Open Pit Research Articles

Research on the Applicability of Integrated Earth Lifting Machine for 500KV Transmission and Substation Project in Highland Area

In the power construction project, the tower foundation deep pit operation is a fundamental and important process, because of its operation point of the geological foundation structure complex and changeable, large amount of work, many dangerous factors and difficult to observe and identify, the construction is easy to cause safety accidents. State Grid Gansu Power Company has developed a set of intelligent equipment for deep foundation pit operation which is easy to operate, safe, reliable and complete in function, relying on the equipment to actively and timely discover the danger and early warning, and automatically take effective measures to strengthen the protection of personnel, crack the problem of safe operation of deep foundation pit and prevent the occurrence of infrastructure safety accidents. Since this project is located in the plateau area of Tibet, it is intended to study the applicability of the integrated deep foundation pit operation intelligent machine in the plateau area through this project. This project adopts "integrated deep pit operation intelligent machine"; this equipment is specially designed for a series of problems encountered in deep pits and other limited spaces, it integrates a number of practical functions: electric lifting, real-time gas detection, intelligent air supply, automatic sound and light alarm, emergency rescue, differential hanging point, soft ladder hanging point, lighting power, etc. It aims to protect the lives of construction personnel, improve the safety and reliability of construction, enhance construction efficiency, and is a kind of equipment with convenient transportation, installation and operation, diversified and integrated functions and intelligent control.

Analisis Produktivitas Alat Angkut dan Muat Pada Pengupasan Overburden di PT. XYZ Desa Batuah, Kutai Kartanegara, Kalimantan Timur

PT. XYZ is a company engaged in coal mining contractors located in East Kalimantan. During mining activities, PT. XYZ uses an open-pit mining system. In February 2023 PT. XYZ had a production target overburden of 193,700 bcm, but in reality, the production target only reached 119,529 bcm.. The productivity of the conveyance and loading equipment is by field conditions to be compared with the company's production achievement targets. The research method used is a quantitative method where this research takes data directly and interviews in the field. The results of the calculation analysis, the production of means of conveyance dumptruckIVECO 350 reached 27.17 Bcm/hour, dump truck ISUZU GIGA FV285 reached 22.16 Bcm/hour, andarticulated dump truck VOLVO A40G achieved 54.57 Bcm/hr. Production of the Sanny SY330H excavator truck reached 178.63 Bcm/hour and the XCMG X370CA excavator reached 154.09 Bcm/hour. The amount of production of the actual means of conveyance that was achieved was 193,700 Bcm/hour. The parameters that affect the amount of production of a tool both hauling and loading, namely circulation time, tub or bucket capacity, amount of filling, fill factor, and material expansion factor. However, based on field observations by the author, there are several additional factors such as the type of weather factor and the condition of the mine road or ramp. In addition to the weather factor, road conditions that are far from the existing standard size will affect the amount of production of a tool.
 Keywords: coal, Overburden, Production, productivity

Influence of soil anisotropic stiffness on the deformation induced by an open pit excavation

Influence of soil anisotropic stiffness on the deformation induced by an open pit excavation

Комплексный анализ результатов мониторинга устойчивости уступов карьера с использованием геофизических методов исследования

The Response to challenges related to safety in open-pit mining of mineral deposits is based on continuous monitoring of the pit wall stability as a whole as well as the stability of problematic areas of the pit wall and individual benches. Control of the geomechanical state of the adjacent rock mass using local geophysical methods plays an important role in the overall monitoring of stability of the open-pit elements. The control allows studying in more detail the state of benches and groups of benches in critical areas of the open-pit and developing measures to ensure production safety on this basis. One of the main interdependent factors affecting the pit wall stability is, on the one hand, the size of the disturbed zone that depends on both natural and mining-induced rock fracturing; on the other hand, the level of ground water changing over time depending on the season. The importance of joint account of the factors above has stipulated to propose a comprehensive methodical approach to study water saturation and structural disturbance of rocks in the wall of a deep open-pit. The method consists in periodic, seasonally synchronized, geophysical studies using seismic profiling and GPR sounding and allows identifying the areas of high water saturation and disturbance in the adjacent rock mass. The methodological approach makes it possible to estimate the effect of the main time-varying impact factors (water saturation, natural and mining-induced disturbance, anomalies of physical properties of the rock mass) on the slope stability and provides a scientific and technical basis for developing engineering measures to improve the safety of deep open-pit mining.

Leachate Experiments to Evaluate Weathering of Waste Rock for Backfill Aquifers in Restored Coal Mine Pits, Powder River Basin, USA

Restoration of open-pit mines may utilize waste rock for landscape reconstruction, which can include the construction of backfill aquifers. Weathering and contaminant transport may be different in backfill aquifers compared to the surrounding aquifer because of newly available mineral surfaces and transportable nano- to micro-scale particles generated during mining. Waste rock from the Cordero Rojo open-pit coal mine in the Powder River Basin was exposed to benchtop leachate experiments for 20 weeks at temperatures of 5 °C and 20 °C. Collected leachate was analyzed for Eh, pH, specific conductance, alkalinity, and cation and anion concentrations as unfiltered and 0.45-μm and 0.2-μm filtered concentrations. During the experiment, leachate Eh and pH substantially varied during the first 55 days, which corresponds to a period of high specific conductance (>1000 µS/cm) and alkalinity (>200 mg/L). Correspondingly, anion and cation concentrations were the largest during this early weathering stage, and the filter fractions indicated multiple forms of transported elements. After this early weathering stage, column leachate evolved towards a weathering equilibrium of neutral, oxidizing, and low solute conditions indicated by positive Eh values, pH near 7, and specific conductance <500 μS/cm. This evolution was reflected in the decline and stabilization or non-detection of metal(loid) concentrations reflective of a shift to primarily bulk aluminosilicate weathering when coal- and salt-associated elements, such as arsenic, cadmium, and selenium, were not detected or at minimal concentrations. Over the course of the experiment, the solute trend of certain elements indicated particular weathering processes—cadmium and nanoparticle transport, selenium and salt dissolution, and arsenic and pyrite oxidation. The mining of overburden formations and use of the waste rock for backfill aquifers as part of landscape reconstruction will create newly available mineral surfaces and nanoparticles that will weather to produce solute concentrations not typically found in groundwater associated with the original overburden.

Metal-free sampling methods for dust, rainwater, surface water, plants, and sediments: A selection of unique tools from the SWAMP laboratory

Contamination control remains one of the greatest challenges for the reliable determination of many trace elements in environmental samples. Here we describe a series of metal-free sampling devices and tools designed and constructed specifically to minimize the risk of contamination by trace elements during sampling of dust, rainwater, surface water, plants, and sediments. Plastic components fabricated using 3-D printing include polylactic acid (PLA), polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), polypropylene (PP), polycarbonate (PC) and PC with carbon fibre. When additional strength is needed (e.g. supporting structural components), carbon fibre, aluminum (Al), or 316 stainless steel (SS) is used. Other plastics employed include acrylic and vinyl. Epoxy glue or SS may be used for joining components, but do not come into contact with the samples. Ceramic (zirconium dioxide) cutting blades are used where needed. Each plastic material was evaluated for contaminant trace elements by leaching with high purity nitric acid in the metal-free, ultraclean SWAMP laboratory. The devices were tested in the field to evaluate their performance and durability. When combined with appropriate cleaning procedures, the equipment enables ultraclean collection for trace element analysis of environmental media.•Plastic sampling devices were designed and constructed using 3D printing of PLA, PET, PETG or PP.•Leaching characteristics of plastic components were evaluated using high purity nitric acid in a metal-free, ultraclean laboratory.•Each sampling device was successfully field-tested in industrial settings (near open pit bitumen mines and upgraders), and in remote locations of northern Alberta, Canada.

Численное моделирование процессов естественного проветривания карьера при вариации его глубины в условиях инверсионного состояния атмосферы

The research objective is to assess the influence of the background stratification parameter and the depth of an open pit mine on the time of natural ventilation of the mine and the level of atmospheric pollution at the upper side of the pit downwind of blasting operations in conditions of the North. An aerothermodynamic model of the atmosphere was used, in which the equations of dynamics in the approximation of incompressible fluid were supplemented with the heat transfer equation, and the buoyancy and background stratification mechanisms were taken into account. The model was created in a general-purpose COMSOL software package and makes it possible to study aerothermogasodynamics of the atmosphere in its various states. A two-dimensional CFD-model of the open pit atmosphere was tested using the recirculation ventilation process. The background stratification parameter (from 0.0 to +0.025 °С/m with the increment of 0.005 °С/m) and the quarry depth from 300 to 700 m were variated. The wind velocity of 1 m/s at the upper side of the pit, the initial location of the dust and gas cloud (in the center of the pit near its floor) and the slope angle of the pit wall of 45° were recorded. A significant increase in the time of natural ventilation of the open pit is demonstrated at intensifying inversion of the atmosphere. Two formation types of the maximum pollution area with the increasing pit depth are predicted: (1) displacement from the center to the lee side of the pit at neutral stratification; and (2) position in the center of the pit near its floor at positive background stratification. It is shown that increasing of both the pit depth and the background stratification parameter leads to a noticeable increase in the time to reach the maximum concentration at the upper side of the pit and a decrease in the value of this maximum. For the recirculation ventilation scheme, intensification of inversion in the atmosphere increases the time of natural ventilation, but reduces the level of atmospheric contamination at the upper side of the pit downstream.

Оценка трещиноватости отрабатываемого горного массива на основе аэрофотосъемки и методов машинного зрения

The task to assess rock mass jointing are currently usually solved in manual mode, which requires high qualification of the specialists and considerable time expenditures. Automation of such tasks is important in terms of reducing the time of image processing and obtaining additional information on the geomechanical state of the rock mass. The article discusses the possibilities of using computer vision and artificial intelligence technologies to assess jointing of the rock mass. For this purpose, aerial photography data obtained using unmanned aerial vehicles are used. The images are processed with the software developed by the authors, which performs tracing of the joints based on a neural network of a dedicated architecture. The results of processing aerial photography data are presented using the cases of coal strip mines in Kuzbass and open-pit mines of the Kola Peninsula. The use of neural network in processing of the aerial survey data of the rock masses has shown the promising potential of the method. After processing the data of tracing the jointing fields, it becomes possible to monitor the behavior of the rock mass by using the visualization tools for additional fields of characteristics, which allow to assess the nature of changes occurring under anthropogenic loads. The developed algorithms make it possible to significantly accelerate the processes of aerial survey data processing to assess the structural disturbance of the rock mass.

Инструмент оптимизации выемочных единиц на открытых горных работах для блочных моделей месторождений

The MINEFRAME mining and geological information system features an algorithm and a software module to create bench-wise mining units for surface mining operations, which optimizes losses and dilution with due account for the spatial variability of the ore and gangue rock composition. The software module is based on both wireframe and pure block models, and takes into account a given development direction. The algorithm defines the mineable reserves of the deposit as a set of mining unit models. The module determines the expected levels of rational loss and dilution for each mining units of the bench, for each ore body, for the bench and for the open pit in general. The mining units also become the reference points for the design of blasting operations and the basis for the development of special measures to modify the parameters of the mining system locally. The obtained mineable reserves can be used in defining the pit boundaries and planning mining operations, and the contours of mining units will guide the design of the blast blocks. The algorithm can also be used to clarify the pit boundaries in the footwall of a sloping deposit and for economic comparison of the development options.

Прогнозная оценка устойчивости борта карьера в тектонически напряженном массиве

The article presents an approach to determining the stability of the pit walls and benches using a set of methods. The results of numerical modeling of the stress-and-strain state are presented for the rock mass in vicinities of one of the quarries in the Khibiny Apatite Arc. Calculations were made using elastic approach to a three-dimensional finite-element model which incorporates basic geological, mining engineering and geomechanical data. The impact of gravitational and tectonic stress field is demonstrated on the stability of the pit wall and benches during its development. Potentially unstable areas have been determined in the wall and benches of the open pit design contour. The identified features of the stress-and-strain state of the rock mass in vicinities of the pit wall make it possible to increase the justification level of technical solutions for the development of surface mining operations and to design preventive measures that would ensure the stability of structural elements of the open pit.

Effects of microtopography shaping on characteristics of eroded sediment particles of a dump slope in an opencast coal mine in China

AbstractThe properties of sediment particles are crucial research areas for understanding soil erosion on dump slopes. In this study, the slope of the southern dump of the ATB opencast coal mine in the Pingshuo mining area in Shanxi Province, China, was selected to conduct microtopographical shaping and artificial rainfall simulation experiments. Three different gradients of rainfall intensity, 20, 50, and 80 mm·h−1, were set. The main component of rainwater was water (chemistry H2O) by a rainfall duration of 30 min. A Microtrac S3500 laser particle size analyzer was used to measure the collected erosion sediment particles. This study conducted level benches and fish‐scale pits microtopography shaping on the slope of the waste dump. The dimensions of the level bench design were 1, 2, and 1 m for the step width, for the step length, and between each level bench, respectively. The fish‐scale pits were 60 cm (length), 40 cm (width), and 30 cm (depth). The horizontal and row spacing of each fish‐scale pit was 1 m, and an unshaped terrain was used as the control group. Through dynamic monitoring and statistical analysis of the data, the impacts of rainfall intensity and microtopography shaping mode on the features of the eroded sediment particles were analyzed. Fine silt particles (53%) were lost as a result of the surface erosion of the slope. The mean starting periods of sediment particle loss decreased with the increase in rainfall intensity (589 s > 402 s > 305 s). Additionally, the clay and silt particle enrichment ratios decreased (ER >1), whereas the sand particle enrichment ratios increased (ER <1). The level benches had a stronger interception effect on fine sediment, whereas the fish‐scale pits had a weaker interception effect on sediment particles under heavy rain. The distribution properties of erosion sediment particles on a slope can be assessed using fractal dimension as an index. This study is significant for understanding the erosion mechanism of eroded sediment particles on dump slopes and provides a scientific foundation for soil erosion control on opencast coal mine dump slopes in the Loess Plateau. These results highlight the potential for the level bench to effectively delay the occurrence of runoff and greatly enhance the interception of sediment particles.

Research on Energy Efficiency Characteristics of Mining Shovel Hoisting and Slewing System Driven by Hydraulic-Electric Hybrid System

Mining shovel is a crucial piece of equipment for high-efficiency production in open-pit mining and stands as one of the largest energy consumption sources in mining. However, substantial energy waste occurs during the descent of the hoisting system or the deceleration of the slewing platform. To reduce the energy loss, an innovative hydraulic-electric hybrid drive system is proposed, in which a hydraulic pump/motor connected with an accumulator is added to assist the electric motor to drive the hoisting system or slewing platform, recycling kinetic and potential energy. The utilization of the kinetic and potential energy reduces the energy loss and installed power of the mining shovel. Meanwhile, the reliability of the mining shovel pure electric drive system also can be increased. In this paper, the hydraulic-electric hybrid driving principle is introduced, a small-scale testbed is set up to verify the feasibility of the system, and a co-simulation model of the proposed system is established to clarify the system operation and energy characteristics. The test and simulation results show that, by adopting the proposed system, compared with the traditional purely electric driving system, the peak power and energy consumption of the hoisting electric motor are reduced by 36.7% and 29.7%, respectively. Similarly, the slewing electric motor experiences a significant decrease in peak power by 86.9% and a reduction in energy consumption by 59.4%. The proposed system expands the application area of the hydraulic electric hybrid drive system and provides a reference for its application in oversized and super heavy equipment.

A Grade Control Method without Sampling Preparation Based on Spectrometric Techniques and the Use of Electronic Detonators in an Open Pit Tungsten Deposit

A Grade Control Method without Sampling Preparation Based on Spectrometric Techniques and the Use of Electronic Detonators in an Open Pit Tungsten Deposit

The Role of Promotional Media in Developing Sustainable Mining Heritage Tourism

Open Pit Nam Salu tourist area, a Belitung National Geopark that has received recognition as a UNESCO Global Geopark, is one of the mining heritage-based tourist attractions visited by tourists from several countries from all continents of the world. For this reason, this research aims to analyze the role of promotion media in developing sustainable tourism on mining heritage. The method used in this research is descriptive qualitative using the Systematic Literature Review method, supported by interview and documentation methods. The study was conducted in Belitung, Bangka Belitung Province, Indonesia. The results show that promotional media is essential in helping the development of sustainable mining heritage tourism. The dominant promotional activities the Open Pit Nam Salu tourist attraction management carries out are advertising and digital/internet marketing. Then, regarding the sustainability of mining heritage tourism, at least three pillars must be met, starting from the environmental, social, and economic pillars.

Secondary Succession of Vegetation in the Former Coal Mine Area PT. Bukit Asam Tbk

Open-pit mining activities cause environmental degradation such as decreased soil fertility and degradation of plantation. After mining activities is completed, land improvements will be carried out through post-mining reclamation. Low pH conditions, high metal concentrations and low organic matter are the main problems in post-mining activities reclamation land. Reclamation activities carried out by PT. Bukit Asam, Tbk runs continuously from time to time. Mining land that is no longer used for mining activities must immediately carry out land reclamation activities to preserve the environment and maintain ecosystem stability in coal mining areas. The reclamation efforts that have been carried out require vegetation analysis to determine the vegetation growing on the reclaimed land of various ages. This research aims to analyze vegetation using the transect method in reclamation areas aged 1 year, 3 years, 5 years, and natural land as a control. The research results show that all reclaimed land is ultisol soil which is acidic (pH 3.52 – 4.50), and the older the reclaimed land can increase the C-Organic, C-Total and C/N of the soil. The condition of land that is 5 years old also has lower soil temperatures and greater humidity than land that is younger. The Importance Value Index (INP) of seedlings, saplings, poles and trees on reclaimed land at 1 year old is smaller than at 5 years old. The common vegetation found on all reclaimed land of different ages is seedlings (Mimosa pudica), saplings (Malaleuca cajuputi), poles and trees (Malaleuca cajuputi, Acacia mangium).

Exploring the potential of smartphone photogrammetry for field measurement of joint roughness

Rock joints play a crucial role in determining the behavior and stability of rock masses. Despite their importance, there is a lack of devices for easily and accurately measuring joint roughness in field conditions. This research explores the potential of smartphone photogrammetry as a solution for large-scale joint roughness mapping. A large natural rock joint from an open pit mine in Yunnan, China, served as the specimen. Both two dimensional (2D) and three dimensional (3D) roughness parameters were utilized to characterize joint roughness. The study found that the accuracy of smartphone photogrammetry is acceptable when operated with guidance. The measurement errors were 1.7%, 4.7%, 7.8%, and 6.1% for the Z1, Ai, Z2, and PSD-D roughness parameters, respectively. In conclusion, this study demonstrates that using smartphone photogrammetry as a portable and cost-effective method for measuring joint roughness in field conditions has the potential to significantly benefit engineering geological investigations.

A direct block scheduling model considering operational space requirement for strategic open-pit mine production planning

A direct block scheduling model considering operational space requirement for strategic open-pit mine production planning

An inventory of opencast mining excavations recultivated in the form of water reservoirs as an example of activities increasing the retention potential of the natural environment: a case study from Poland

The article presents examples of the employment of various geodetic measuring tools used for a detailed inventory of lake basins and shorelines. The measurement and analysis covered three post-mining open pit excavations recultivated as water reservoirs: two in Krakow (Bagry Wielkie and Bagry Małe) and one in Piaseczno (Piaseczno Sulphur Mine). Attention was paid to the factors that reduce the accuracy of the inventory of some flooded post-mining excavations, which determine the degree of usefulness of the morphometric data set for later analyses. According to available estimates, only about one-third of all water reservoirs in Poland have detailed geodetic documentation in the form of bathymetric maps. This documentation usually does not include water reservoirs of anthropogenic origin formed after the flooding of post-mining excavations (mines: sand, gravel, clay, limestone, sulphur, aggregates, etc.). The authors suggest the introduction of a document known as a reservoir documentation card and the creation of a database covering all anthropogenic water reservoirs. Considering the water deficit in Poland, it may be necessary to develop a detailed database of water resources in the short term.

SEISMICITY of the URALS and WESTERN SIBERIA in 2018–2019

The article summarizes information about seismic network in the Urals and Western Siberia region, describes processing technique, presents short analysis of seismic activity for 2018–2019. Seismic network capability is shown for whole territory under control. It was found that about 82 % of registered events are explosions in mines and open pits, 74 events are natural and 76 are induced ones. For the strongest induced events, variants of source parameters obtained by different agencies are shown.

TIME SERIES INSAR ANALYSIS FOR SLOPE STABILITY MONITORING USING SENTINEL-1 IN OPEN PIT MINING

Abstract. Surface mining is an important economic activity in many regions where mineral resources are located close to the surface. The process of ore extraction is characterised by high pit walls with steep slopes. The mining process introduces significant stress and strain changes that could lead to movement on the slope face. Slope failure on the pit walls can occur without warning and can lead to loss of life and disruptions to the mining process. The monitoring of slopes remains the most reliable way to detect movement on unstable slopes. Therefore, slope monitoring programmes have been established to monitor and measure slope movement to help mine management with the stability status of open pit slopes. Conventional monitoring techniques include visual inspections and in situ instrumentation that are point-based, time-consuming, and costly. Open-source remote sensing techniques such as Synthetic Aperture Radar interferometry have been used to monitor slope movements on open-pit mine walls. Time series interferometric Synthetic Aperture Radar (InSAR) can be used to overcome limitations of in-situ monitoring for monitoring slope movements in open-pit mines.