Open Pit Research Articles

Na krawędzi odkrywki. Praktyki postartystyczne i zaangażowanie klimatyczne na plenerach w Opolnie-Zdroju

The author analyzes the network of activist-artistic practices carried out as part of transdisciplinary gatherings in Opolno-Zdrój, located on the edge of the Turów open-pit coal mine, where the pioneering artistic ecological plein-air event Ziemia Zgorzelecka “Science and art in defense of the natural human environment” took place in 1971. The author describes these activities, conducted by the Office for Post-Artistic Services, using the theory of post-artistic practices and “usology,” and pointing out similarities and differences with related concepts of artivism, socially engaged art, or art with community. Borrowing concepts from the field of environmental humanities and written art theory in the context of the climate crisis, the author shows how those associated with the Office experiment with using art as a tool to enter into relationships and intervene in the reality of Opolno-Zdrój. The post-artistic practices carried out in Opolno-Zdrój are a successful exercise in “ecologizing” the methods and language of art, which allow for meaningful engagement with the issues of the planetary climate and environmental crisis, and provide a valuable tool for expanding imagination, useful speculation, and practical shaping of the future. Key-words: climate, ecology, post-art, post-artistic practices, extractivism, plein-air, Opolno-Zdrój, “Turów” mine

Design and Planning of Mine Drainage Systems at PT. Pertama Mina Sutra Perkasa, Puger District, Jember Regency, East Java, Indonesia

PT. Pertama Mina Sutra Perkasa, a limestone mining company, operates in Grenden Village, Puger District, Jember Regency, East Java Province. Utilizing an open mining system, the company faces challenges related to mine drainage. Based on rainfall analysis from 2013 to 2020. the planned rainfall rate is 25.938 mm/hour, with a rainfall intensity of 5.712 mm/hour, resulting in a runoff water discharge of 0.599 m³/second. The water discharge entering the well at the site is 2159.08 m³/hour. The designed drainage channel has a discharge capacity of 3.109 m³/second, a wet surface area of 0.5 m², a channel bottom slope of 0.03%, a hydraulic radius of 0.25 m, a Manning roughness coefficient of 0.011. a wet cross-section circumference of 2 m, and a flow depth of 0.5 m. The planned well dimensions are 60 m in length, 20 m in width, and 7 m in depth, with a volume of 8400 m³. The current sludge settling pond has three compartments with a total capacity of 393.75 m³. The proposed design for the sludge settling pond includes a length of 60.6 m, a width of 15 m, a depth of 7 m, and a volume of 5454 m³. The actual mud dredging frequency is once every 2 days, while the proposed plan extends this interval to 9 days using a Doosan 340DX type excavator. This comprehensive drainage system design aims to efficiently manage runoff and sedimentation, ensuring sustainable mining operations

MINE WATER MANAGEMENT IN THE COAL MINING PROCESS

The open mining method has the potential for the formation of mine water. Mine water is characterized by a high degree of acidity which affects the life of organisms and the quality of the environment indirectly or directly, therefore it needs to be managed. This study examines mine water management at PT Adaro Indonesia. The methods used in the research were field studies and laboratory experiments. Grab sampling is used to take water samples, with the test parameters being pH, Fe and Mn metals and total suspended solid (TSS). Data analysis was carried out quantitatively and descriptively. The mine water management used is in the form of a settling pond. The settling pond consists of several compartments, namely sedimentation pond, safety pond, treatment pond and mud pond. The quality of mine water management through a series of settling ponds obtained changes in pH to 6.07, Fe metal 0.0465 mg/l, Mn metal 1.3513, and TSS 35 mg/l with an efficiency of more than 50%. The quality of mine water produced after going through management has met the established regulations, namely Decree of the Minister of Environment and Forestry No. 1347/MENLHK/SETJEN/PLA.4/12/2022.

Mapping open-pit mining area in complex mining and mixed land cover zone using Landsat imagery

The monitoring of open-pit mining and reclamation activities is an important part of ecological protection across various countries. Among the many methods of monitoring open-pit mining areas, satellite remote sensing is the most widely used and effective. However, few works have been conducted to map open-pit mines over a larger geographical scale, or have considered complex land cover types, or a wide variety of mine properties. This work proposes a framework for mapping open-pit mines for areas over complex land cover and mining properties, including preprocessing, classification, and postprocessing steps. First, the pixels that did not contain mines were masked, second the mines were divided into two categories according to their spectral characteristics, then the selected samples and classified to obtain the classification results of mines, and third mis-classified pixels were removed. This work used Landsat images and Google Earth Engine to map the open-pit mines over Shanxi in 5-year steps from 2000 to 2020. The average producer and user accuracy of the results was found to be 79.4% and 83.2% respectively. The experimental results showed that open-pit mining areas in Shanxi first increased and subsequently decreased over the past twenty years. Additionally, the new preprocessing, classification, and postprocessing workflow was found to be effective, especially in environments with more vegetative cover.

Optimization of cycle time for loading and hauling trucks in open-pit mining

Purpose. The purpose of the paper is to provide open-pit mining operations with practical strategies and insights to optimize truck loading and hauling cycles, ultimately leading to enhanced productivity and economic advantages. Methods. The objectives are to minimize loading time, optimize the haul road network, enhance truck performance, and optimize dumping and return time. By diligently implementing these methods and achieving these objectives, open-pit mining operations can significantly reduce the truck cycle times, resulting in increased productivity, lower costs and improved profitability. Findings. In this case, the total loading time of the excavator and shovel is determined to be 3.98 and 2.92 minutes, respectively, while the hauling time for total loading of the open-pit floor depends mainly on the average distance and speed of 239 m and 10.1 km/hour, which results in 1.53 minutes. Originality. As a result, the total cycle time for open-pit mining is 19.765 minutes, resulting from the total loading time, hauling time for total loading, total dumping time, and total return time for empty transport of 4.265, 8.46, 0.86 and 6.18 minutes, respectively. Practical implications. By combining theoretical analysis with practical insights and site-specific considerations, the paper aims to provide a comprehensive and applicable framework for optimizing truck cycle time in open-pit mining, resulting in improved efficiency and profitability of mining operations.

Комплексная оценка геоэкологических рисков при ведении открытых и подземных горных работ

Introduction. Geo-ecological risk is the probability of adverse events leading to a violation of the stability of the existing ecological system or the natural and technical geo-system “rock mass – technology – mining”, formed as a result of mining activities. The main elements of geo-ecological risk in mining are dangerous geological (landslides, rock collapses, suffusion-erosion processes, karst, etc.) and hydrogeological processes. The purpose of the research. Development of a method for integrated assessment and management of geo-ecological risks in open-pit and underground mining operations. Methodology. The paper calculates the geo-ecological risk in relation to each technological process. At the same time, the ranking of the possibility of a negative process in mining activities is determined on the basis of an expert approach, taking into account the specifics of mining and technological operations. Statistical data and expert assessments formed the basis for determining the quantitative values of geo-ecological risks in mining operations. Results and discussion. The obtained quantitative values of geo-ecological risks indicate that a management system is needed. The developed geo-ecological risk management system makes it possible to conduct a comprehensive assessment of them in the conditions of mining and mining and construction production and, based on forecast calculations, determine the distribution zones of the most dangerous processes in the “rock mass – technology – mining” system. Conclusion. Research has been conducted on the formation of a comprehensive assessment of geo-ecological risks, as well as their forecasting during open-pit and underground mining operations. It is determined that the geo-ecological risk in open-pit mining consists of the risk of alienation and degradation of soil, the risk of pollutants into the atmospheric air, the risk of pollution and depletion of the water basin, and in underground mining – from the risk of atmospheric pollution of the working area, the risk of changes in the groundwater regime and the risk of geo-mechanical transformations of the rock mass.

Influence of Structural Discontinuity on Slope Stability using Numerical Modelling and Sirovision

The rock mass consists of heterogeneous and anisotropic materials, with smaller and larger blocks of rock, and the presence of structural discontinuities is a significant concern. Characterising the rock mass is crucial for the success of engineering excavations in such areas. A detailed study of joints, their orientation, and discontinuities in the exposed rock mass is crucial as they greatly influence stability and fragmentation. Existing rock mass classifications like Rock Mass Rating (RMR) and Q-classification require various geological parameters and physico-mechanical properties of the rock. However, determining these parameters conventionally can be time-consuming, requiring careful on-site measurements. The number of opencast coal mines is increasing compared to underground mines due to shorter gestation periods, higher productivity, and quicker returns. However, opencast mining raises environmental concerns such as air and water pollution, solid waste management, land degradation, and socio-economic issues. Additionally, many opencast coal mines, regardless of size, are reaching greater depths, making analysing bench slopes and ultimate pit slope design crucial. Slope failure in these mines leads to production loss, additional costs for recovery and handling of failed material, pit dewatering, sometimes mine abandonment or premature closure, and loss of life. A study was conducted at Prakash Khani Opencast Mine – IV, Manuguru area, M/s The Singereni Company Collieries Limited (SCCL), to investigate the influence of structural discontinuities on slope stability. SIROVISION software was used to assess rock mass characterisation, while PLAXIS-2D software was employed to analyse the influence of structural discontinuities on slope stability. A comparative conclusion was drawn based on the results obtained from SIROVISION and PLAXIS-2D analyses. The study revealed that the RMR of the mine ranged from very poor to fair due to numerous discontinuities. It was also found that discontinuities in the slope decrease the Factor of Safety (FOS), indicating an impact on slope stability.

Numerical Investigation into Factors Affecting Stability of Opencast Coal Mine's Rise Side Highwall Slope

Open-pit coal mining accounts for 93% of India's total coal production, playing a significant role in meeting the nation's substantial energy needs. The success of an open-pit mine hinges on maintaining the steepest and deepest slopes that remain stable over the mine's lifespan. However, slope failure is a complex issue influenced by numerous factors. In the context of openpit coal mines, the rise side highwall involves cutting through a rock mass containing various elements like an unconsolidated weathered mantle of sandstone, sandy clay, clay, carbonaceous shale and coal. Some opencast mines within the Godavari Valley Coal Field (GVCF), India have encountered significant pit slope failures. This paper uses a numerical modelling approach aimed at effectively assessing the stability of the rise side highwall, leveraging available geotechnical data from one of GVCF's largest opencast coal mines. The research investigates the impact of seven detrimental factors on slope stability, including dynamic loading due to blasting, employing a methodical One-Factor-At-A-Time (OFAT) approach. The study utilises Rocscience Phase2 version 9.0, a Finite Element Method (FEM) based numerical modelling software to gauge the sensitivity of each factor on the Factor of Safety (FoS). The numerical modelling results indicate that there is a linear decrease in FoS corresponding to the reduction in cohesion and an exponential increase in the FoS as the angle of internal friction rises. Furthermore, the analysis reveals significant impacts on the FoS due to groundwater and seismic loading from the blasting. This approach aims to comprehensively analyse and understand the intricacies of slope stability in the specific context of open-pit coal mining.

A novel model for sustainable production scheduling of an open-pit mining complex considering waste encapsulation

This work presents a novel mixed integer programming model for simultaneous optimisation of ore production and waste dumping schedule for an open-pit mining complex. The model maximises net present value and generates an optimal flow of materials from multiple sources (open pits, stockpiles) to destinations (processing streams, stockpiles, waste dumps) within the supply chain of a mining complex. In addition, the proposed model implements sustainable mining practices as it ensures the responsible disposal of potentially acid forming waste. An application of the new simultaneous and the traditional two-step (or sequential) methods confirms that the proposed method derives higher net present value and reflects a distinct advantage in addressing the acid mine drainage problem through encapsulation of potentially acid forming wastes. In addition, the results reveal that the new model requires less waste haulage work leading to a significant reduction in greenhouse gas emissions.

Slope Monitoring Techniques in Opencast Mines: A Review of Recent Advances

The process of excavating rock mass induces changes in the stress distribution within the slope, rendering it prone to deformation over a specific duration. The potential consequence of movements along the weak planes is the ultimate breakdown of the slope. Various monitoring techniques, including visual inspection, laser scanning, Lidar scanning, total stations, Global Positioning Systems (GPS), state-of-the-art radar scanning, and micro-seismic monitoring, are currently employed in mining environments to forecast slope failure and deformation rate. This article will discuss the need to implement a continuous slope monitoring system, including categorizing such systems and an overview of the current state of existing slope monitoring technologies. The paper also discusses the applications of UAVs (Unmanned Aerial Vehicles) in slope monitoring. The research proposes implementing a consistent and continuous slope monitoring strategy grounded on empirical data when planning big and deep opencast mines. This approach is crucial for guaranteeing optimal safety measures and enhanced productivity levels.

Application of Mining Width-Constrained Open Pit Mine Production Scheduling Problem to the Medium-Term Planning of Radomiro Tomic Mine: A Case Study

Application of Mining Width-Constrained Open Pit Mine Production Scheduling Problem to the Medium-Term Planning of Radomiro Tomic Mine: A Case Study

Evaluation of rock stability challenges affecting the formation of sustainable pit lake towards mine closure following crown pillar extraction in open pit-underground mines

The extraction of high-grade ore from the crown pillar (CP) in open pit-underground mines poses stability challenges and potential environmental risks. While an open pit has the potential to transition into a pit lake, the extraction of CP can induce failure in the surrounding walls, preventing the formation of the lake. There is also a concern that the backfilling material may not effectively confine toxic water within the pit, thereby risking contamination of the underground environment. To address these issues, a case study was conducted using FLAC3D and 3DEC models to evaluate the extent of failure caused by CP extraction. On-site observation, along with modelling, has revealed rock damage, including deformation stretching about 4 m from the pit wall and extending vertically from the pit floor to the ramp. The study identified three primary factors leading to pit wall failure or damage: steep pit slopes reaching approximately 70° near the pit floor, an underestimated CP thickness by about 4 m, and the concurrent extraction of ore from the pit wall alongside CP. Based on these findings, rehabilitation measures are suggested, including excavation of the deformed wall and cantilever, as well as partial pit backfilling. There is a substantial increase in the volume of backfill material as the extent of failure increases, which raise concerns about the decision-making process regarding CP extraction. Therefore, this article aims to raise environmental awareness and evaluate whether the benefits of ore extraction outweigh the considerations for pit wall support and the rehabilitation efforts during mine closure.

Metagenomic analysis reveals the effect of revegetation types on the function of soil microorganisms in carbon and nitrogen metabolism in the open-cast mining area

Metagenomic analysis reveals the effect of revegetation types on the function of soil microorganisms in carbon and nitrogen metabolism in the open-cast mining area

Evaluation of Coarse Gold-Bearing Conglomerate Mineralisation at Beatons Creek, Pilbara, Western Australia: Sampling for Resource Development and Grade Control

Many styles of gold mineralisation are challenging to sample because of the presence of coarse gold and a high spatial heterogeneity. The coarse gold-bearing conglomerates of the Beatons Creek deposit provide some challenges related to the presence of gold particles up to 8 mm and gold particle clusters (up to 500 mm3) at low in situ grades (<2 g/t Au). Novo has attempted to address these issues over the last six years of exploration, resource development and mining. The Beatons Creek open pit operation was the first Pilbara conglomerate-hosted gold deposit to go into production. Between January 2021 and September 2022, it produced 2.5 Mt at 1.2 g/t Au for 87,300 oz Au recovered. Gold is present within a matrix of multiple, narrow-stacked oxide and fresh (sulphide) conglomeritic reef horizons, which are interbedded with unmineralised conglomerate, sandstones and grits. It is strongly associated with detrital pyrite and authigenic nodules. Several sampling techniques have been applied across the project, including diamond core and RC drilling, trench channel sampling and bulk sampling. Assay methods applied include fire assay, screen fire assay, LeachWELL™ and more recently PhotonAssay™. The dominant sampling protocol applied for resource development and grade control utilised 0.5 m length RC samples; a 50% rig split (c. 8.5 kg) and laboratory crushing to 3 mm, followed by a 2.5 kg split and total assay via PhotonAssay™. For part of the 2022 RC programme, the detectORE™ technique was used to screen primary RC samples and reduce the feed to the laboratory. Novo operated a sampling and assay programme that aimed to reduce the impact of coarse gold on sample and assay preparation biases and to improve estimation.

New findings of gymnosperms in the Middle Jurassic of the East European platform

The plant-bearing layers in the Stoilensky open mine (Belgorod Region, Russia) are dated to the middle Bathonian–early Callovian based on the dinoflagellate cysts and spore-pollen assemblages, and in the Mikhailovsky open mine (Kursk Region, Russia) – to the middle–late Bathonian based on palynological data. Representatives of Pseudotorellia are recorded in the Middle Jurassic of the Belgorod and Kursk regions for the first time. A new species, Pseudotorellia oskolica, is described from the Stoilensky open mine based on the unique morphological and epidermal features. Leaves of this species are very narrow, they are characterized by the presence of stomata on the adaxial leaf surface. The type material of Czekanowskia europea from the Middle Jurassic of the Pripyat depression in Belarus was restudied. The diagnosis for C. europea is provided, since only a description of this species was given in the original publication. Czekanowskia leaves are recorded from the Belgorod and Kursk regions for the first time. They are determined as C. europea based on the similar epidermal features as in the type leaves. A shoot of Pagiophyllum sp. and numerous leaf fragments of Podozamites sp. were found in association with C. europea in the Pripyat depression. These genera are recorded in Belarus for the first time. Findings of Pseudotorellia, Czekanowskia and Podozamites leaves in the Middle Jurassic floras of the East European platform are discussed.

Extraction of sand from the complex matrix of coal mining dump waste: A sustainable approach in Indian context

Dump waste generated by open cast coal mining industry is a significant global source of environmental pollution, land degradation and possesses threats to the environmental sustainability. After conducting pilot study, experimental investigations were conducted to study the reuse of waste rocks coming from mining as fine aggregates as a possible replacement of river sand. Physical, chemical and mechanical tests have been carried out in order to analyze in detail the interaction whether extracted sand is suitable in construction sector or not. The present study focuses on utilizing the overburden of the Sasti open cast coal mine of Western Coal Limited in the Chandrapur District of Maharashtra state, India for extraction of sand. Extracted sand contains minerals mainly quartz, alumina, and satisfies the prescribed permissible limit as per the Indian coal provisions for its use in construction work and observed to be equivalent to river sand. The compressive strength obtained with extracted OB sand after 28 days of curing was 29.294 MPa as compared to 33.153 MPa for the river sand for M25 grade of concrete. The focus of the study is on the reclaimed sand and its possible usages and not on the other components like clay of dump waste.

Analysis of the Advantages of Open Pit Mining

In the process of open-pit coal mining, the landslide phenomenon is very obvious, so for the safety of mine personnel and the smooth implementation of the project, studying the stability of the slope angle is an extremely important task. There are many factors that affect the stability of the slope, such as soil quality, climatic conditions, later pressure, etc., this project takes the open-pit mine as the research object, calculates the slope coefficient through geological data exploration combined with program analysis method, and then sets up a soil dump near the mining area, so as to improve efficiency, project safety and planning maximum benefits.

Research on prediction of PPV in open-pit mine used RUN-XGBoost model

The drill-blasting method is a commonly used mining technique in open-pit mines, and the peak particle velocity (PPV) caused by blasting vibrations is an important indicator for evaluating the rationality of blasting mining design parameters. To develop an effective PPV prediction model, a parameter self-optimizing RUN-XGBoost prediction model is implemented using the Runge-Kutta optimization algorithm (RUN) combined with extreme gradient boosting (XGBoost). The factors affecting the prediction of PPV, including maximum explosive (ME), total explosive (TE), blast center distance (BCD), blast hole depth (BHD), and height difference between the measurement location and the blast location (DH), are selected as the influencing indicators. 188 pieces of blasting operation data were measured at the RK open pit copper-cobalt mine. Then, the RUN-XGBoost prediction model for PPV is studied and compared with the Sadovsky empirical formula, traditional XGBoost model, PSO-XGBoost model, and some traditional machine learning models (Ridge, LASSO, SVM, and SVR) using R2, RMSE, VAF, MAE, and MBE as evaluation indicators for model prediction results. Finally, the Shapley Additive Explanations (SHAP) method is used to evaluate the contribution of different influencing indicators to the PPV prediction results. The results show that the RUN-XGBoost prediction model is significantly better than other machine learning models and the Sadovsky empirical formula in the prediction of PPV, further demonstrating that the RUN-XGBoost prediction model can handle the nonlinear features of multiple factors and provide a reliable, simple, and effective PPV prediction model, forming a rapid prediction and evaluation method for blasting vibrations in open-pit mining.

Tracking deformation velocity via PSI and SBAS as a sign of landslide failure: an open-pit mine-induced landslide in Himmetoğlu (Bolu, NW Turkey)

A destructive landslide occurred in Himmetoğlu village in Göynük District (Bolu, NW Turkey) caused by open-pit coal mining activities. Field observations after the landslide failure and interviews with villagers motivated us to question the possibility of using satellite SAR data to detect precursory signs of failure with regard to deformation velocity. In this study, first, landslide deformations were mapped by applying the digital elevation model (DEM) of Difference (DoD) method using DEMs from aerial photography and UAV data. However, the primary aim was to track deformation velocity as a sign of landslide failure with persistent scatterers interferometry (PSI) and small baseline subset (SBAS) methods from Sentinel-1A data. For the SBAS, the deformation velocity for ascending and descending orbits varied between − 12 and 39 mm year−1 and between − 24 and 6 mm year−1, respectively. For the PSI, the deformation velocity for ascending and descending orbits varied between − 16 and 31 mm year−1 and between − 18 and 20 mm year−1, respectively. PSI and SBAS resulted in sharply changing line-of-sight displacement rates, which were interpreted as slope failure signs, from three months prior to the landslide. In addition, higher deformation velocities were observed in locations closer to landslide crack as expected. Based on our findings, we concluded that SAR interferometric time-series analysis have the makings of being used as a suitable approach in early discerning and avoiding potential slope failures in open-pit mining areas, when it is made carefully by observing the progress in mining activities by considering the other factors such as rainfall and earthquakes.

Solid waste characteristics and management strategies at ST Theresa (STT) and Holy Cross (HC) hospitals in Chirumanzu rural District, Zimbabwe

AbstractManagement of solid waste from rural hospitals is among major problems affecting developing countries. This is mostly attributed to inadequate data related to quantity and quality of hospital solid waste. Similarly, information related to rural hospital solid waste characteristics and management is limited in Zimbabwe. However, SDGs complemented by Zimbabwe Vision 2030, NDS 1 advocates for sustainable solid waste management. Hence, enough data related to characteristics of solid waste from rural hospitals are required to attain sustainability. This research focuses on hospital solid waste characteristics and management strategies at STT and HC rural hospitals. Descriptive cross sectional research design which triangulates qualitative and quantitative paradigms was utilized. Interviews, observations, questionnaires were used to collect data. Quantitative data were analyzed using Statistical Package for Social Sciences whereas qualitative data were subjected to content analysis. Solid waste generated at STT encompasses non-hazardous (77.35%), hazardous waste (22.65%). At HC solid waste consists of non-hazardous (79%) and hazardous waste (21%). Respondents at STT (70.4%) and HC (72.7%) noted that solid waste was increasing. Solid waste was increasing due to various factors namely high use of disposable materials at HC (35.1%), STT (42.5%) and increase of patients at HC (30%) and STT (29.7%). Solid waste was indiscriminately stored in various types of containers although pedal operated bins and sharp containers were highly used at STT (72.4%) and HC (69.1%). Waste receptacles were transported to disposal sites using wheelbarrows and manual handling. Open pits and burning were among disposal strategies but incineration was regarded as the golden approach at STT (44.8%) and HC (41.8%). Inappropriate hospital solid waste management was due to shortage of finance at STT (38.1%) and HC (30.9%) and unawareness among health workers. Although it was worsened by lack of all stakeholder participation at STT (79.0%) and HC (76.4%). Consequently, the study recommended application of strategies which support circular economy, integrated approach, raising awareness of health workers and provision of enough resources to rural hospitals.