Opencast Mining Operations Research Articles

Multidisciplinary evaluation of geological, geotechnical, geomechanical, and hydrogeological parameters for assessing slope stability in the Aures Mountain Quarry

The study delves into characterizing the mechanical parameters of the Tahar Louchene aggregate quarry unit in Ain Touta municipality, Batna province, Algeria. This investigation is crucial to address recurring instabilities commonly encountered in open-cast mines. Our approach adopts a comprehensive methodology integrating geotechnical, geomechanical, and numerical analyses, aiming to provide a thorough assessment of fractured rock mass behavior. Our methodology begins with detailed geological surveys aimed at optimal drilling site selection. Geomechanical analysis follows, focusing on fracturing and evaluating rock mass quality, complemented by geotechnical investigations featuring in-situ testing. To gather representative samples, we extracted eighteen cylindrical cores (102 mm × 204 mm) from various benches using a mechanical coring drill. These cores underwent rigorous physical characterization, geochemical analysis, and mechanical testing. Furthermore, 3D FEM numerical modeling was applied to comprehensively assess rock edge stability. The outcomes of our study unveil the presence of four distinct discontinuity sets within the primary formations, with particular emphasis on fault families of geological significance influencing deposit configuration. These fault structures provide valuable insights into stress history and tectonic evolution that directly impact the stability of the quarry. Moreover, our analysis identified various failure types, notably exacerbated by blasting practices that reduce safety factor values, highlighting the critical need for improved safety protocols. Our approach not only contributes to enhancing mining efficiency and productivity but also prioritizes the safety of equipment and personnel in open-cast mining operations across Algeria.

Solar Ultraviolet Radiation Exposure Among Opencast Miners in Namibia with the Use of Electronic Dosimeters: A Feasibility Study.

Importance: The lack of information on exposure of opencast mineworkers to solar ultraviolet radiation, a group I carcinogen, was addressed. The feasibility of using electronic dosimeters in the determination of exposure to solar ultraviolet radiation was investigated. Objective: The objective of the study was to determine the feasibility of measuring the occupational exposure of opencast mineworkers to solar ultraviolet radiation using electronic dosimeters. Design: The study followed a cross‑sectional design. Setting: Measurements were carried out at two opencast diamond mining operations hereafter referred to as site A and B, located in the Karas region of Namibia. Participants: Workers from all four outdoor occupations (bedrock, engineering, metallurgy and security) were recruited to participate in the study. Measurements: The study was conducted over four days at each site during winter (site A: 28 June to 4 July 2018 and site B: 6-11 July 2018) in the Karas region of Namibia with 28 consenting workers taking part. The AlGaN photodiode‑based electronic dosimeters were worn above clothing on the dorsal wrists (one) and two placed on the horizontal, unshaded area from 08:00 to 16:00 for the measurement of personal and ambient solar ultraviolet radiation, respectively. Historical meteorological data for the measurement period were obtained from Solcast and Ozone Monitoring Instrument (OMI) NASA. Results: Overall, clear skies and surface reflectivity of 0.19 were observed for both study sites. The mean ultraviolet indices were 2.43 (0.06-4.51) and 2.24 (0.09-4.88) for site A and B, respectively. Findings of valid measurements from nine participants showed the mean total daily personal solar ultraviolet radiation exposure of 1.9 ± 1.0 (1.01-1.57) standard erythemal dose (SED) for site A and 3.4 ± 2.6 (3.39-7.28) SED for site B. Conclusions and Relevance: Personal solar ultraviolet radiation exposure above the occupational exposure limit (OEL) demonstrated the need to include the winter season in planning for protective measures for skin and eyes, since workers are at risk of excessive exposure to solar ultraviolet radiation.

Strategies for Sustainable Mine Reclamation: Case Study of the Meghahatuburu Iron Ore Mine

ABSTRACT The demand for raw materials is increasing rapidly, leading to higher production targets for mining industries. Currently, largescale opencast mining operations are causing extensive damage to forest areas, agricultural land, and various habitats for humans and animals. Despite these negative impacts, mining plays a crucial role in our national economy, serving as the second backbone of the country after agriculture. Given the inevitability of mining operations, it is essential to carry them out in a sustainable manner, minimizing or even eliminating environmental harm. This study focuses on the challenges associated with iron ore mining and emphasizes the significance of ecological restoration and land reclamation in mitigating environmental consequences. The focus of this research work is the implementation of a comprehensive procedural approach to achieve sustainable mine reclamation in an easy way. The primary objective is to restore the biodiversity of the Saranda Forest ecosystem. To accomplish this, a three-tier plantation model was adopted, involving the strategic planting of 2,664 trees and 3,136 herbs/shrubs in 1.5 hector degraded backfilled area. This initiative aims to rehabilitate the degraded land that has been adversely affected by mining activities.

Spatial assessment of air pollution due to mining and industrial activities: a case study of Kryvyi Rih, Ukraine

Air pollution has remained a primary concern over the last decades. Respirable particulate matters (PM) PM2.5 and PM10 are the main atmospheric pollutants that have an adverse effect on human health. This study aimed to examine the air quality of Kryvyi Rih region through the spatial assessment by means of Ordinary Kriging. The study region has a major iron ore basin with several open cast mining operations and industrial activities, which are mainly contribute to the environmental issues. For the study, 10 monitoring stations were chosen located around the main residential and industrial areas of the city. The results showed that industrial plants were the largest sources of PM emissions. The average Air Quality Index (AQI) of PM2.5 and PM10 for the observed period obtained from the station located in close vicinity to the industrial plants were 170 and 89 respectively. Additionally, the 48 hours of PM dynamics were graphically analysed. It was found that PM reaches a peak primary between 12 AM and 12 PM before falling a little between 12 PM and 12 AM.

Risks and challenges affecting opencast pillar mining in previously mined underground bord and pillar workings

South Africa is one of the leading producers and exporters of coal globally. A significant amount of the country's production is obtained from previously mined underground bord and pillar workings. This coal is in the form of pillars and remnants on the roof and floor of the old workings. The good quality coal pillars were left behind as primary support during underground bord and pillar mining operations. Due to the depletion of virgin coal reserves, the pillars and remnant coal are now removed using opencast mining rather than underground methods. However, the secondary extraction of pillars and remnant coal from the old workings using opencast methods entails some serious challenges that have a negative impact on the safety and productivity of the operations, affecting both personnel and machinery. If these risk factors and challenges are managed properly, then the opencast mining operations could remove the pillars safely at recoveries competitive with those of virgin coal operations. In this study we review the recurring challenges affecting opencast pillar mining by means of field investigations and consultations with experts at five opencast pillar mining operations, and evaluate the best practices used to combat these challenges. It was found that each mine has its own unique conditions and challenges.

Prediction of Mining Conditions in Geotechnically Complex Sites

Geotechnical complexity in mining often leads to geotechnical uncertainty which impacts both safety and productivity. However, as mining progresses, particularly for strip mining operations, a body of knowledge is acquired which reduces this uncertainty and can potentially be used by mining engineers to improve the prediction of future mining conditions. In this paper, we describe a new method to support this approach based on modelling and neural networks. A high-level causal model of the mining operations based on historical data for a number of parameters was constructed which accounted for parameter interactions, including hydrogeological conditions, weather, and prior operations. An artificial neural network was then trained on this historical data, including production data. The network can then be used to predict future production based on presently observed mining conditions as mining proceeds and compared with the model predictions. Agreement with the predictions indicates confidence that the neural network predictions are properly supported by the newly available data. The efficacy of this approach is demonstrated using semi-synthetic data based on an actual mine.

Artificial intelligent based smart system for safe mining during foggy weather

AbstractOpencast mining operations at hilly areas are usually affected during foggy weather due to the inability of drivers to operate heavy earth‐moving machinery in low visibility conditions. This article deals with an intelligent vision enhancement system for continuing opencast mining operations during foggy weather. The system integrates hardware and software to provide multistage safety features that make it unique from existing systems. The system includes hardware like thermal cameras, high definition cameras, proximity radar, wireless devices, GNSS module, graphical processing unit, display unit, and so forth, and image processing software, namely real‐time image stitching, image enhancement, and object detection using convolutional neural networks. The integrated system and algorithms display a 180° panorama field view of the vehicle's front using real‐time video stitching. The front view after image processing, rear camera view, object detection through proximity radar, and real‐time location of the vehicles on a 3D geo‐tagged mine map by GNSS modules are displayed in four splitter windows on a touch screen fitted on the dashboard in front of the driver's seat. The driver can drive the vehicle by seeing the display screen during foggy weather. The output image of the developed image‐processing algorithm has less distortion, better quality, and better depth perception than existing methods. Overall, there are significant improvements in the persistence of the color elements by 39.65%, contrast by 4.62%, and the corresponding entropy by 7.11% concerning the similar existing methods. The final system has been successfully tested in an opencast mine.

Assessment of dispersion of respirable particles emitted from opencast mining operations: development and validation of stepwise regression models

Assessment of dispersion of respirable particles emitted from opencast mining operations: development and validation of stepwise regression models

Reconstructing an ancient mining landscape: a multidisciplinary approach to copper mining at Skouriotissa, Cyprus

Extensively worked in antiquity, Skouriotissa remains the only active copper mine on the island of Cyprus. The modern, open-cast operation, however, has almost completely obliterated the earlier mining landscape. Here the authors report the results of investigations, including dating, of the ancient topography of the mine. They incorporate spatial data derived from archival sources, recent fieldwork and absolute dating into a geographical information system to reconstruct the ancient mining landscape around Skouriotissa. Their approach holds promise for understanding other mining regions in Cyprus and beyond, by providing an example of how diverse source material can be used to reconstruct landscapes now destroyed or buried by open-cast mining operations.

“A cancer on the planet”: Mountaintop Removal and Environmental Crime in Jonathan Franzen’s Freedom

The American novelist Jonathan Franzen has always shown a great interest for the environmental problems, mainly in his masterpiece Freedom (2011) and in the essay “My Bird Problem” (2005). Freedom, which recounts three decades of the Berglund family, sees its main character dealing with the environmental themes for his work. Walter is a lawyer who is actively engaged in environmental causes, but the one that occupies most of the novel, is the support of an organization called “Cerulean Mountain Trust”, which aims at saving the cerulean warblers, a small species of songbird, creating a “birds’ sanctuary” in West Virginia. The honorable cause is actually moved by Vin Haven, a Texan millionaire tycoon who wants to implement an extractive coal strip mining operation and afterwards build the birds’ sanctuary as a remedial move. The aim of this paper is to analyze the novel to extract Franzen’s fictional depiction of actual environmental crimes in order to shed light on harmful practices such as the mountaintop removal.

Development of statistical models to predict emission rate and concentration of particulate matters (PM) for drilling operation in opencast mines

Air pollution in mining area is one of the critical concerns because of the generation of large amount of the particulate matters (PM) in opencast mining operations. The emission of PM in the air not only deteriorates the surrounding environment but also impacts adversely to the human health. The majority of the PM particles in opencast mining comprise PM2.5 and PM10. The assessment of the limit of the PM particles is very important as it helps in environmental impact analysis (EIA/EMP) and prediction of possible dust generation (PM particles) for any project to be established. In this paper, a model was developed that is capable to predict the respirable dust particulate concentration in the ambient air at various locations near and away from the dust-generating source, especially from a drilling operation in Indian opencast mines. The modeling was carried out using three different methods, i.e., “SPSS,” “R,” and artificial neural network (ANN) methods. Results from these developed models were compared with the US Environmental Protection Agency (USEPA) model for its validity. The predicted values from the developed model showed good correlation and the least variation from the field-monitored values, indicating better accuracy, compared with other models.

Technical evaluation of Off-Earth ice mining scenarios through an opportunity cost approach

In this paper, four Off-Earth Mining scenarios for water extraction have been designed to supply a H2/LOx propellant market in Low Earth Orbit. A non-financial measure for determining feasibility has been devised for the analysis based on the opportunity cost as opposed to the Net Present Value. The first scenario for evaluation is a conventional strip mining operation in a southern lunar crater. An ‘In-Situ Sublimation’ method in the same location has been determined to be more competitive than strip mining due to equipment mass requirements. However, neither system can compete with direct launch of water from the Earth based on the assumptions in this research. The third and fourth scenarios are based on a near Earth dormant comet and also utilize In-Situ Sublimation techniques. These scenarios focus heavily on transport optimization. A single miner-hauler system was found to be inferior to the multi-craft system. It was also revealed that the dormant comet mining scenarios will not be competitive enough with lunar mining or direct launch from Earth to supply a Low Earth Orbit market.

Soil fertility analysis in and around magnesite mines, Salem, India

ABSTRACT The opencast mining operations have periodical effects in surrounding landscape and it is important to monitor the quality of the soil. The pre- and post-mining activities influence the soil quality due to removal of vegetation and topsoil cover. The low-grade magnesite ores and dumping of waste materials are the root causes of contamination of soil. The samples collected from the depth of 15 cm on the surface of soil with different physical (soil texture and soil moisture) and chemical (pH, organic carbon, and nitrogen) parameters are analyzed to study the effect of opencast mining on the surrounding soil. Nine soil samples collected from three magnesite mine sites include agriculture land in close proximity. The result of this analysis predicts the sample soils deficiency of nutrients contents like nitrogen, phosphorus, potassium, and calcium. The soil analysis comprises chemical parameters such as pH, lime status, texture, electrical conductivity, available macronutrients nitrogen (N), phosphorous (P), potassium (K), and micronutrients such as Fe, Mn, Zn, and Cu percentages which are used to determine the condition and quality of the soil. The STATISTICA software (ver.8) was used for analysis of Pearson’s correlation with linear relationship of soil samples and rows and columns of data matrix on cluster analysis.

Study on assessment of slope stability and mixed disposal of overburden in voids of Singrauli Coalfield

AbstractThe mining industry can be considered the backbone of the Indian economy as well as facilitating the power that drives most of the other industries in the company. The overburden and waste rocks produced during coal mining are major concerns in regard to the amount of land that is required for their disposal, as well as the stability of dumps for these materials, which are of increasing height. Land reclamation issues are also a concern. In this work the adverse impacts caused by the dumping of overburden on land and acidic mine water on water bodies is discussed. Remote sensing tools were used along with the laboratory experimentation to assess the various impacts. This study also shows that silt released from waste dumps, can affected the angle of repose of the overburden dump slope. The angle of repose of the overburden materials varies with particle size composition. Thus, use of in‐pit crushers in large opencast mining operations can effectively reduce the area locked under the waste dumps. The acid neutralization potential of fly ash and overburden for the treatment of acid water was tested in the laboratory by using fly ash and waste rock materials on acidic coalfield water. The results are encouraging, and fly ash may prove to be a good acid neutralizer when used in conjunction of coal overburden material.

Methodology for assessment and analysis the geomechanical state of the opencast mining operations built up in the rock masses

Methodology for assessment and analysis the geomechanical state of the opencast mining operations built up in the rock masses

A system-wide approach to minimize the operational cost of bench production in open-cast mining operations

The production cycle of open-cast coal mines generally includes drilling, blasting, loading, hauling and coal preparation activities. Individual optimization of these activities does not mean that the whole system is optimized. This paper proposes a cost model considering all activities in mining cycle and system-wide approach to minimize the total mining cost of bench production. Since the fragmentation size and blast-hole diameter are linked to all activities of mining system, they are considered as decision variables in the problem formulation. The operation costs are then minimized by using the evolutionary algorithm. Moreover, the impact of the change in the explosive price, and the hourly unit cost of equipment on total mining cost is quantified by sensitivity analysis. A case study is implemented to demonstrate the developed model.

Hydrological characterization and prediction of flood levels of acidic pit lakes in the Tharsis mines, Iberian Pyrite Belt

Opencast mining operations frequently lead to the creation of large voids that become anthropogenic lakes when the water table recovers. In the case of sulfide mining the stored water is of an acidic nature with significant concentrations of toxic metals and, therefore, a high pollutant potential. The main goal of the present work is to characterize the hydrological functioning and evolution of four acidic mine pit lakes in the abandoned mines of Tharsis, which is the second most important mine district in the Iberian Pyrite Belt (IPB). We present a simple methodology based on the use of the available orthophotographs and a Digital Terrain Model (DTM) together with the water balance of the pit lakes, which could be applied to other abandoned mining sites, where there is often a lack of hydrogeological information that prevents the application of more complex models. The accumulation of large volumes (5.2 × 106 m3) of acidic and metal-rich waters in these pit lakes poses a serious environmental concern, with dissolved concentrations up to 2000 mg/L of Fe, 223 mg/L of Al, etc. Sierra Bullones and Filón Norte are connected underground and present the same evolution, with water transfers from Sierra Bullones to Filón Norte. The water level in both pit lakes is increasing, with an average rise of 2.8 m/yr since the beginning of flooding. However, the increase in the evaporation rate, as a result of the larger flooded area as the water level rise, would induce a hydrological equilibrium before reaching the overflow level, leading to the formation of a terminal lake. On the other hand, the water level in Filón Centro and Filón Sur pit lakes remain approximately stable. The first behaves as a flow-through or terminal lake, depending on the annual rainfall, while the second acts permanently as a flow-through lake.

In the shadow of the coal breaker: cultural extraction and participatory communication in the Anthracite Mining Region

ABSTRACT What stories do ruins tell? What is the legacy of the extractive coal industry? When is extraction complete in a single-industry area? Tied to global capital, fuelling the Industrial Revolution on the labour immigrants, the legacy of extraction in the Anthracite Coal-Mining Region in Northeastern Pennsylvania extends into local notions of heritage, memory, community welfare, and place. Tracking (de)industrial life scenes in the Anthracite Coal-Mining Region, this ethnographic work follows traces of the past as they emerge and the day-to-day practices that sustained them noting intensities and flashpoints as they arise in daily life. As a particular flashpoint, Coal Region residents processed the demolition of the ruins of Saint Nicholas Coal Breaker, the last anthracite coal breaker built before 1960 and once the largest coal breaker in the world. Residents rapidly produced and shared digital media of the Breaker with and through a large public digital humanities collaboratory that I created and maintain through an active Facebook page (https://www.facebook.com/AnthraciteCoalRegion) of more than 8000 members and a corresponding website. Engaging in community dialogue, participatory communication, and offering critical interpretations, residents wrote accounts about the demolition of the Breaker including its historical and mnemonic relevance, the cultural politics surrounding it, and the ethical dimensions of its extraction from the landscape by a mining company engaged in strip-mining on the surrounding land. These connections and dislocations between situated pasts show affective intensities arising suddenly even though dominant or more official narratives may have overwhelmed them. The sanitizing of the landscape of Saint Nicholas Breaker tries to empty the physical place of the material cultural traces of mining people/mined people to re-extract more coal through strip-mining operations, thereby rendering superfluous the underground miners’ labour by removing the last sign of it - the Breaker - from the landscape.

The Smart Grid using in the Kuzbass open-pit coalmine

The Smart Grid system become to apply all over the world. It provides significant efficiency increasing of power supply networks by supporting its balanced load. The key design features of each Smart Grid system depend on individual characteristics of particular power supply network which are determined by the structure of its electrical energy consumers. Relating to Kuzbass open-pit coalmines it is necessary to take into account the nonstationarity of its power supply scheme, the strict requirements of power supply reliability and the high capacity of consumers. This article is connected with the “Kedrovskiy” open-pit coalmine and describes its power supply scheme and the structure of its consumers. The downtimes and electrical equipment failures are analyzed and the connection between the number of emergency downtime and the number of working excavators is found out. The load of “Kedrovskiy” power distribution network is calculated for the strip mining operation. The results show power distribution network under consideration does not provide the effectiveness functioning and the implementation of Smart Grid is a good decision. There are the structure and design calculation of proposed Smart Grid in the article. It is finally depicted that Smart Grid” system decreases the downtimes of electric equipment and increases the power supply reliability.

Controlled Blasting in a Limestone Mine using Electronic Detonators: A Case Study

ABSTRACT Except for very deep-seated deposits, open cast mining method has been recognized as the safest and most productive mode for mining minerals. Ever growing demand in minerals and coal has compelled the mine operators to increase the size of mine, which has resulted in an increasing trend towards large capacity open cast projects. Explosives and blasting techniques play a significant role in efficient opencast mining operations. There have been constant technological developments towards safer, faster, economical and more efficient blasting systems. Further, globally increased competitiveness has necessitated to carryout blasts in such a way that the desired degree of fragmentation is achieved in the primary blast, with minimum undesired side effects such as ground vibration, air blast/noise, flyrock, generation of oversize boulders, formation of toe, and over break or back break. Hence, the ultimate objective of the blasting engineer is to ensure that the blasts are carried out in an eco-friendly manner. This paper presents a case study of limestone mine where a controlled blasting was conducted near a green structure of wagon tippler (at 2 m) being constructed for foundation work of belt conveyor as the mine management wants to double the existing production. This paper deals with controlled blast design and its implementation using electronic detonators with signature hole technique.