Mining Hazards Research Articles

An Analysis of the Impact of Mining Excavation Velocity on the Development of Gaseous and Gaseous Geodynamic Hazards in Copper Ore Mines

The hazards of gaseous geodynamic phenomena and rockbursts are among the most challenging to assess and classify. This perception arises from both a review of the literature and an examination of available instructions and regulations in underground mining facilities. The hazard of gaseous geodynamic phenomena in Polish copper ore mines only appeared in 2009, whereas these phenomena occur and are commonly described in other mining countries. In Polish copper ore mines, due to the room and pillar system in fields with lengths of about 460 m, very often parallel to neighboring fields, which together give a length of about 900 m, it is difficult to identify the location of gas traps due to the large size of the area. This paper presents an analysis of the influence of the velocity of the excavation on the possibility of escalating or reducing the described mining hazards. An analysis of the impact of excavation velocity on the state of gaseous geodynamic and roof fall hazards was conducted for two mining fields. For the considered mining fields, the hypothesis was formulated that an excavation velocity greater than or equal to 17 m/month positively influences a reduction in both gaseous geodynamic and roof fall hazards.

An investigation of fracture modes around a spherical cavity for understanding outburst propagation mechanism

AbstractOutburst of coal and gas is a major hazard in underground coal mining where coal seam gas content/pressure is high. A cone‐shaped cavity is often observed in the coal seam after bursting, implying the likely mechanical structure being formed during outburst propagation. Although the mechanism for outburst initiation and propagation is very complex, mining‐induced fracturing and damage of the coal material is an essential component. This paper investigates the mechanical conditions that are essential to initiate fractures around a spherical cavity, a simplified form of the cone‐shaped outburst cavity. The cavity is assumed to be situated in an infinite isotropic homogeneous elastic body under internal gas pressure and far‐field hydrostatic compressive stresses as a further simplification for analytical investigation. The analytical conditions under which circumferential and radial fractures can initiate around the cavity are formulated, based on extensional strain criterion for fracture initiation. Low internal pressure on the cavity surface and high far‐field compression lead to circumferential fractures. In contrast, high internal pressure and low far‐field compression lead to radial fractures. Subsequent numerical simulations with FRACOD3D and FRACOD, the 3D and 2D in‐house fracture simulation codes, were carried out to investigate fracture patterns around a cavity and inclusion. The simulation results confirmed the analytical results, including fracture shapes and the size of fractured zone. These results provide a new angle to understand the complex mechanism of outbursts.

Identification and categorization of hazards in the mining industry: A systematic review of the literature

AbstractControl of OHS risks in the mining industry has been attracting increasing attention in recent years. Because of their great diversity in a complex system, hazards can be difficult to identify and classify, especially when system components interact. Risk cannot be managed successfully without comprehensive investigation of all its aspects. A coherent and integrated classification for identifying and categorizing all hazards is currently lacking in mining. We propose an integrated system classification of OHS hazards in mining based on our review of 44 studies retrieved using PRISMA. Considering Canadian and international standards, regulations and conventions, new hazard categories are proposed and hazard prevention is discussed from 12 perspectives: physical, chemical, biological, ergonomic, accident and psychosocial risks, as well as policy, legislation, management, design, geography, and uncertainty, with reference to each of the four phases of a typical mine life cycle, the hazards were shown in a portrait. This paper provides suitable categories based on rational data for creating a portrait in order to OHS hazards prevention in life cycle activity in mine.

Strength distribution of cemented waste rock backfill: a similarity simulation experiment

Backfill of cemented waste rock into underground mined-out areas is an effective way to eliminate solid wastes and potential hazards in mines. To understand the backfill strength distribution law throughout the stope, similarity simulation experiments were conducted for direct-irrigating cemented waste rock backfill, and OpenCV and neural network were employed to analyze particle segregation and the spatial distribution of backfill strength. Results show that distinct gravitational segregation leads to an uneven and heterogeneous distribution of natural graded waste rocks in a similar model. Backfill strength near sidewalls and bottom of the model surpasses that of other areas. In the vertical direction, the average backfill strength increases with depth, ranging from 1.15 MPa at the topmost layer to 1.91 MPa at the bottommost layer. Horizontally, the average backfill strength near model boundaries is consistently higher than that at the model center, irrespective of the layer depth and orientation. Neural network prediction on spatial backfill strength proves reliable, exhibiting an average relative error of 4.12%, compared to the traditional surface fitting with a 10.20% error. Verification tests affirm the capability of the neural network model to accurately predict the anisotropic and nonlinear distribution of backfill strength in a large stope.

Hierarchical fuzzy comprehensive evaluation of prevention and control level of occupational hazards in coal mines

Objective: To establish an evaluation model for occupational hazard prevention and control levels in coal mines, to explore the combination of Analytic Hierarchy Process (AHP) and fuzzy comprehensive evaluation, to evaluate the overall situation of occupational hazard prevention and control in coal mines. Methods: In November 2021, Collect information of occupational hazards and their prevention and control status in 30 coal mines. AHP model was first constructed for the elements of occupational hazard prevention and control in coal mines. Then, the AHP and fuzzy comprehensive evaluation method was applied to comprehensively evaluate and grade the occupational hazard prevention and control in coal mines, using the principles of maximum membership and weighted average. Results: The hierarchical fuzzy comprehensive evaluation results for typical coal mine were basically consistent with its occupational hazard prevention and control situation. The dust prevention and control situation was good, the noise prevention and control situation is average, the occupational health monitoring situation was good, the occupational health management situation was average, and the overall level of occupational hazard prevention and control was good. Conclusion: The hierarchical fuzzy comprehensive evaluation model for occupational hazard prevention and control levels, combined with the principles of maximum membership and weighted average, can objectively evaluate and reflect the overall situation of occupational hazard prevention and control in coal mines.

Assessment of self-perceived risk and risk rating among chemical sprayers in selected tea plantations in South India

Introduction: Chemical sprayers of the tea plantation industry perceive various degrees of risk involved in their daily work. The objective of the study was to assess self-perceived risk and to rate these risks among the pesticide sprayers working in selected tea plantations in South India. Methods: A cross-sectional study was conducted among 290 chemical sprayers in six selected tea plantations in South India from September to October 2018 after approval from the Institutional Ethics Committee and permission from the plantations. Data was collected by structured interview schedule with the chemical sprayers and key informant interviews were conducted with their supervisors. The risks perceived by the sprayers were rated and expressed using the Risk Rating Matrix. Results: The mean age of the participants was 45.6±8.5 years and all of them were males. The most common risks encountered were leech bites (76%), other insect bites (58%) and bruises (46%). Chemical spills, splashes, slips, falls and backaches were considered as minor hazards in risk rating. Animal attacks and falls from trees were assigned the highest risk rating scores. Conclusion: Insect bite was the most common risk perceived and animal attacks attained the highest risk score. Regular supervision and monitoring of work-related risk factors can help in the reduction of common injuries thereby ensuring safety at the workplace.

Damage features and dynamic triggering mechanism of the Jianshanying landslide induced by underground mining in Shuicheng County, Guizhou Province, China

Extensive mining of mineral resources in the mountainous areas of southwestern China has caused frequent occurrences of landslides, threatening social and economic development. Therefore, further research on the formation mechanism of such landslides is urgently investigated. Using detailed geological investigations, a numerical simulation, and related theoretical analysis reveal the dynamic triggering mechanism, influencing factors, and mechanical evolution model of the Jianshanying landslide under the coupled action of heavy rainfall and mine blasting vibrations. Results showed the following: First, rainfall of about 5 days, which nearly saturated the slope, and nearly 3 blasting cycles (peak horizontal and vertical velocities of 0.3375 and 0.1573 cm/s, respectively) executed close to it were the main controlling factors inducing the landslide. Second, the macroscopic deformation of the slope manifested obvious subsidence and tipping, and the maximum vertical and horizontal displacements of the slope shoulder reached 13.466 and 2.961 m, respectively. Third, the critical failure of the slope occurred at 15 s in the dynamic analysis, and its subsequent responses involved disintegration and fragmentation, debris flow, scraping of the sliding bed, and self-stabilized accumulation. Finally, its mechanical evolution model was divided into the subsidence stage and the shear-tension stage. These results provide technical support for early identification and risk management of geological hazards in mines in southwestern China.

Fuzzy inference system using genetic algorithm and pattern search for predicting roof fall rate in underground coal mines

One of the most dangerous safety hazard in underground coal mines is roof falls during retreat mining. Roof falls may cause life-threatening and non-fatal injuries to miners and impede mining and transportation operations. As a result, a reliable roof fall prediction model is essential to tackle such challenges. Different parameters that substantially impact roof falls are ill-defined and intangible, making this an uncertain and challenging research issue. The National Institute for Occupational Safety and Health assembled a national database of roof performance from 37 coal mines to explore the factors contributing to roof falls. Data acquired for 37 mines is limited due to several restrictions, which increased the likelihood of incompleteness. Fuzzy logic is a technique for coping with ambiguity, incompleteness, and uncertainty. Therefore, In this paper, the fuzzy inference method is presented, which employs a genetic algorithm to create fuzzy rules based on 109 records of roof fall data and pattern search to refine the membership functions of parameters. The performance of the deployed model is evaluated using statistical measures such as the Root-Mean-Square Error , Mean-Absolute-Error, and coefficient of determination (R_2). Based on these criteria, the suggested model outperforms the existing models to precisely predict roof fall rates using fewer fuzzy rules.

Research on the prediction of impact ground pressure hazard in deep coal mining based on moving average method

Research on the prediction of impact ground pressure hazard in deep coal mining based on moving average method

Bituminous geomembranes in mining applications in the Americas

Bituminous geomembranes (BGM) have been used over the last 20 years in mining applications in innovative ways, to reduce the hazards of mining in the environment. BGM is a reinforced geomembrane made of a geotextile from 250 gr/m² to 400 gr/m2 impregnated by elastomeric bitumen. This gives the geomembrane unique features that enables their use in demanding weather conditions of low temperatures (– 45°C or -49°F in Northern Canada or Europe) or high temperatures (+40°C in Brazil) due to its low thermal expansion coefficient that avoids the formation of wrinkles. This allows the installation and welding at high temperatures in the countries of Latin America. This paper will describe how several unique characteristics have been used for challenging and environmentally sensitive mining projects throughout the Americas, including treatment of solid waste spoil dumps (heap leach pads, closure, and encapsulation of mining facilities) of different types of ore: gold, diamonds, lithium, copper, silver, rare earth: niobium and in hydraulic applications for tailings or clear water dams and reservoirs.

Simulated and experimental study on effect of thermal insulation layer on temperature field and heat dissipation of roadway surrounding rock

As mining activities extend deeper, intense heat dissipation from surrounding rock has become the most significant factor leading to heat hazards in deep mines. Laying the thermal insulation layer (TIL) along the roadway walls is an effective measure to reduce heat dissipation. This study is to investigate the temperature field and heat dissipation evolution of roadway surrounding rock after applying thermal insulation layer (TIL) by numerical simulation and similar experiment. The study shows that (i) The simulation curves agree well with the experimental data, which confirms the reliability of the mathematical model and numerical simulator; (ii) The application of TIL slows down the cooling of surrounding rock temperature field, the cooling ring radius decreased by 8.13 % after 10 years of ventilation; (iii) The effect of TIL on the equivalent thermal resistance (ETR) is most significant in early ventilation, and the thermal insulation effect decreases with time; (iv) The heat insulation rate is positively correlated with the TIL thickness and the convective heat transfer coefficient, and negatively with the thermal conductivity of TIL. This study provides the theoretical basis for the use of thermal insulation materials in underground mines.

Fault complexity degree in a coal mine and the implications for risk assessment of floor water inrush

Faults significantly affect the stability of surrounding rock and stress distribution, which increases the possibility of water inrush disasters in a coal mine. Also, the precisely advanced prevention and control of floor limestone water become the foundation of ensuring mine safety and efficient production in coal mines. Fault development evaluation is one of the elements that control further transparent and fine studies. In this paper, the fault control index (FCI) is built based on the fractal dimension (Ds) and fault influence factor (E), which is determined according to the measured water inflow of water inrush points. The box meshing level is analyzed to calculate and compare the FCI. The results show that the box-meshing level affects the value of Ds and FCI and a meshing level of 6 seems to be the minimum standard of Ds for high accuracy. To verify the results, a comprehensive risk evaluation model of floor water inrush is established to illustrate the implications of fault complexity degree on safety mining. A stricter meshing grade when using the box-counting method in fault complexity degree is necessary for further studies in the precise prevention and control of mine hazards.

Evolution of Water-Conducting Fracture in Weakly Cemented Strata in Response to Mining Activity: Insights from Experimental Investigation and Numerical Simulation

The accurate prediction of the vertical extent of water-conducting fracture (WCF) zones in weakly cemented strata is particularly significant in preventing and controlling water hazards in western coal mines. The evolution of fractures in weakly cemented strata affected by mining disturbances was comprehensively analyzed by physical similarity models, numerical simulations, and field investigations. Results indicated that the development progress of water-conducting fractures can be divided into three phases: initial slow generation, subsequent rapid development, and eventual stabilization. The numerical simulation results revealed that in the initial stage of working face mining, the development of the plastic zone is limited, and there is minimal failure in the overlying strata; therefore, fractures are slowly produced without penetrating through the strata. When the plastic zone fully encompasses the entire main roof, it triggers severe shear failure in the overlying strata, resulting in rapid fracture propagation and penetration. Once the fracture height reaches a stable state, there is no further increase in the maximum vertical displacement of key strata, indicating the extensive collapse and compaction of the overburden as well as the stabilization of the fracture heights. A modified prediction equation for WCF in weakly cemented strata was obtained by correcting the traditional empirical formula based on field investigations. This modified prediction equation enhances the accuracy in predicting fracture heights and provides a theoretical reference to address the issue of the inaccurate prediction of the water-conducting fracture height in western mine rock strata.

Molecular dynamics study on the effect of inorganic salts on the wettability of surfactants on bituminous coal: Sodium dodecyl sulfate and sodium chloride as representatives

To further enhance the wetting ability of surfactants to coal, the mechanism of improving the wetting performance of SDS to bituminous coal by the addition of inorganic salt NaCl was studied through a combination of molecular dynamics (MD) simulation with experimental measurements. In the experiment part, the surface tensions of the mixed NaCl-SDS solutions and the contact angles on the bituminous coal surface were measured. Furthermore, MD simulations were conducted to investigate the adsorption characteristics and wetting mechanism of a mixed NaCl-SDS solution on the coal surface at the atomic scale. In this process, the static potentials of the H2O molecule, coal molecule and SDS molecule were calculated, and the number of hydrogen bonds (H-bonds) formed throughout the whole simulation process, the average H-bond length, the relative concentration distribution (RCD) curve and the mean square displacement (MSD) curve were obtained. The experimental results showed that the surface tension and contact angle were both decreased by the addition of sodium chloride in mixed solutions. When 0.6 mol/L NaCl was added, the surface tension and contact angle reached the minima of 30.45 mN/m and 13.01°, respectively. The MD simulation results showed that, after the addition of NaCl, diffusion and migration of H2O molecules were limited, the number of H-bonds increases, the average bond length decreased, the sorption between H2O molecules and coal molecules was enhanced, and the hydrophilicity of coal surface was improved, which meant that the wetting ability of SDS solution to bituminous coal was enhanced by adding NaCl. The effect of the added NaCl in improving the wettability of SDS on coal was explored from two perspectives with macroscopic experiments and microcosmic simulations, and the added NaCl improved the effects of dust suppressants, and played a key role in preventing dust hazards in coal mines.

Study on monitoring nucleic acid contamination in laboratory and its application

Monitoring nucleic acid contamination in laboratories is essential for ensuring the accuracy and reliability of polymerase chain reaction (PCR) assay results. Compared to traditional chemical reagent-based extraction, magnetic bead extraction is a targeted adsorption method for extracting DNA, offering greater efficiency and minor hazard. However, the effectiveness of this method in detecting nucleic acid contaminations in laboratory remains unclear. This study aimed to develop a PCR-based laboratory environmental monitoring method to investigate the effectiveness of magnetic bead extraction for detecting nucleic acid contamination. To mimic nucleic acid contamination, Staphylococcus aureus was aerosolized in a PCR laboratory. Following sampling, nucleic acid extraction was performed using the magnetic bead extraction method. Samples were analyzed using quantitative real-time fluorescence PCR (qPCR), and the concordance between the magnetic bead extraction results and theoretical results was assessed. This study presents a PCR laboratory nucleic acid contamination monitoring protocol. The results demonstrated that the nucleic acid detection outcomes obtained using the magnetic bead extraction method were consistent with the theoretical results across all regions tested using this protocol. The magnetic bead extraction method demonstrated comparable detection outcomes to the theoretical results in monitoring laboratory environments. This approach provides a more efficient and environmental friendly method of monitoring the laboratory environment.

Analisis Resiko Terkait Kecelakaan Kerja di Tambang Batubara dan Faktor Risiko Terkait

Mining operations need to recognize potential hazards, evaluate the risks involved, and continuously control risk to a manageable level. In addition to statistical data, other factors contributing to the rise in industrial accidents in businesses include the effective tunnel temperature, which is between 27 and 29 °C, hazardous mine gases, employee neglect of personal protective equipment, and a lack of hazard awareness in some workplaces. Based on these issues, the study's objectives are to illustrate how corporate OSH is used, provide data on work accidents and potential risk factors in the workplace, and make recommendations for a number of work practice guidelines. The world's most hazardous occupation is mining. the Ministry of Energy and Mineral Resources' statistical data. In mining, accidents frequently happen. Hazardous field conditions, unsafe work practices, and a disregard for safety are the root causes of dangerous working circumstances. As a result, fatal work accidents frequently happen. In order for businesses and employees to reduce the risk of work accidents, this research's goal is to identify the factors that lead to accidents at work in the coal mining industry. Data sources for this study were gathered from "Google Scholar" using the keywords "The year of publication is limited to 2018–2022." This study used the systematic literature review (SLR) technique. Risk variables are the most crucial elements employed in preventing work accidents, according to a study of the literature on how age, job experience, the workplace, and body parts affect employee work accidents., and the role of the company in influencing the occurrence of accidents. work accident.

A method to predict rockburst using temporal trend test and its application

Rockbursts have become a significant hazard in underground mining, underscoring the need for a robust early warning model to ensure safety management. This study presents a novel approach for rockburst prediction, integrating the Mann-Kendall trend test (MKT) and multi-indices fusion to enable real-time and quantitative assessment of rockburst hazards. The methodology employed in this study involves the development of a comprehensive precursory index library for rockbursts. The MKT is then applied to analyze the real-time trend of each index, with adherence to rockburst characterization laws serving as the warning criterion. By employing a confusion matrix, the warning effectiveness of each index is assessed, enabling index preference determination. Ultimately, the integrated rockburst hazard index Q is derived through data fusion. The results demonstrate that the proposed model achieves a warning effectiveness of 0.563 for Q, surpassing the performance of any individual index. Moreover, the model's adaptability and scalability are enhanced through periodic updates driven by actual field monitoring data, making it suitable for complex underground working environments. By providing an efficient and accurate basis for decision-making, the proposed model holds great potential for the prevention and control of rockbursts. It offers a valuable tool for enhancing safety measures in underground mining operations.

TENORM radiation protection patterns for the sustainable health of workers

Background: Coal production in Indonesia continues to increase to meet national energy needs and export demand. Solid waste from the coal combustion process is estimated to increase significantly. One of the hazardous mining wastes is TENORM, but some TENORM is classified as production goods with economic value. The problem in this research is that the volume of waste containing TENORM is quite large, and the disposal, use, and recycling of TENORM has the potential to cause contamination for workers at the steam power plant and the surrounding environment. Objective: The purpose of this research is to obtain a design model for the protection of the environment and workers against TENORM radioactive waste from coal ash through an analysis of the social and economic perceptions of steam power plant workers regarding TENORM radiation and the effectiveness of TENORM radiation protection education to workers. Methods: A mixed method with a quantitative approach was applied. Data were gathered through field observation utilizing a questionnaire instrument that asked workers working at Steam Power Plant Units 1 – 7 a series of written questions. Results: Prior to Counseling, most Suralaya Steam Power Plant workers had shallow social and economic perceptions of TENORM radiation, with 88 percent unaware of its effects. The majority also paid between 100,000 and 500,000 IDR monthly in medical expenses. All respondents agreed that TENORM radiation safety counseling for Suralaya Steam Power Plant workers was utterly compelling, with acceptance of TENORM and WTP estimates following Counseling being the most important aspect. Conclusion: There was a significant relationship between the WTP variable after Counseling and the variables acceptance of TENORM protection (0.730), TENORM knowledge (0.627) before and after Counseling (after Counseling), and acceptance of TENORM protection (0.648), according to the pattern of protection for the SEM model.

Preventing water inrush hazards in coal mines by coal gangue backfilling in gobs: influences of the particle size and stress on seepage characteristics.

The backfilling mining method that fills gobs with coal gangue can prevent water inrush hazards, protect groundwater resources, and protect the ecological environment of the mining area. However, initial conditions including the particle size distribution of gangue and the stress environment may affect the seepage characteristics of gangue backfill and inrush prevention ability. Taking the particle size and stress as main controlling factors, the seepage tests were designed for gangue to evaluate influences of the particle size and stress on the void ratio, permeability, and non-Darcian flow factor of gangue. In the meantime, the four stages in dynamic changes of seepage channels were studied and the impervious envelope lines of gangue backfill materials were provided. The results show that the larger the particle sizes, the stronger the crushing resistance of particles; under high stress (> 6.67MPa), seepage channels in small gangue particles (< 5mm) change in a more complex manner, and the non-Darcian flow phenomena become more significant. The particle size and stress exert significant influences on the seepage characteristics. Therefore, when reducing water inrush hazards by gangue backfilling in gobs, the particle size distribution should be optimized by combining the stress and water pressure conditions. Seepage channels in gangue backfill materials vary with changes in the particle size and stress. Their variation can be divided into four stages: shrinkage of seepage channels, reconstruction of seepage channels, dynamic equilibrium between slight expansion and shrinkage, and persistence of the impervious effect. After the first and second stages have been fully developed, the preliminary impervious conditions are met; after full development of the fourth stage, the gangue backfill materials reach an impervious state.

Real-Time Detection of Safety Hazards in Coal Mines Utilizing an Enhanced YOLOv3 Algorithm

Real-Time Detection of Safety Hazards in Coal Mines Utilizing an Enhanced YOLOv3 Algorithm