Open Pit Mining Operations Research Articles

Applications of 3D Reconstruction in Virtual Reality-Based Teleoperation: A Review in the Mining Industry

Although multiview platforms have enhanced work efficiency in mining teleoperation systems, they also induce “cognitive tunneling” and depth-detection issues for operators. These issues inadvertently focus their attention on a restricted central view. Fully immersive virtual reality (VR) has recently attracted the attention of specialists in the mining industry to address these issues. Nevertheless, developing VR teleoperation systems remains a formidable challenge, particularly in achieving a realistic 3D model of the environment. This study investigates the existing gap in fully immersive teleoperation systems within the mining industry, aiming to identify the most optimal methods for their development and ensure operator’s safety. To achieve this purpose, a literature search is employed to identify and extract information from the most relevant sources. The most advanced teleoperation systems are examined by focusing on their visualization types. Then, various 3D reconstruction techniques applicable to mining VR teleoperation are investigated, and their data acquisition methods, sensor technologies, and algorithms are analyzed. Ultimately, the study discusses challenges associated with 3D reconstruction techniques for mining teleoperation. The findings demonstrated that the real-time 3D reconstruction of underground mining environments primarily involves depth-based techniques. In contrast, point cloud generation techniques can mostly be employed for 3D reconstruction in open-pit mining operations.

Evaluation of buoyant action of groundwater and surface water interaction on pit slope stability using hydrogeological-stratigraphic-structural assessment within the Kawere catchment of the Nsuta mine

ABSTRACT In open-pit mining operations where activities are conducted below water table or close to surface water bodies, the mine is potentially faced with dewatering and slope stability challenges. Appropriate evaluation of slope stability to obtain adequate slope safety factor has continuously been the centre of geotechnical research locally and internationally. This paper evaluates the influence of buoyant action propagated by groundwater and surface (GW-SW) interaction on pit slope designed in multi-layered fractured rock with complex hydrology using Hydrogeological-Stratigraphic-Structural Assessment (HSSA) at the Nsuta Manganese Mine in Ghana. LEM analyses of the Pit C-western slope estimated an overall factor of safety (FOS) of 1.1, probabilities of failure (POF) of 7.5% and the reliability index (RI) of 1.4 in the slope stress field. However, when the groundwater was introduced, the slope FOS was reduced to 0.13, POF of 100.0% and (RI) of 0.00 indicating failure. FEM numerical model points to the location of maximum shear strain and total displacement in the argillite zone within the rock mass. The FEM seepage analysis model estimated groundwater pore pressure data along the critical slide surfaces from the crest of the slope to the bottom of the rock slope ranging between 250 kPa and 4250 kPa with an average pore pressure of 2250 kPa within the pit slope. This proposed HSSA approach used in the study provides innovative insights into the percentage failure contribution of the individual lithologies to the overall combined lithological susceptibility of the slope under stress and groundwater failure mechanisms, pointing out Ru ratio in pit slope stability estimation as inadequate.

Risk in Ultimate Pit Selection

The basis for the selection of the ultimate pit for an open pit mining operation is generally opaque. Some form of value-based analysis will generally guide the final decision; however, the value will often gradually plateau whilst the ultimate pit size continues to increase. There is no established framework to guide specialists in the selection of the ultimate pit, with such decisions regularly made on a somewhat arbitrary basis. The key component that is missing from the analyses typically used to select the size of the ultimate pit is risk. Once risk is quantified within the analysis framework, the decision-making range is significantly reduced, and the process for selecting the ultimate pit becomes more consistent, replicable, and defensible. This paper provides an approach to including risk in the process used to select the ultimate pit.

Spatio-temporal variations in dissolved trace elements in peat bog porewaters impacted by dust inputs from open-pit mining activities in the Athabasca Bituminous Sands (ABS) region

Considerable volumes of dust are generated from open-pit bitumen mining operations in northern Alberta, Canada. The reactive mineral phases of these dust particles can potentially dissolve in acidic (pH < 4) bog waters. Their dissolution could release trace elements (TEs), which could eventually alter these bog ecosystems. The impact of dust dissolution on the abundance of TEs in the dissolved (<0.45 μm) fraction of porewaters from excavated pits (30–40 cm deep) in the ombrogenic zone of five peatlands was evaluated. Porewaters were collected from four bogs situated within 70 km of mines and upgraders in the Athabasca Bituminous Sands (ABS) region, Alberta, Canada, and from a reference bog situated 264 km away. Over two consecutive years, the dissolved concentrations of some conservative (Al, Th, Y) and mobile lithophile elements (Fe, Li, Mn, Sr), as well as the metals enriched in bitumen (V, Ni, Mo), all increased with proximity to the mining area, in the ABS region. These trends reflect the observed increase in dust deposition with proximity to the mining area from independent studies of snow, lichens, and Sphagnum moss. Contrarily, the impact of dust dissolution on the concentration of potentially toxic TEs (As, Cd, Pb, Sb, and Tl) was negligible. Thus, the elements which are more abundant in the porewaters near industry are either ecologically benign (e.g. Li and Sr) or essential micronutrients (e.g. Fe, Mn, Ni, and Mo). Manganese was the only element which was enriched by more than 10x at all sites near the mining area, compared to its concentration at the reference site. The enrichments of all other elements were <10x, indicating that anthropogenic dust emissions from mining areas have had only a modest effect on the TEs abundance in peat porewaters.

Flyrock in surface mining Part II - Causes, sources, and mechanisms of rock projection

The fracturing and movement of rock that occurs in the vicinity of a stemmed borehole charge in open pit mining operations are described by examining the effects of the emitted stress waves - shock and elastic - and the expansion of high-pressure detonation product gases. Three principal modes of momentum transfer to fractured rock are identified, all linked to gas expansion work. This work can be delivered radially (burden), axially (stemming), and in the collar zone (cratering). Flyrock is generated under unusual combinations of blast parameters and rock properties. Although infrequent and seldom predictable, the generation of flyrock can nonetheless be interpreted and modelled in terms of the principal mechanisms of rock projection described in this study. The physical processes underlying these principal mechanisms are identified and will permit the development of predictive models for flyrock velocities.

Enhancing rock and soil hazard monitoring in open-pit mining operations through ultra-short-term wind speed prediction

Wind speed exacerbates challenges associated with rock stability, introducing factors such as heightened erosion and the possibility of particle loosening. This increased sensitivity to erosion can result in material displacement, thereby compromising the overall stability of rock layers within the open-pit mining site. Therefore, accurate wind speed predictions are crucial for understanding the impact on rock stability, ensuring the safety and efficiency of open-pit mining operations. While most existing studies on wind speed prediction primarily focus on making overall predictions from the entire wind speed sequence, with limited consideration for the stationarity characteristics of the sequence, This paper introduces a novel approach for effective monitoring and early warning of geotechnical hazards. Our proposed method involves dividing wind speed data into stationary and non-stationary segments using the sliding window average method within the threshold method, validated by the Augmented Dickey-Fuller test. Subsequently, we use temporal convolutional networks (TCN) with dilated causal convolution and long short-term memory to predict the stationary segment of wind speed, effectively improving prediction accuracy for this segment. For the non-stationary segment, we implement complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) to reduce sequence complexity, followed by TCN with an attention mechanism (ATTENTION) to forecast wind speed one step ahead. Finally, we overlay the predictions of these two segments to obtain the final prediction. Our proposed model, tested with data from an open-pit mining area in western China, achieved promising results with an average absolute error of 0.14 knots, mean squared error of 0.05 knots2, and root mean squared error of 0.20 knots. These findings signify a significant advancement in the accuracy of short-term wind speed prediction. This advancement not only enables the rapid assessment and proactive response to imminent risks but also contributes to geotechnical hazard monitoring in open-pit mining operations.

An integrated approach to safety in the design and operation of open-pit mining facilities

The article presents a pioneering integrated approach to assessing compliance with environmental, fire, industrial safety, and labor protection requirements in open-pit mining operations. The study was conducted at two existing open-pit mining facilities located in the Trans-Baikal Territory of the Russian Federation, analyzing the causes of injuries, statistical data, and comparing the mining technologies used. The key findings emphasize that the efficiency of deposit development and the safety of mining operations are heavily dependent on the quality of the technical design. The article also discusses software systems used for the design of mining facilities, which enable monitoring of the safety and labor protection aspects during quarry operation. The results of the comparative analysis are expected to be of interest to both quarry design specialists and the engineering and technical personnel of existing open-pit mining facilities. This integrated approach represents a significant advancement in the field, providing a comprehensive framework for enhancing safety and operational efficiency in the mining industry.

Использование термохимических технологий для отработки оставленных запасов угля

Introduction. Currently, despite the intensive development of high-performance mining equipment, significant coal reserves remain in the subsurface, which are impractical to extract using existing technologies and methods of mining them. At the same time, underground and especially open-pit mining operations are significantly inferior to the technologies of thermochemical mining of reserves in their place of occurrence due to the combined influence of negative factors (dust and gas emissions, seismic effects, etc.) at all stages of extraction, transportation and processing. The purpose of the research. Assessment of the possibilities of using thermochemical technologies to involve coal reserves left in the subsurface for mining geological and mining engineering factors in the field of industrial production. Methodology. To substantiate the choice of promising areas for the development of technical solutions for the integrated use and energy-efficient development of unprofitable coal reserves using traditional technologies, an analysis of factors that reduce their effectiveness and negatively affect the environmental situation in coal-mining regions was carried out. Within the framework of this analysis, the possibilities of mining reserves using alternative technologies are considered. For these purposes, an assessment of the effectiveness of thermochemical technologies (underground gasification of coal seams (UCG) and underground combustion (UCC)), tested in a wide range of mining and geological conditions and acceptable for processing thermal coal, was carried out. Results and discussions. An analysis of research in the field of UCG technologies has shown that, depending on the quality and composition of the blast, the heat of combustion of gasification products can vary widely, providing the required parameters. At the same time, the quality of coals significantly affects the efficiency of the technology, so during the gasification of hard and brown coals, the heat of combustion of gas differs by an average of 20%. Along with the significant positive factors of the UCG technology, it should be noted the high requirements for the tightness of the underground gas generator and the entire aerodynamic network and the loss of coal in the safety pillars and in the area of the gas generator. The elimination of these shortcomings is ensured by the consistent application of the UCC technology - the proposed combined technology of phased mining of prepared reserves, effective at depths up to 300 m. One of the most promising areas of implementation of such technology is distributed (small) energy. Conclusion. Traditional technologies of open-pit and underground mining of coal deposits require human participation in the implementation of basic technological processes. The development of the field’s reserves is accompanied by a number of concomitant negative environmental factors, one of the most significant is gas and dust emission during drilling and blasting operations. An alternative way of mining coal deposits is the use of thermochemical methods for mining coal reserves at the place of its occurrence, but their implementation in conditions of large-scale energy consumption is limited by the presence of large enterprises of a similar profile in the immediate vicinity. There is a steady positive trend in the development of small (distributed) energy in Russia. The proposed combined technology, which reduces environmental harm, can be used for mining deposits with limited reserves and in difficult mining and geological conditions and used for these purposes. Resume. 1. The article presents the results of research on the possibilities of using thermochemical technologies to increase the efficiency of extracting coal reserves. 2. It has been established that coal mining in modern conditions is accompanied by significant losses of reserves in the subsurface due to the requirements for the manufacturability of reserves when using high-performance equipment. The advantages of shaft-free thermochemical methods of mining coal seams are determined and the relevance of developing technical solutions for their practical implementation is substantiated. It is shown that the use of these technologies leads not only to an increase in the efficiency and completeness of coal reserves extraction, but also to a reduction in the environmental burden on the environment by eliminating blasting operations, as well as technological procedures related to the transportation and preparation of coal for use. A basic technological scheme for mining coal reserves based on the joint use of underground gasification and underground combustion technologies is presented. 3. The results of the research may be useful for assessing the possibilities of creating distributed energy facilities involving, among other things, coal reserves left behind as a result of mining with traditional technologies, especially in remote decentralized areas.

Assessing the Rainfall Implications on Surface Coal Mining Operations: Thar Case Study

Rainfall directly impacts the open-pit surface mining operations in the Thar Coalfield, Pakistan. The overall lithology hosting the lignite type of coal seams in the study area includes Dune Sand, alluvium, and soft sedimentary rocks. Due to the presence of three primary aquifers, the strata overlying and underlying the coal seams are under substantial porewater pressure. Additionally, heavy rainfalls in the Thar area lead to the accumulation of water in mines and may cause pit flooding, making it impossible to continue mining activities until the water is pumped out. Pit flooding often results in equipment damage and production delays. The main focus of the study is to investigate the impacts of heavy rainfall on the mining activities at Thar Coalfield. Two major aspects of open pit mining are considered in this study, i.e., production, and dewatering systems. Due to heavy rainfall, a significant production deviation (V) was noticed in comparison to regular months. The quantity of water drained from the pit (Qa) and anticipated inflow quantity (Qt) values were compared for the rainy season and other times. It was observed that heavy rainfall increases the production deviation from the planned targets and also increases the pit dewatering cost. Moreover, this study suggests preventive measures to address potential losses arising from intense rainfall.

THREE-DIMENSIONAL BROWNFIELDS: THE TRAGEDY OF THE MINING COMMUNITIES

The processes of active restructuring in the mining industry of many countries have entailed the physical closure of enterprises, accompanied by measures to mitigate their environmental and social impacts. Brownfields that emerged in districts with developed mining industries are predominantly perceived through a stereotypically flat, superficial, and narrowly literal lens. Adhering to such an approach is risky both in terms of ecology and in the aspect of economic losses incurred in territories with concentrated localization of mines. The article provides substantiation for the importance of perceiving brownfields within a threedimensional space, with due consideration given to geological deformations, dynamics of underground water and gas flows, and the potential of gravitational and geo-thermal energy. The authors propose interpreting brownfields as either oper ating or abandoned industrial sites with buildings and infrastructure facilities on the ground surface, as well as natural landscapes that are negatively affected by geological, hydrodynamic, and gas-dynamic processes characteristic of the disturbance of the subsoil due to underground or open-pit mining operations. The reuse and recycling of industrial waste accumulated within brownfields alone cannot ensure the survival of coal-mining towns. Similarly, depopulation cannot be halted solely through economic instruments. Thus, the strategy for the development of coal-mining towns should entail ‘enlightened’ restructuring in line with the ideas of ‘Smart Shrinking’.

A heuristic method for production scheduling of an open pit mining operation

ABSTRACT A mathematical model for production scheduling of open pit mines maximises the net present value and satisfies the reserves, pit slope angle, and production capacity constraints. A solution to this model aims to deliver an extraction sequence and the movement of materials across various stages within the operation over a defined planning horizon. However, given that the mineral reserves delineated into thousands of mining blocks form the geological input, the model falls in the category of large-scale optimisation problems, i.e. it is computationally intractable, and exact methods cannot solve realistic scenarios of the problem. Therefore, this paper contributes an alternative to the conventional mathematical model along with a corresponding heuristic method to solve this proposed model. An implementation of the proposed method at various realistic instances reveals better performance in terms of net present value, computation time and optimality gap as compared to the traditional methods.

Open slope stability of laterite nickel ore in Morowali utara

Unstable slopes are very dangerous for mining activities because if this phenomenon occurs it will have an impact on the mining activities; therefore, a slope stability analysis is needed because slope stability is a vital factor in the planning and operation of open pit mines. The purpose of this study was to analyze the characteristics of nickel, determine the factor of safety value and slope deformation, and determine the design of safe slope geometry in an open pit mine in Morowali Regency. The method used in this research is survey research by taking samples to be analyzed using the Bishop method with the Geostudio application, and the deformation of the data is analyzed using the Element method with the Plaxis application. The results of the analysis show that the Safety Factor (SF) on Slope 2 tends to be unstable when there is no load, with a deformation value of 0.945 cm, even after being loaded with heavy equipment and an earthquake, the stability value on the slope decreases. While Slope 1 and Slope 3 are still in a stable condition when loaded with heavy equipment when given additional earthquake loads, the SF on both slopes becomes unstable

A new model for the economic impact assessment of large-scale and deep open-pit mines

ABSTRACT This study focuses on examining economic impacts associated with deep and large-scale open-pit mining operations, which are often neglected in environmental impact assessments. Using Z-Fuzzy Delphi AHP and scenario-based techniques, 28 economic impacts were classified into seven categories and evaluated for the Sungun Copper mine in northwest Iran. Results indicated that socioeconomic factors had the highest weight (21.4%), while monetary factors had the lowest weight (7.5%). The economic sustainability score for the SCM was calculated to be 2.111, indicating poor economic performance. This research highlights the importance of considering economic impacts in mining operations for sustainable development.

Enhancing predictions of blast-induced ground vibration in open-pit mines: Comparing swarm-based optimization algorithms to optimize self-organizing neural networks

The objective of this paper is to present a method for predicting blast-induced ground vibration in open-pit mines that is based on the use of self-organizing neural networks (SONIA) and metaheuristic algorithms. In order to improve the accuracy of the SONIA model, several metaheuristic algorithms were employed, including the Manta Ray Foraging Optimization (MRFO), Hunger Games Search (HGS), Aquila Optimization (AO), and Naked Mole-Rat Algorithm (NMRA). Additionally, the k-fold cross-validation technique was used to identify the best parameters for the algorithms, which were then used to retrain the models for predicting blast-induced ground vibration. The effectiveness of the proposed method was evaluated using a case study of an open-pit coal mine in Vietnam, which had 288 blasting events. The study found that SONIA was a suitable neural network for predicting blast-induced ground vibration due to its self-organizing structure, even with a small dataset containing complex relationships. However, the SONIA model could be further optimized using the metaheuristic algorithms to improve its accuracy. The study found that the MRFO-SONIA model was the most reliable and accurate, with the lowest error (MAE = 0.379, RMSE = 0.453, MAPE = 0.08) and the highest reliability (R2 = 0.896). Meanwhile, the HGS-SONIA, AO-SONIA, and NMRA-SONIA models provided lower performance, with MAE values of 0.455, 0.500, and 0.492, RMSE values of 0.552, 0.603, and 0.580, MAPE values of 0.100, 0.112, and 0.111, and R2 values of 0.845, 0.815, and 0.829, respectively. The results of this study demonstrated the potential of using metaheuristic-based SONIA models to enhance predictions of blast-induced ground vibration in open-pit mines. This approach could prove useful in other operations in open-pit mines where there is a need to predict vibrations or other disturbances/negative effects resulting from specific mining activities.

Application of Soft Computing, Statistical and Multi-Criteria Decision-Making Methods to Develop a Predictive Equation for Prediction of Flyrock Distance in Open-Pit Mining

Blasting operations in open-pit mines generally have various management strategies relating to flyrock. There are empirical models for calculating the flyrock distance, but due to the complexity and uncertainty of rock properties and their interactions with blasting properties, there are still no models that can predict the flyrock distance that may be applicable across mining operations in general. In this regard, the Jajarm bauxite mine complex was used as a case study. The purpose of this study was to develop and evaluate different methods that can predict flyrock distance. For this purpose, soft computing models were developed using generalized regression neural network (GRNN), gene expression programming (GEP) and genetic-algorithm-based GRNN (GA-GRNN) methods. To obtain statistical models, multivariable regression was applied in the form of linear and nonlinear equations. A flyrock index was introduced using a classification system developed by incorporating fuzzy decision-making trial and evaluation methods (fuzzy DEMATEL). In order to achieve this goal, the data of 118 blasts in eight mines of the Jajarm bauxite complex were collected and used. Following this, four performance benchmarks were applied: the coefficient of determination (R2), variance accounted for (VAF), root-mean-square error (RMSE) and mean absolute percentage error (MAPE). The performance of the models was evaluated, and they were compared with each other as well as with the most common previous empirical models. The obtained results indicate that the GA-GRNN model has a higher performance in predicting the flyrock distance in actual cases compared to the other models. At first, data on factors that were the main cause of flyrock (and had a direct impact on it) were collected and classified from different blasts. Then, using the collected data, 19 different combinations were established, which can be used to provide the appropriate predictive equation. The purpose of this work is to more accurately predict flyrock and prevent heavy damage to buildings and mining machines across the mining complex.

WALL CONTROL AND BLAST PATTERN ANALYSIS USING BLAST VISION® TECHNOLOGY

Wall control and blasting are two major activities that significantly impact the productivity and safety of open-pit mining operations. Although many monitoring equipment are used for improving slope stability, there is still a need for understanding slope behaviour during a blast. This paper describes a new technology called Blast Vision®, developed by Ground Probe, for monitoring the interaction between blasting and slope stability with a temporal resolution in the range of milliseconds. This technology represents an innovative departure from standard blast vibration sensors by measuring ground luminance changes on the ground surface through drone-based computer vision. Blast Vision application for slope stability, misfires and fly rocks is investigated in this publication.

An optimization model for the real-time truck dispatching problem in open-pit mining operations

An optimization model for the real-time truck dispatching problem in open-pit mining operations

Modeling Productivity Reduction and Fuel Consumption in Open-Pit Mining Trucks by Considering the Temporary Deterioration of Mining Roads through Discrete-Event Simulation

Open pit mining is based on dynamic operations within the open pit, with the haulage operation being the most decisive in terms of the cost and the overall productivity of the operation. A vital aspect for the success of the haulage operation are the conditions of the roads, which change over time due to wear and tear. The present work aims to model and to evaluate the effect of temporal deterioration affecting mining roads in an open pit mining operation through rolling resistance, using the discrete event simulation (SED) tool to evaluate two key aspects of the operation: productivity and fuel consumption. Additionally, to reverse road deterioration, the assignment of a grader with a variable frequency of use will be modeled through a parallel model. The case study is a 5 km road with a slope of 9.5%, a fleet of 10 trucks, and their capacities of 300 tons, loaded in a 24 h simulation model. The results show that not considering road deterioration can mean an overestimation of productivity of up to 600 Ton/hr, and an overconsumption of 78%. The application of a motor grader could decrease the negative effects of roads deterioration, which depends on the frequency of its assignment. The results show that for the rate of productivity and fuel consumption for every hour of frequency that the motor grader does not do road maintenance, the production loss is 600 tons, and the fuel consumption increases by approximately 1800 L in a day.

Kajian hidrologi dan hidrogeologi daerah penambangan, studi kasus lipatan sinklin di Sungai Mahakam, Kutai Kartanegara , Provinsi Kalimantan Timur

Changes in land use due to open pit mining operations, indirectly affect the hydrological cycle. Open pit mining operations, especially the open pit method, greatly affect subsurface conditions, such as lithology and hydrogeology. The purpose of this study was to analyze the hydrological and hydrogeological conditions before mining on syncline folds in the Mahakam river. This research is an inductive research with an analytical approach which includes the study of land use, hydrological conditions, geology, and hydrogeology. The land use of the research area is dominated by plantations (84%) with a rain catchment area of ​​995.9 hectares. The results of the hydrological analysis yielded daily rainfall values ​​with a 5-year recurrence of 208.4 mm, annual rainfall of 2.177.32 mm, runoff 238.63 mm/yr, evapotranspiration 1,031.16 mm/yr and groundwater recharge 907.53 mm/th. The lithology of the study area is dominated by sandstone and clayey siltstone. The results of the aquifer test (pumping test) showed that the average K value (hydraulic conductivity) of sandstone was 1.33 × 10-2 m/s and claystone was 6.77 × 10-10 m/s. The results of the hydrogeological analysis show that the top layer is an aquitard, below it is an aquifer, then an aquitard, and the bottom is an aquiclude. The type of aquifer in the study area is classified as semi confined aquifer

A nested multiple-objective optimization algorithm for managing production fleets in surface mines

The fleet management system (FMS) plays a vital role in truck and shovel open-pit mining operations. The list of expectations from the FMS ranges from data recording to making operational decisions. This article proposes a nested fleet management system (N-FMS) for open-pit mining operations. The primary contribution of the proposed FMS is connecting the operation to the strategic plan by incorporating shovel allocation and plant feed optimization. Another contribution of the proposed N-FMS is that it simultaneously optimizes the utilization of the shovel fleet and truck fleet. The proposed FMS makes decisions using two nested multiple-objective mixed-integer linear goal programming models. Results of the implementation of the developed N-FMS in a metal mining case study show that compared to a locked-in operation, the mine experienced a 14.6% improvement in its required truck fleet capacity to meet the production target.