corporate actors, Nahua and Totonac land and environmental defenders resist these projects and call them proyectos de muerte to indicate that they threaten Indigenous lives, livelihoods, and territory. In analyzing this case study, the paper dispels the prevalent assumption that small hydropower plants cause minimal socio-ecological impacts. The findings also highlight the contested role of the state, illustrating that a state's infrastructural power can perpetuate coloniality and infrastructural violence while also enabling political activism to effectively challenge them. The focus on small and sustainable infrastructure contributes to burgeoning research on green extractivism, while the emphasis on power relations challenges much of the current literature on energy and sustainability transitions.

Toward a Reconfiguration of Mining Infrastructure in Mexico: Norms, Resistance, and Governance

This paper offers an analytical framework to identify how communities that have been negatively affected by mineral extraction and its infrastructure can begin to transition toward an emancipatory approach to overcome their marginalization, which has been accentuated by the socio-environmental conflicts caused by mining. We argue that through the extractivism–infrastructure nexus, alternative options to overcome these conflicts can be unveiled and unpacked. By comparing two Mexican mining cases—the Sonora River region in the northwest of the country and the Oaxaca highlands in the southeast—we identify the instances of everyday resistance, struggle, and contestation that are important to assessing emancipation. The cases show how non-Indigenous communities, inspired by Indigenous groups, can begin to think differently and move toward a transition that is more socio-environmentally just. Building on interlegal and municipalism debates, we argue that this transition can be accomplished through a focus on narratives, practices, and norms within four analytical factors: normative frameworks, legacies of social movements, local governance, and alternative economies. Our argument offers an alternative way to investigate the function infrastructural projects have in municipal policy-making.

Metaheuristic Approach to Synthesis of Suspension System of Mobile Robot for Mining Infrastructure Inspection.

The article describes the problem of geometric synthesis of the inspection robot suspension system, designed for operation in difficult conditions with the presence of scattered obstacles. The exemplary application of a mine infrastructure inspection robot is developed and supported by the ideas. The brief introduction presents current trends, requirements and known design approaches of platforms enabled to cross the obstacles. The idea of a nature-inspired wheel-legged robot is given, and the general outline of its characteristics is provided. Then the general idea of kinematic system elements selection is discussed. The main subject of geometrical synthesis of the chosen four-bar mechanism is described in detail. The mathematical model of the suspension and connections between the parts of the structure is clarified. The well-known analytical approach of brute force search is analyzed and validated. Then the method inspired by the branch and bound algorithm is developed. Finally, a novel application of the nature-inspired algorithm (the Chameleon Swarm Algorithm) to synthesis is proposed. The obtained results are analyzed, and a brief comparison of methods is given. The successful implementation of the algorithm is presented. The obtained results are effectively tested with simulations and experimental tests. The designed structure developed with the CSA is assembled and attached to the prototype of a 14-DOF wheel-legged robot. Furthermore, the principles of walking and the elements forming the control structure were also discussed. The paper is summarized with the description of the developed wheel-legged robot LegVan 1v2.

Application of Good Mining Practice at PT. Gunung Bale, Malang, East Java

This study aims to determine the application of Good Mining Practice at PT. Bale Mountain. Mining activities at Gunung Bale consist of processes: Stripping and Top Soil Management, Mining Production Operations, Stock Pile Activities, Quality Control and Transportation to Consumers. The methodology used is a study of the application of Good Mining Practice. Data and information are processed and tabulated for later analysis descriptively and quantitatively. The results showed that the Mining Technical PT. Gunung Bale uses the open pit mining method with a Quarry mining system with a site hill type and a pit type. Mineral conservation is carried out using the method of calculating the volume of resources and reserves with the Triangular method using the Block model concept (software used is SURPAC 6.6.1). To prevent work accidents at the mine site, warning signs are installed and Personal Protective Equipment (PPE) and first aid kits are provided. Every time starting mining activities, a safety talk is held with the workers. Environmental management includes waste management, restoration and monitoring of water quality, handling of acid mine drainage, revegetation, and making a reclamation plan. The main mining infrastructure for road construction cuts around ±2 Ha. The total length of the road is 2,731 m. Processing and refining facilities are not located in the mining area.

The role, importance and impact of the methane hazard on the safety and efficiency of mining production

Abstract Underground mining production is an extremely important process for the economy and carried out in very difficult and complex environmental conditions. The disturbance of the balance of this environment makes it also a very dangerous process. Due to the importance of coal, mainly as an energy raw material, the process of its exploitation is carried out all over the world. The specificity of its production is mainly determined by mining and geological conditions, which determine the method of operation and the selection of machines and devices for this process. One of the most dangerous natural hazards associated with this process are ventilation hazards, including methane hazard. The reason for this threat is methane, an odorless and colorless gas, which becomes a flammable and explosive gas under certain criteria. These features make this gas a huge threat to mining operations. Its huge amounts, contained in coal seams, are released into the mine atmosphere during the exploitation process, causing a very high threat to work safety. Events related to the occurrence of methane are most often the cause of mining disasters, in which people die and the technical and mining infrastructure is destroyed. The reason for the growing methane hazard is the increasingly difficult mining conditions, and mainly the increasing depth of mining, and thus also the increase in methane-bearing capacity of the seams. Taking into account the huge impact of methane hazard on the mining process, the article discusses its impact on the safety and efficiency of this process. The results of the literature review with regard to this risk are presented and the accident statistics are presented. On the basis of actual data, an analysis of interruptions in the exploitation process related to exceeding the permissible methane concentrations was carried out in one of the mines. The problem of limiting the production process due to these exceedances is an important factor reducing the efficiency of this process. The obtained results clearly indicate that the losses resulting from these breaks deteriorate the profitability of the entire process and affect the economic efficiency of the industry. In order to effectively counteract the dangerous phenomena related to the methane hazard and to improve the efficiency of the mining production process, solutions were proposed to improve this state and the directions for further research were proposed.

Long-term Indonesia’s Nickel Supply Chain Strategy for Lithium-Ion Battery as Energy Storage System

The world energy demand is as high as ever, carbon-based energy such as oil, gas, and coal are the primary energy supply used to cope with the demand. The threat of climate change became more evident as the world population from across the world began to feel the impact. The rapid rate of sustainable energy sources such as solar and wind needs an energy storage system, as such sources of its energy are not always available. One of many kinds of energy storage system is lithium-ion battery. The demand for lithium-ion batteries reflects the world's demand for sustainable energy, making material for Lithium-ion batteries the new oil. Nickel in Lithium-ion battery is one of significant materials used to make this battery. Indonesia has been one of the world’s top producers of nickel and has the most reserve in the world. Most Indonesian nickel has been exported as raw ore to be processed in other countries. Recognizing its potential, the government has been imposing a law banning the export of raw nickel ore. The government constructs smelters to purify the ore to get a higher nickel content. But still, Indonesia has issues to work on so its plan will proceed as intended. Issues such as extensive political involvement, complicated government bureaucracy, and inconsistent policies and laws. The big investment in mining infrastructure must align with the investment in the people who will manage it and who are going to execute the actual plan.

Impact of suspension and route stabilization on dynamic parameters of self-driven mine suspended monorails

Impact of the method of suspension and route stabilization of suspended monorail on forces loading the roadway roof support system is presented. This is important in the context of possible increasing the speed of monorails during personnel movement. Nature of load and displacement of the route, as well as deceleration of the transport set, with a dynamic excitation - an emergency braking of the transport set, are presented. The results are presented for seven configurations of slings and lashings stabilizing the route. The Head Injury Criterion (HIC), recorded using the Articulated Total Body (HYBRID III) model, during the impact of operator's cabin against an obstacle, is presented in the further part of the article. Analyzes are aimed at developing the guidelines to ensure safety of mining personnel (without exceeding the accepted overloads) and mining infrastructure (without exceeding the maximum accepted load of the roadway support) during operation of the suspended monorail at higher speed. Analyzes are the result of the authors numerical simulations.

Structure and analysis of the mining subsector from the national energy sector in the context of stability and increase of Romanian energy security

Until recently, the European Union's energy policy was against coal for pollution reasons, but with the start of the military war between Russia and Ukraine, coal has become one of the energy resources to reconsider. The lack or depletion of oil and natural gas from Russia has made the coal resource the most important source and means to provide energy security. Because there are many coal-fired power stations in Romania (hard coal and lignite), its extraction and recovery becomes a real problem of national security, because it produces electricity, which is vital to Romanian society. The need to analyse the mining subsector, which generates critical mining infrastructure, comes in the context in which the possible occurrence of cases of non-energy supply, or unexpected price increases, generates major issues of national interest, with European and OTAN implications. The aim of the paper is to structure and analyzse the mining subsector within the National Energy Sector in the context of stability and increasing national energy security. The authors consider that the approach of the mining subsector is a strictly national security issue because the lack of coal can cause damage to the power sector and the national economy, which are partly dependent on the mining subsector.

A GIS-based multi-hazard assessment at the San Pedro volcano, Central Andes, northern Chile

Recent advances in the modeling of volcanic phenomena have allowed scientists to better understand the stochastic behavior of volcanic systems. Eruptions can produce various types of volcanic phenomena of different sizes. The size of a given volcanic phenomenon dominates its spatial distribution and is commonly represented by volume/mass parameters in the models that reproduce their behavior. Multi-hazard assessments depend on first-order parameters to forecast hazards at a given geographic location. However, few multi-hazard assessments consider the size of the eruption (e.g., tephra fallout) to co-parameterize the size of the accompanying phenomena (e.g., mass flows) in a given eruptive scenario. Furthermore, few studies simulate multi-phenomenon eruptive scenarios with semi-continuous variations in their size, something that allows a better quantification of the aleatoric variability of the system. Here, we present a multi-hazard assessment of the San Pedro volcano, a high-threat volcano from northern Chile, that produced two large-size Plinian eruptions (VEI 5 and 6) in the last 16 ka, and ten Strombolian eruptions (VEI 2) between 1870 and 2021 CE, with the latest occurring on 2 December 1960 CE. We use intra-scenarios (i.e., subdivisions of eruptive scenarios) to explore the size variability of explosive volcanic phenomena. The size of intra-scenarios is extrapolated from the largest-size deposits of each type of phenomenon from the geologic record of the San Pedro volcano. We simulate explosive intra-scenarios for tephra fallout, concentrated PDCs, and lahars, and effusive scenarios for blocky lava flows. On the local scale, mass flows are likely (66–100%) to affect transport and energy infrastructure within a 14 km radius of the volcano. On the regional scale, large-size eruptions (VEI 5) in the rainy season are about as likely as not (33–66%) to accumulate 1 cm of tephra on energy, transport, and mining infrastructure over a 50 km radius, and these same eruptions are unlikely (10–33%) to accumulate 1 cm of tephra on the city of Calama. This work shows how multi-phenomenon intra-scenarios can be applied to better quantify the aleatoric variability of the type and size of volcanic phenomena in hazard assessments.

Anthropogenic land use and urbanization alter the dynamics and increase the export of dissolved carbon in an urbanized river system

Greenhouse gas emissions from urban rivers play a crucial role in global carbon (C) cycling, this is tightly linked to dissolved C in rivers but research gaps remain. The effects of urbanization and anthropogenic land-use change on riverine dissolved carbon dynamics were investigated in a temperate river, the River Kelvin in UK. The river was constantly a source of methane (CH4) and carbon dioxide (CO2) to the atmosphere (excess concentration of CH4 ranged from 13 to 4441 nM, and excess concentration of CO2 ranged from 2.6 to 230.6 μM), and dissolved C concentrations show significant spatiotemporal variations (p < 0.05), reflecting a variety of proximal sources and controls. For example, the concentration variation of dissolved CH4 and dissolved CO2 were heavily controlled by the proximity of coal mine infrastructure in the tributary near the river head (~ 2 km) but were more likely controlled by adjacent landfills in the midstream section of the rivers main channel. Concentration and isotopic evidence revealed an important anthropogenic control on the riverine export of CO2 and dissolved organic carbon (DOC). However, dissolved inorganic carbon (DIC) input via groundwater at the catchment scale primarily controlled the dynamics of riverine DIC. Furthermore, the positive relationship between the isotopic composition of DIC and CO2 (r = 0.79, p < 0.01) indicates the DIC pool was at times also significantly influenced by soil respiratory CO2. Both DIC and DOC showed a weak but significant correlation with the proportion of urban/suburban land use, suggesting increased dissolved C export resulting from urbanization. This research elucidates a series of potentially key effects anthropogenic activities and land-use practices can have on riverine C dynamics and highlights the need for future consideration of the direct effects urbanization has on riverine C dynamics.

Cost‐effective in‐mine seismic experiments to image platinum deposits and associated geological structures at Maseve platinum mine, South Africa

ABSTRACTThe detection of mineral deposits and their related geological structures is of great importance to the mining industry as structures (such as dykes and faults) can affect the safety, cost and efficiency of mining. With the goal of testing cost‐effective seismic methods for mineral exploration and mining, active and passive seismic experiments were conducted at Maseve platinum mine in the Bushveld Complex (South Africa) in 2020. The experiments involved surface‐passive (using 5 Hz wireless nodes; single vertical component) and in‐mine active reflection seismic surveys (using 4.5 Hz land streamer and 5 kg sledgehammer) to image geological structures and delineate economic platinum‐group elements bearing Merensky and Upper Group‐2 chromitite layers (known as reefs). This paper presents only the results from the in‐mine active seismic experiments. The in‐mine seismic surveys consisted of seven 2D reflection seismic profiles in the development tunnels, which were located ∼550 m below ground surface and a few tens of metres above known mineralizations: the Upper Group‐2 and Merensky Reef. The data were carefully processed to enhance the reflections and suppress noise generated by mine infrastructure (e.g., equipment and ventilation). We successfully imaged the Merensky Reef and Upper Group‐2 orebodies approximately 55 m and 124 m below the tunnel floor, respectively, and delineated faults and dykes that crosscut them. Furthermore, the seismic data reveal relatively strong amplitude and faulted reflections below the Upper Group‐2 that may represent deeper chromitite‐enriched orebodies. However, the economic value of these horizons can only be confirmed through drilling. The processed seismic data were combined with borehole data, synthetic modelling and geological models to constrain the interpretation. This study encourages the use of in‐mine seismics for future mineral exploration, mine development and planning.