Underground Mine Workings Research Articles

Reduced resting and task-related alpha activity in mine workers: Implications for occupational health and neurodegenerative risk

Underground mine workers face many risk factors at work sites that are known to affect the neural system. Observational studies report that these risk factors precede neuromuscular and neurodegenerative disorders, especially in old-age miners. Neurodegenerative disorders have electrophysiological, anatomical, and functional changes long before symptoms are seen in older adults. Therefore, this study investigated whether risks faced by miners at young ages were reflected in electrophysiological signals. Twenty-one underground miners and twenty-two above-ground workers matched with them in terms of age, education, and working duration were included in this study. Participants were recorded with a 20-channel EEG during the resting-state (eyes open and closed; EO-EC) and the perception of the International Affective Picture System Paradigm (IAPS). Time-frequency analyses were performed for alpha frequency. Rs-EEG results showed a statistically significant difference in alpha power between the EO and EC states in the control group. However, there was no statistical difference in alpha power between these two conditions in the miners. Additionally, we noted a more pronounced decrease in alpha responses in the posterior region during EC in the miners. The group's main effects were statistically significant in event-related alpha responses during emotional responses. Accordingly, event-related alpha responses of the miner group were lower than the control group in terms of both power spectrum and phase-locking. Underground mine workers are cognitively and emotionally affected by risks in the work environment. Electrophysiological changes seen in young underground workers may be a harbinger of neurodegenerative disorders in miners' old age. Our research findings may lead to the development of occupational neuroscience, social policies, and worker health, which are necessary to improve working conditions for mineworkers.

IOT Based Mining, Tracking and Worker Safety Helmet

Abstract: This project addresses a cost-effective, flexible solution of underground mine workers safety. A module of MEMS and temperature-based sensors are used for underground environment monitoring and automating progression of measurement data through IOT communication technique is proposed with high accuracy, smooth control and reliability. Arduino microcontroller is used for collecting data and making decision, based on which the mine worker is informed through server. Sensor data transforms into digital signal and effectively communicate wirelessly with the ground control centre computer.

Rock exfoliation in the unstable formations during underground mine working driving and selection of efficient adhesive compositions for strengthening

Purpose is to identify factors favouring rock exfoliation in roof of underground mine workings while operating Akbakay deposit and determine optimum structure of adhesive reagents for the rock strengthening taking into consideration mineralogical composition of the formation. Methods. The research was carried out in a lab environment. Chemical and ultimate composition of the rock mass samples was determined through x-ray diffraction method; the x-ray phase identification approach helped define their mineralogical composition. The optimum composition of adhesive reagents has been determined based upon the ambient temperature and hardening time. Viscosity durability of the adhesive compounds was assessed using a technique of uniaxial crack of the immovable samples. Statistical data processing involved determination of the required number of the samples to achieve the preset accuracy degree. Findings. Exfoliation of the fragments of both fractured and unstable rocks from Akbakai deposit depends upon availabi-lity of such chemically and mechanically unstable salts as dolomite, albite, and mirror stone. Epoxide reagent in 9 to 1 ratio with polyethylenepolyamine catalyzer has been identified as the most effective adhesive compound. Epoxy adhesives have demonstrated higher cohesive resistance to compare with polyurethane analogues, and better compliance with requirements as for viscosity and hardening time. Originality. Use of epoxy to strengthen both fissured and unstable rocks of Akbakai deposit containing mineral salts, helps increase tensile properties up to three times. Moreover, epoxies also demonstrate high adhesive characteristics; and they are resistant to moisture and temperature attacks being typical for mine environment. New logarithmic dependencies have been identified describing rock mass stability while applying the modified polyurethane with polyethylenepolyamine catalyzer in 9 to 1 ratio. Practical implications. Various types of reagents have been considered for safe and effective strengthening of underground mine workings in the fractured rock masses having a tendency to caving. The proposed adhesive reagents resist efficiently the external share loads and stresses increasing structural stability and safety of rock masses.

Job demands, control, social support and mental health in workers of thermal power plants and underground mines: A comparative study

This descriptive study was conducted to compare the job demands, job control, social support and mental health status of thermal power plant and underground coal mine workers. 158 workers in thermal power plant and 162 workers in underground coal mine participated in the study. The results unearthed that thermal power plant workers had 2.3 times better mental health (p < 0.001 OR = 2.3 CI = 1.50-3.74) and 3.0 times lower job demands (p < 0.001 OR = 3.0 CI = 1.91-4.92) than coal mine workers. In the study, it was determined that mental health was positively affected as job control and social support increased in both thermal power plant and underground mine workers (p < 0.05); there was no significant relationship between job demands and mental health (p > 0.05). These results indicate that underground mine workers are at higher risk in terms of mental health and job demands than thermal power plant workers.

A study on chronic obstructive pulmonary disease and its determinants among underground coal mine workers in Bankola area, Durgapur, West Bengal

Background: Chronic obstructive pulmonary disease is a leading cause of morbidity and mortality worldwide that effectuate an economic and social burden that is both considerable and progressive. Mortality from respiratory disease remains an important occupational hazard among coal miners. Inhalation of coal mine dust is known to cause several respiratory diseases including COPD. The current study aimed to estimate the prevalence of COPD among coal miners and to find out the predictors of the same in Bankola Area, Durgapur, West Bengal. Methods: A cross-sectional study was conducted among 315 coal miners selected by simple random sampling from the list of mines in Bankola Area, Durgapur, West Bengal. The required data was collected by face-to-face interview with the help of a predesigned pretested questionnaire and subsequently clinical examination along with spirometry in an eligible subset of population. Data thus collected had been analysed by SPSS 16.0 version. Results: Prevalence of COPD among mines was found to be 11.7%. Most of the miners showing obstructive pattern, had Grade 2 severity of airflow limitation (43.2%) whereas 8.2% had Grade 4 severity. Multivariate analyses revealed that miners who were smoking for more than 20 years, working in highly dusty areas and those who were working at coal face had higher odds of developing COPD. Conclusions: Addressing substance use as well as improvement in working environment including use of personal protective equipment can holistically lead to better respiratory health of the miners.

Assessing the hazard of diesel particulate matter (DPM) in the mining industry: A review of the current state of knowledge

In the confined spaces of underground mines, the exposure of over 10,000 miners in the U.S. to diesel exhaust and diesel particulate matter (DPM) is an occupational inevitability, particularly in metal and nonmetal mineral extraction. These workers routinely operate amidst diesel-powered equipment, often outdated and highly polluting, extracting resources such as limestone, gold, and salt. The acute health effects of such exposure are significant, leading to symptoms like headaches and flu-like conditions, with the impact being more pronounced in these closed work environments. This review scrutinizes DPM’s hazard in the mining sector, consolidating the extant knowledge and exploring ongoing research. It encapsulates our understanding of DPM’s physicochemical properties, existing sampling methods, health ramifications, and mitigation technologies. Moreover, it underscores the necessity for further study in areas such as the evolution of DPM’s physicochemical attributes, from its genesis at high-pressure, high-temperature conditions within diesel engines to its emission into the mine atmosphere. A key research gap is the intricate interaction of DPM with specific characteristics of the mine environment—such as relative humidity, ambient temperature, the presence of other mineral dust, and the dynamics of ventilation air. These factors can significantly alter the physicochemical profile of DPM, influencing both its in-mine transport and its deposition behavior. Consequently, this can affect the respiratory health of miners, modifying the toxicity and the respiratory deposition of DPM particles. Identified research imperatives include (1) the advancement of instrumentation for accurate number measurement of DPM to replace or supplement traditional gravimetric methods; (2) the development of long-lasting, cost-effective control technologies tailored for the mining industry; (3) an in-depth investigation of DPM interactions within the unique mine microclimate, considering the critical components like humidity and other aerosols; and (4) understanding the differential impact of DPM in mining compared to other industries, informing the creation of mining-specific health and safety protocols. This review’s findings underscore the urgency to enhance emission control and exposure prevention strategies, paving the way for a healthier underground mining work environment.

Разработка технологии проведения и крепления горной выработки в зоне тектонически-ослабленных пород

Presence of tectonically weakened and disturbed zones leads to decreased underground excavation rates and reduced safety of the mining operations. As a rule, such zones are bounded by vertical and subvertical disturbances that contribute to weakening and loss of stability of the rock and ore mass. Disturbance of the natural state, in particular driving of a mine workings, provokes irreversible deformations due to redistribution and concentration of stresses within the boundary rock mass, which is more rigid. At the same time no significant stresses are formed within the rock mass of the tectonic zone due to its caving. Therefore, when developing solutions for driving and supporting mining excavations within the tectonic zone, the rock mass should be considered as weakened and highly fragmented with unbonded structural blocks. The particle-size distribution within the rock mass of the tectonic zone varies in a wide range of sized from several to tens of centimetres. In this context, the mining and rock reinforcement technology presented in this paper accounts for the possible free caving of the non-bonded host rock mass made up of small-sized blocks. The paper discusses physical and mechanical characteristics and the stress-and-strain state of the rock mass within the tectonically weakened zone and the boundary host rocks, and a technology of driving and supporting underground mine workings is proposed on this basis.

CFD MODELLING OF THE DUST AND AIR VELOCITY BEHAVIOUR AT AN UNDERGROUND COAL MINE ROADWAY

Dust pollution for ventilation systems is a big problem for mine workers in underground coal mines. The respirable dust concentration is important to the physical and spiritual health of miners. It is hazardous up to 2 mg/m3in the air in underground coal galleries. In the present work, the airflow velocity and dust concentration values were measured at Çay 1-Kartiye roadway in Kozlu, Zonguldak. The goal of this research is modelling to the dust concentration and airflow velocity values by the computational fluid dynamics (CFD) method. An airflow and dust fluid and solid model was done using the Eularian-Granular multiphase method with the k-epsilon two-equation model. The results showed that dust concentration values were too low and fixed. The error percentage of airflow velocity values changed between 5% and 17%. Thus, this roadway is safe for coal dust explorations.

Assessment of the benefits of cooling vests on working conditions of mine operators in hard climatic conditions: A case study

The impact of high temperatures and humidity in the work environment on workers in underground mines can be harmful and even dangerous to health, contributing to body dysfunction and health issues. Overloading the body decreases physical fitness and work efficiency and increases the risk of health and life-threatening events. This study analyzed the practical possibility of reducing the body temperature of mine operators under harsh climatic conditions using cooling vests. The results showed the usefulness of cooling vests in daily work despite the need to replace cooling cartridges during work shifts.

Miner pose detection algorithm based on improved YOLOv7 in the coal mine

The unsafe behavior of workers in underground mines is a major cause of accidents. Recently, deep learning technology has become more and more widely used in the computer field and has achieved remarkable results, providing new opportunities for the research of miner behavior recognition algorithms. To address the current problem of large computation volume and low detection efficiency of multi-person posture detection in underground mines, we propose an improved algorithm that introduces the GSConv convolution module into the YOLOv7-Pose model and replaces the ELEN-W module with the GSELEN module to accelerate model convergence. We also introduce a group-convolution reconstruction SPPCSPC module to reduce parameter load and calculation amount and reduce the original 17 joint points to 14 joints to further realize a lightweight model. The experimental results showed that the improved YOLOv7-Pose model in this study decreased to 135.7 MB, by about 18.8%, while maintaining model accuracy. Therefore, this improvement can achieve a lightweight algorithm and improve real-time posture detection of construction workers in underground mines while ensuring model accuracy.

Assessing the stability of underground workings in urban infrastructure

This article presents the analytical formulas necessary for making optimal design and technological decisions when laying shallow underground mine workings. They make it possible to determine the following critical parameters of mine workings: the critical height of the lift of the arch of natural equilibrium is the surface above which the rock is in an undestroyed state; stability coefficient of the arch of natural equilibrium (it shows in what state the rock above the excavation is); critical rock pressure is the pressure that, if exceeded, causes the rock to collapse above the working without support; critical depth of the mine working; critical pressure in the pore fluid is the pressure above which the rock collapse above the working without support; design maximum rock pressure with a given safety factor; design maximum depth of the working with a given safety factor; rock pressure on the support.

Theoretical model for calculating and adjusting radon activity concentration in ventilation networks of uranium mines considering pressure drop effect

The radiation dose of workers in underground uranium mines mainly comes from radon and radon progeny. To ensure a healthy and safe work environment, it is necessary and urgent to optimize the design of ventilation systems. As such, based on the simplified radon diffusion-advection migration model of the rocks, this paper proposes 1) two methods for determining the radon exhalation rate modified by pressure drop, 2) three methods for calculating radon activity concentration of single-branch, and 3) the novel adjustment algorithm and solving procedures for calculating and adjusting the radon activity concentration in ventilation networks by modifying the radon exhalation rate, demonstrated on a specific ventilation network in a simulated underground uranium mine with calculation and analysis via MATLAB. The results show that 1) the radon exhalation rate of different branches can be modified by their pressure drop, and 2) the proposed method can be used to reveal the influences of different ventilation methods and fan pressures on the radon activity concentration in the ventilation network and the radon release rate to the atmosphere.

Using sectional blasting to improve the efficiency of making cut cavities in underground mine workings

Introduction: The research concerns how making cut cavities improves drilling and blasting operations as well as the optimum parameters to arrange both snubber and auxiliary blastholes.Methods: The research methods include experimental and industrial activities to identify the optimum depth of the first-section snubber blastholes relative to the second-section blastholes. It also identifies optimum parameters of the snubber blastholes while driving mine workings and ore breaking in stopes with different mine working sections and different rock mass strengths broken using the technique of cut-cavity formation.Results and Discussion: Experimental explosions executed in a production environment have proved the efficiency of the proposed technique of sectional formation of a cut cavity, which helped increase the blasthole use coefficient (BUC) from 0.88 to 0.97. The depth of the first-section boreholes should be determined relative to the length of the second-section boreholes and the broken rock mass strength. The higher the strength of the broken formation, the larger the ratio between the first and the second-section blasthole lengths should be. The results of the experimental explosions indicate that the depth of first-section snubber blastholes varies from 0.5 and more of the second-section boreholes, depending upon the depth of the latter and the broken rock mass strength. If the strength of the broken rock mass is 12 on the Protodyakonov scale, and the second-section blasthole depth increases from 1.6 m to 2.6 m, then the depth of the second-section boreholes should be increased from 0.9 m to 1.54 m so as to be 0.55–0.56 of the second section blasthole length. If the strength of the broken rock mass is 18, and the length of the second section increases from 1.8 m to 2.82 m, then the first-section length varies from 0.9 m to 1.75 m, being 0.5–0.62 of the second section blasthole length. Applying the novel proposed procedure for a cut-cavity formation will increase the blasthole use coefficient and reduce the cost of drilling and blasting operations. Moreover, the procedure may also be practical for driving underground mine workings and for ore breaking within stopes.

Снижение биокоррозии деталей оборудования, эксплуатируемого в подземных выработках за счет применения детонационного Ti-Cu напыления

Introduction. The wide distribution of microorganisms in the natural and technogenic environment, in the conditions of underground mine workings, is explained by their phenomenal adaptation capabilities. The high activity of microorganisms at significant depths under extreme conditions is due to the peculiarities of their metabolism. The maximum number of these factors is typical for underground mining. The lithosphere, in which underground structures are built to ensure the development of deposits, in addition to its well-known characteristics, is also a habitat for microorganisms. The waste products of these microorganisms significantly influence the rate of corrosion of metals. Often the scale and speed of bio damage are so significant. Therefore, the study of microbial bio damage processes and their prevention under these conditions is an extremely urgent task. Materials and methods. The corrosion rate in an aggressive biological environment of three types of samples was studied. The first type of samples were ordinary plates made of St 3. The second type of samples was the same St 3 but with antimicrobial enamel XC-5286 applied to the surface. And the third type of samples were samples made of St 3 with a detonation coating applied to their surface from a mixture of Ti (PTN-8VT10) and Cu (PMS-1) powders. These samples were exposed to a biologically active corrosive environment for one month. Then the level of damage and corrosion development on the surface of the samples was measured. Results. The results of the study showed that the use of the method of detonation thermal spraying makes it possible to form a protective Ti-Cu composite coating with anti-corrosion properties on the surface of low-carbon steel. The rate of biological corrosion of steel samples with Ti-Cu coating is 40% less than on control samples without such a coating. The anti-corrosion efficiency of the XC-5286 coating was 80%. Discussion. The antimicrobial effectiveness of Cu ions primarily depends on their concentration adjacent to the coating surface, which in turn is determined by the rate of release of biocide ions. When immersed in an aqueous solution, copper (I) oxide (Cu2O), which is part of both the XC-5286 coating and the Ti-Cu composite coating formed by thermal spraying, is unstable and, under the influence of chlorine, hydrogen and oxygen ions, quickly oxidizes to more stable divalent copper ions Cu2+. To maintain the required level of antimicrobial effect, the average rate of release of copper ions from contact-type coatings (which includes XC-5286) must be at least 50 μg/cm2 day. The rate of release of Cu ions from a composite Cu-Ti coating formed by plasma spraying is about 20.5 μg/cm2 day, which is almost 2 times less than the required level. This explains the lower antimicrobial efficiency (AE) of Ti-Cu composite coatings compared to XC-5286 enamel, which has an AE value of 80.5%. As shown by full-scale tests, even at low values of the release rate of Cu ions, the coating under study provides effective inhibition of the development of bio corrosion. Conclusions. The work established that the use of the method of detonation thermal spraying made it possible to form a protective Ti-Cu composite coating with anti-corrosion properties on the surface of low-carbon steel. Resume. The work established that the use of the method of detonation thermal spraying made it possible to form a protective Ti-Cu composite coating with anti-corrosion properties on the surface of low-carbon steel. Such Ti-Cu-based coatings can be used not only to protect mechanisms, structural elements and structures operating in mining conditions, but also for their operation in humid climates subject to periodic wetness.

Разработка стандартизированного подхода по выбору пневматических шин на самоходные машины для подземных горных работ

Orientation towards foreign suppliers with their methods and recommendations for tire application on mining machines without taking into account the requirements and specific features of operating conditions in the Russian Federation has led to a lack of domestic regulatory approaches to their use. The article justifies the relevance of developing a standardized approach to selection of giant tires. The development was initiated by “ERT-GROUPP” LLC. Standardization tools are presented, through which the basis for ensuring the quality and efficiency of mine machinery operation will be determined. Provisions of the standardized approach to selection of giant tires for mining machines are developed. An example of tire selection for the Epiroc ST1030 LHD operated in conditions of the Sheregeshskaya mine, EVRAZ ZSMK JSC, is given according to the developed approach to tire selection. The main directions in the industry for application of the standard for the selection of pneumatic tires for underground self-propelled mining machines are given. In conclusion, it is noted that the development of a draft standard for selection of giant tires for mining machines corresponds to the key directions in development of standardization and technical policy to provide the mining industry with modern standardization tools. The use of the national standard entitled “Mining equipment. Self-propelled machines for underground mine workings. The order of selection of pneumatic tires” will contribute to reducing downtime of mining machines associated with the incorrect selection of giant tires depending on the type of machine and the operating conditions, which will reduce economic and material losses of underground mining enterprises.

Increasing the efficiency of ventilation of the Gadir mine

The article is dedicated to the study of effective ventilation of underground mines on the example of the Gadir mine. As is known, the lack of effective ventilation in underground mines makes mining operations difficult and poses a threat to miners’ health. Therefore, it is necessary to pay special attention to the effectiv ventilation of underground mine workings. The Gadir deposit, located in the territory of the Republic of Azerbaijan, is of great strategic importance. Development of the deposit is carried out by the underground method. The article provides brief information about the mine, and describes the methods of ventilation of the mine workings of the Gadir mine. The effect of natural draft on the ventilation of the mine is described, and also the consumption of electricity for ventilation of underground mine workings, and overcoming aerodynamic resistance is calculated. Finally, the results were discussed. It has been determined that a natural draft has a positive effect on ventilation is winter period. Also, it has been determined that the consumption of electricity to overcome the aerodynamic resistance of underground mine workings is insignificant.

Workplace induced heat-related-illness and kidney disorders amongst coal cutters of underground mines

Workers in hot underground coal mines could develop heat-related illnesses, (especially skin, digestion and kidney problems), as compared to workers in non-hot mines. This study found severity of this situation by comparing heat illness symptoms, core body and skin temperature and kidney malfunctioning amongst workers of both types of mines. Ingestible thermometric pills (sending readings to Sensor Electronic Module every 15 s), skin temperature probes (connected to various body parts and sending readings to loggers) and laboratory analysis of pre- and post-shift samples of blood and urine, US-NIOSH-HETA-2012 sheet to survey symptoms, were used to collect data from 50 workers (25 from five hot mines (G1) and 25 from five non-hot mines (G2)). Two mine groups showed significant differences ( p-value &lt;.001) regarding wet-bulb globe temperature, dry-bulb temperature and relative humidity. The highest core body temperature was 38.8°C in G1 and 37.9°C in G2. In intra-group comparison for kidney functioning, post-shift samples showed haematocrit (%) was reduced to 43.6 ± 2.1 from 45.4 ± 1.4 in G1 and to 44.0 ± 2.9 from 45.0 ± 0.75 in G2, and estimated glomerular filtration rate was reduced from 100 ± 19 to 94 ± 0 mL/min/1.72 m2in G1 and to 113 ± 15 from 115 ± 19ain G2 workers. The comparison showed hot mines could induce heat-related illnesses which would necessitate intervention to reduce exposure.

Use of Underground Mining Activities in Earthquake Search and Rescue Works

Although the mining sector has the task of providing raw materials directly or indirectly to industrialestablishments, it unfortunately contains great dangers and risks for its employees in terms of occupational health andsafety. Especially in mining enterprises operating underground, roof collapse, sudden gas discharge, flooding, gasexplosions etc. negativities that occur during production cause great material and moral destruction. In such big problems,well-trained rescue teams of mines play an important role in saving the lives of many miners. Earthquake disastersaffecting 11 provinces in Turkey caused great destruction, many people died in building debris and collapses, andbuildings and industrial facilities were severely damaged on Feb. 6 2023. In the search and rescue works that started afterthe earthquake, the outstanding efforts of the underground mine workers in the field and the methods they used in thesestudies attracted the attention of the public. In this study, evaluations were made by giving some underground rescuemethods used in search and rescue activities in the Adıyaman earthquake region which is one of 11 provinces affectedby the disaster in Turkey.

The specific risks encountered at workplaces in the mines of the Jiu Valley and their correlation with the levels of danger

In order to ensure an appropriate level of security and health in underground mining works, it is necessary to apply some methods of diagnosing the situation of the work system/workplace, from the aspect of work security, which involves: -knowing the risk factors of occupational injury and illness; -the ranking of risk factors in relation to the potential seriousness of the consequences on the executor; -identification and ranking of preventive measures to be applied. The assessment of the risk level is a systematic examination of all aspects of the work process, undertaken in order to eliminate the sources that could cause bodily harm, which constitute the basis for the substantiation of measures to prevent and combat risks. For this reason, all those involved in the work process must be consulted in the risk assessment process. Specific risk monitoring aims to carry out a pre-accident type assessment of the risk of occupational injury and illness using assessment criteria that are based on quantitative risk assessment.

Current status of anxiety and depression disorders among underground coal mining workers in Quang Ninh, 2022-2023

ABSTRACT Background: Describe the current situation of anxiety and depression among underground mining workers at some coal mines in Quang Ninh in 2022-2023. Methods: A cross-sectional survey was conducted on 180 underground coal miners in 02 coal mining companies in Quang Ninh. Research tools are the Zung anxiety scale and the Beck depression scale, which are utilized and evaluated according to the technical regulations of occupational and environmental health. Results: 15% of the study subjects had mental health problems, including 7 people (3.9%) with anxiety disorders and 10 people (5,6%) with depression, 10 people 5.6%) had both mental health problems: anxiety and depression. 8,9% (16 people) have mild anxiety disorder; there was 1 person with severe anxiety disorder. Among the subjects with depression, 15 people (8.3%) had mild depression; 2 subjects had moderate depression and 3 subjects had severe depression through the Beck test. Conclusion: 15% of the total 180 subjects studied, who are laborers working in underground coal miners at two coal mines in Quang Ninh had mental health problems (anxiety and depression), which is a relatively high rate. Larger studies are needed on the mental health status of underground coal miners to identify at-risk groups and related factors for effective early intervention measures. Keywords: coal miners; mental health; anxiety; depression.