Mine Fire Research Articles

Infra-red remote sensing inversion technology for hidden fire sources in mine fire areas – joint GSO and PSO algorithms

Mine fires have always been a serious challenge to mining safety, and the existence of hidden fire sources in mine fire areas is one of the key factors causing coal seam spontaneous combustion. Hidden fire source refers to the potential fire source that cannot be easily detected by traditional detection means in the mine. They gradually accumulate heat in the complex environment of the mine. If not detected and dealt with in time, it can lead to a serious mine fire. However, traditional fire detection methods are difficult to detect hidden fire sources in the early stages, and in severe cases, can lead to catastrophic mine fires. Therefore, this study proposes a combined firefly optimisation algorithm and particle swarm optimisation algorithm for infra-red remote sensing inversion of hidden fire sources in mine fire areas, and verifies it. The results indicated that the inversion model could accurately obtain the location and intensity information of hidden fire sources. The joint algorithm exhibited higher accuracy and faster convergence speed during the training process, with an accuracy of 97.64% and an average temperature error of only 0.73°C. The average accuracy of the inversion model optimised by the joint algorithm improved to 99.48%, the average calculation time reduced to 7.25 seconds, and the efficiency has been improved by 51.92%. This study innovatively combines infra-red remote sensing inversion technology with intelligent algorithms to improve the efficiency and accuracy of detecting hidden fire sources in mine fire areas, which helps to reduce safety risks and economic losses caused by mine fires.

Respiratory symptoms after coalmine fire and pandemic: A longitudinal analysis of the Hazelwood Health Study adult cohort.

The aim of this study was to determine whether the effects of extreme but discrete PM2.5 exposure from a coal mine fire on respiratory symptoms abated, persisted, or worsened over time, and whether they were exacerbated by COVID-19. We analysed longitudinal survey data from a cohort residing near a 2014 coalmine fire in regional Australia. A 2016/2017 survey included 4,056 participants, of whom 612 were followed-up in 2022. Items included respiratory symptoms, history of COVID-19, and time-location diaries from the mine fire period, which were combined with geospatial and temporal models of fire-related PM2.5. Longitudinal effects of fire-related PM2.5 were examined using a mixed-effects logistic regression model. Exacerbation due to COVID-19 was examined using a logistic regression model. PM2.5 exposure was associated with chronic cough and possibly current wheeze, chest tightness, and current nasal symptoms 2-3 years post-fire, and chronic cough and current wheeze 8.5-9 years post-fire. Further, the association between PM2.5 and chronic cough and possibly current wheeze appeared to increase between the survey periods. While there were no detectable interactions between PM2.5 and COVID-19, PM2.5 exposure was associated with additional respiratory symptoms among participants who reported a history of COVID-19. In summary, medium-duration exposure to extreme levels of fire-related PM2.5 may have increased the long-term risk of chronic cough and current wheeze. While the COVID-19 pandemic started several years after the mine fire, contracting this illness may have exacerbated the effect of fire-related PM2.5 through development of additional respiratory symptoms.

Mechanical response characteristics and cushioning of sealed airbags under different length–diameter ratios

In the event of a mine fire, rapidly constructing blast-resistant seals is one of the most effective measures to contain the disaster. This study conducted blast cushioning experiments on sealed airbags and numerical simulations by analysis system/Livermore software-dynamics (ANSYS/LS-DYNA), an explicit simulation software, to analyze the mechanical response characteristics and cushioning effectiveness of sealed airbags under different length-to-diameter ratios. The research results indicate that airbags with different length-to-diameter ratios all exhibit cushioning effects, and the airbag can recover its deformation after pressure release. As airbag length increases, vertical deformation along the pipeline appears, forming a radial compression failure mode. Stress concentrations are mostly located at the edges of the airbag, while arched structures can reduce the concentrated stress. Excessively long or short airbags significantly increase localized stress concentrations. The total energy absorbed by the airbag during cushioning shows a linear relationship with its length, and an energy absorption model for single-chamber airbags with varying length-to-diameter ratios was established. Under full-scale simulation conditions, the optimal length-to-diameter ratio range is 0.75:1. The reflected energy of shockwave encountering airbag is independent of airbag length and remains a fixed value when inflation pressure remains constant. These findings provide theoretical support for the design and application of explosion-resistant airbag.

Similar pipeline experiment and disaster control emergency plan of updraft airflow fire in mine

Based on the engineering example of Linsheng coal mine, this paper uses TF1M3D computer simulation platform to systematically analyze the process of smoke flow spreading and air flow disorder disaster from the perspective of the whole mine network, and puts forward corresponding plans and measures. A small scale similar experiment was carried out to study the updraft flow fire in the mine. Through the analysis of the collected experimental data, the variation law of the air volume of the fire source in the main air path, side branch road and total air path with different air volume and the variation characteristics of the temperature at the monitoring point with time were obtained under different air volume conditions, and the critical air volume was fitted as 1.65 m3·s− 1. The CAD digital stereoscopic model of Linsheng mine was established, and the TF1M3D simulation platform was used to simulate the mine fire under normal ventilation condition. The preset fire source point of the conveyor belt roadway in the first west district of Linsheng coal mine was used to observe the change of air volume during the fire process.The smoke flow reversal phenomenon would occur when the fire occurred in the first west district. The reversed smoke flow will flow to the 503 face and cause contamination. In order to inhibit the reversal of smoke flow, the emergency plan is proposed to increase the number of fan rotation and set fire doors in appropriate places, which can effectively inhibit the diffusion of smoke and improve mine disaster resistance.

Investigating the Aracoma Alma Mine Fire and SOMA Mine Disaster with the Causal Analysis based on Systems Theory: A Comparative study

Investigating the Aracoma Alma Mine Fire and SOMA Mine Disaster with the Causal Analysis based on Systems Theory: A Comparative study

Research on smoke diffusion and evacuation routes of mine fires with complex roadway networks

Research on smoke diffusion and evacuation routes of mine fires with complex roadway networks

Study on Emergency Decision-Making of Mine External Fires Based on Deduction of Precursory Scenarios

External mine fires are known for their unpredictability, rapid spread, and difficulty in terms of extinguishment, often resulting in severe casualties and property damage when not managed swiftly. This study examines the progression of coal mine fire incidents through scenario deduction and presents an emergency decision-making model based on precursor scenario analysis. We classify precursor elements according to the causes of coal mine fires, organizing scenario elements into states, precursors, and emergency activities using knowledge meta-theory. A dynamic Bayesian network forms the core of the decision-making model, enabling calculation of scenario node probabilities and the development of expert-driven response strategies for critical scenarios. Additionally, we design a comprehensive evaluation index system, utilizing multi-attribute decision-making to establish decision matrices and attribute weights. An improved entropy-weighting TOPSIS method is used to select the optimal emergency decision scheme. The model’s effectiveness is demonstrated through a case study of the “9–27” fire incident at the Chongqing Songzao Coal Mine, where findings affirm the model’s practicality and accuracy in supporting timely, effective emergency responses to external coal mine fires.

Coupled Neural Networks and Genetic Algorithms Application in the Field of Mine Fire Extinguishing

Coupled Neural Networks and Genetic Algorithms Application in the Field of Mine Fire Extinguishing

Identification and Ranking of Factors Affecting the Emission of CO Gas in Karkar Coal Mine

Karkar coal mine is one of the biggest mines in the country, where mining has been going on since 1938. During the mining period, the Karkar mine has witnessed unfortunate incidents caused by the release and explosion of gases, which have caused substantial financial and human losses. Carbon monoxide gas is one of the essential factors in the occurrence of accidents in the Karkar mine. This research includes literature reviews, field data collection using the CEM CO-181 model gas meter, and statistical calculations using Shannon entropy and Promethee methods. First, the concentration of CO gas was measured in ventilation tunnels, development, and excavation areas. Extraction workshops of the Karkar coal mine at different working times, and then 26 cases that may result in a reduction in accidents were used as effective criteria, and 9 cases were used as influential factors on CO emissions through the order and distribution of questionnaires and interviews with identified experts. The final weights of twenty-six effective criteria on the emission of CO gas were calculated based on the Shannon entropy method. As a result, the criterion of consumed oils with a final weight of 0.1790 was ranked first, and the criterion of lack of experience with a final weight of 0.1065 was ranked last. The influential factors have been ranked based on the amount of net flow and the parameter method. As a result, the factors of mining fire and coal dust explosion ranked first and last, respectively, with net flows of 0.55 and -0.84, and the rest of the factors are placed in different positions according to their net flow rate and have their effects on the emission of CO gas.

Geo-sustainability Challenges and Remediation Strategies: A GIS-based Assessment of Sripur Coalmine Areas, West Bengal, India

This study examines the health, risk, and safety aspects of coal mining in the Sripur area, focusing on the Bhanora West Block, Asansol, West Bengal, India as one of the 14 operational mines of Eastern Coalfields Limited in Asansol. The study addresses the increasing risks of accidents, fires, and subsidence in active, ageing, and closed mines and storage yards. The study’s incorporation of field surveys, satellite imagery, and environmental data ensures that the findings are based on a well-rounded and multi-faceted dataset. The satellite imagery data (GIS and Remote Sensing) are perceived along with available literature and environmental impact compliance reports from time to time, with particular interest in the Bhanora West coal mine, both open cast and underground. The aspect, Hill shade, LULC and stream order maps of the Damodar are generated using Q-GIS, 3.28.7. The environmental clearance data, accident data, subsidence area, and landslide data are analysed. A vast area in Sripur is observed to be under subsidence, with cracks appearing even near residential areas. The flow of the Nunia nallah is nearby, and old closed mines are not adequately backfilled, so the chance of seepage cannot be neglected though regularly attended. Pneumoconiosis (CWP), a lung disease (black lung), chronic obstructive pulmonary disease (COPD), and silicosis are common in Sripur due to dust and substandard water. Effective and riskless mining extractions using proper technologies can avoid mining hazards, such as subsidence, the influx of water in underground mines, health hazards, air/water pollution, mine fire, and intact physical landscape and observing criteria of sustainable Development Goal SDG-1 SDG-3, SDG-6, SDG 12, SDG-13, and SDG 16.

The status of artisanal coal mining in Afghanistan: Using remote sensing to assess remaining artisanally mineable Jurassic coal resources

Coal mining is critical to the functioning of the current Afghan economy providing jobs, tax revenue, and foreign exchange. Taxes on coal may constitute the Taliban Government’s single largest source of operating income. Prior to the start of mining, Afghanistan had between 215 M and 430 M tonnes of hypothetical category Jurassic coal resources at depths accessible to artisanal miners. Since 1940, between 51 M and 89 M tonnes of coal have been extracted. Technologically primitive mining practices result in suboptimal coal extraction from disorganized room and pillar mines leaving significant amounts of coal unmineable. Frequent tunnel collapse, gas and coal dust explosions, and uncontrolled widespread mine fires have destroyed or made inaccessible significant additional volumes of remaining artisanally mineable resources. The haphazard unmapped development of the existing Jurassic coal makes it impossible to redevelop these fields using more efficient mining technologies. If new mines are to be developed, they will have to tap subsurface coals not accessible to artisanal miners. 66 % of the area mapped as Lower to Middle Jurassic rock does not host outcropping coal beds. This area, as well as some of the areas beneath thin veneers of lowest Cretaceous sediment are potential exploration targets. Jurassic coals are very gassy. Developing coalbed methane prospects is a more effective and less environmentally destructive means to access the energy contained in the Jurassic coals.

The Sheltering Effect of A Cuddy During A Fire in an Underground Mine

The Sheltering Effect of A Cuddy During A Fire in an Underground Mine

Cancer incidence after an open cut coal mine fire

Using population-level cancer diagnosis data, we compared cancer incidence in locations affected by smoke from a six week-long open cut coal mine fire in regional Victoria, Australia, up to seven years following the event. There was no detectable effect on cancer incidence overall. While several subgroups exhibited changes, these were more likely due to statistical chance rather than real effects. These findings may be limited by low statistical power and short duration of follow up. To confirm the influence of open cut coal mine fires on cancer incidence, further research and an extended follow-up duration are necessary.

Particle swarm optimization inverse tracing method for mine tunnel fire based on quasi-steady-state heat transfer mechanism

Rapidly locating and assessing fires in coal mines is essential for effective response and minimizing damage. Traditional methods often struggle to swiftly and accurately pinpoint fire locations and statuses. Hence, this study introduces a particle swarm inverse tracing approach based on the quasi-steady-state heat transfer between high-temperature flue gases and mine tunnel walls. This method aims to remotely monitor smoke flow temperatures and gas concentrations to determine fire locations and combustion trends. Validation of the fire source tracing model was conducted through comprehensive tunnel fire experiments and numerical simulations. The particle swarm optimization inverse tracing method yielded a maximum 7.65 % error in fire location determination compared to actual measurements, while accurately matching the measured fire source heat release rate curve. These findings underscore the method’s high precision and reliability, particularly evident during the developmental and stable stages of fire burning.

Multi-Objective Real-Time Planning of Evacuation Routes for Underground Mine Fires

When a fire occurs underground, pre-existing emergency escape routes may become ineffective. Such scenarios necessitate the real-time planning of escape routes that consider evolving conditions and prioritize safety. This paper proposes a multi-objective real-time search method for emergency escape routes using dynamic programming to address these challenges. Firstly, this paper discusses how the evacuation of an underground mine fire caused by external factors depends on the fire monitoring system, personnel positioning system, and emergency evacuation system, as well as the modeling and solution methods of evacuation route planning. Then, based on fire smoke, CO, and temperature sensor data from the mine ventilation network structure and monitoring system, the possible smoke spread in the event of an underground fire was calculated. The objectives are to optimize both the shortest equivalent length of the path and the shortest time to walk through the smoke flow while ensuring that temporary escape time does not exceed the rated protection time of the self-rescuer. A mathematical model for emergency escape route planning is established under these conditions. A labeling algorithm based on dynamic programming is employed to find the Pareto optimal solution set of emergency evacuation routes that meet emergency requirements. Finally, two path evaluation indicators, namely “escape target priority” and “personnel temporary escape time”, are introduced to re-rank the solutions in the Pareto optimal set, thereby obtaining disaster evacuation routes with different priorities. Example verification shows that the algorithm can quickly solve the disaster evacuation routes that meet the actual disaster evacuation needs in complex networks. Example verification shows that the algorithm can quickly solve the emergency escape routes in complex networks that meet actual emergency escape needs.

A Novel Microbial Compound Inhibitor and Its Efficacy in Preventing and Controlling Mine Fire Risks: A Case Study on Low-Rank Coal Spontaneous Combustion.

To guarantee the safety and sustainability of coal mining by effectively mitigating the substantial risk associated with coal spontaneous combustion, this study proposes a multifaceted prevention strategy aligned with green environmental principles. A compound flame retardant with a physicochemical control mechanism was prepared using indigenous microorganisms to mineralize residual coal after mining, utilizing Bacillus pasteurelli as a substitute material for inorganic salts. Under laboratory conditions simulating coal self-combustion, biobased flame retardants were employed to investigate the physical and chemical transformations of heat and mass evolution from ambient temperature to combustion in two representative low-rank coals. By quantitatively comparing alterations in microbiome-based groups among raw lignite, bioretarded lignite, and two control samples, the inhibitory mechanism of biobased materials on the oxygen reaction pathway was elucidated. The findings substantiated that biobased modification can consolidate the methyl and methylene groups present in aliphatic hydrocarbon side chains, which are prone to instigating low-temperature oxidation reactions. Additionally, the preventive performance of biobased flame retardants was assessed through temperature-programmed experiments, which involved estimating the critical self-heating temperature, oxygen consumption, and gas production rates of compared coal samples. The results demonstrated significant enhancements in the resistance to spontaneous combustion following bioretarded modification. Notably, the identification grade of long flame coal shifted from easy to moderate susceptibility to spontaneous combustion. Furthermore, biobased flame retardants exhibited remarkable flame retardancy rates of approximately 80% for lignite, thereby validating their efficacy as more environmentally friendly and technologically advanced substitute materials for inhibiting spontaneous combustion in low-rank coals.

Long-term effects of a coalmine fire on hospital and ambulance use: An interrupted time series study

BackgroundIn 2014, the Hazelwood coalmine fire in regional Victoria, Australia shrouded nearby communities in smoke for six weeks. Prior investigations identified substantial adverse effects, including increases in the use of health services. In this study, we examined the effects on hospital and ambulance use in the eight years following the fire. MethodsUsing Victorian hospital (Jan 2009–Jun 2022) and ambulance (Jan 2013–Dec 2021) data, we conducted an interrupted time series of changes to the rate of hospital admissions, emergency presentations, and ambulance attendances. A categorical exposure model compared two locations, most-exposed Morwell and less-exposed Latrobe Valley, to the rest of regional Victoria. A continuous exposure model used spatial estimates of fire-related PM2.5. Analyses were stratified by sex, age group (<65/65+ years), and condition (cardiovascular, respiratory, mental health, injury). ResultsThere were small but significant increases in overall hospital admissions and emergency presentations across all analyses, but little evidence of change in overall ambulance attendances. Effects varied considerably by condition, with the biggest relative increases observed among hospital admissions for mental health conditions and injuries. While cardiovascular-related hospital admissions and emergency presentations increased post-fire, ambulance attendances decreased. ConclusionsOur findings suggest the Hazelwood coalmine fire likely increased hospital usage. However, it is unclear whether this was due to the direct effects of smoke exposure on health, or the disruptive socioeconomic and behavioural impacts of an environmental disaster that affected how communities engaged with various health services.

Simulation study on the spread characteristics of fires and control measures in high-inclination belt conveyors

Understanding the behavior of high-temperature smoke propagation in roadways during coal mine fires and evaluating control measures are crucial for enhancing safety. This study, based on a significant fire incident at Chongqing Songzao Coal Mine, utilized PyroSim software to model the affected roadway. The laws governing smoke propagation and changes in temperature and CO concentration after fires were simulated and analyzed. Furthermore, the efficacy of combined reverse wind and water spray measures in mitigating the adverse effects of smoke spread was examined. The results indicated that smoke emanated from the fire source and spreads with airflow to the 2# coal bunker of the machine head, bifurcating into left and right paths. Downstream monitoring points exhibited decreasing temperatures with increasing distance from the fire source, while the initial detection time of CO gas increased correspondingly. The combined measures of reverse wind and water spray effectively mitigated smoke reverse spread. Compared to using reverse wind alone, these measures reduced temperatures by 17 °C at the nearest A5 monitoring point to the fire source and reduced CO concentrations by 5200 ppm.

Experiments on a Mine System Subjected to Ascensional Airflow Fire and Countermeasures for Mine Fire Control

The disorder and disaster evolution characteristics of ascensional airflow fires in mine ventilation systems has been the focus of mine fire research. In this work, through repeated experiments, the variation characteristics of the temperature and air volume in the main and side branches of an ascensional airflow fire were obtained under different ventilation capacities. Using the TF1M(3D) software to solve the problems of mine physical ventilation and combined with the analysis of an example, the variation in the ascensional airflow fire and the process of disordered airflow in the ventilation system in an entire area mine were described in detail. Fire combustion served as the power source for uncontrolled energy release, and its fire pressure interacted with the thermal resistance of the mine ventilation, directly causing airflow disorder. As the fire intensified, the ascensional airflow fire caused the airflow in the side branch to decrease, stagnate, or reverse. Improving the fan supply capacity can not only help reduce the increase in the ventilation thermal resistance of the side branch but also help avoid the airflow reversal of the side branch. From the regular variation characteristics, the theoretical results were found to be in good agreement with the experimental results.

Analysis of stage parameters of low-temperature oxidation of water-soaked coal based on kinetic principles

Mine fires caused by spontaneous coal combustion are major disasters in coal mines. The staged oxidation kinetic parameters of various coal samples at oxygen concentrations of 21 %, 15 %, 10 %, 5 %, and 3 % were analyzed using a programmed temperature testing system. Herein, the temperature increase rate of coal, the temperature difference between the furnace and coal, and the oxygen consumption characteristics were obtained. Based on the amount of CO produced and the temperature sensitivity coefficient, three characteristic temperatures and four stages of low-temperature oxidation (LTO) were identified. The results showed that at a critical temperature (TC), the amount of CO gas released from the coal samples increased with increasing oxygen concentration, and the difference in the oxygen consumption rate increased. After the limit temperature (Tu), the amount of CO gas increased steadily, and the increase in the oxygen consumption rate stagnated. CO production, the maximum heating rate, and the maximum heat release rate were positively correlated with the oxygen concentration. As the oxygen concentration increased, the activation energy during the oxygen absorption stage gradually decreased. The average reaction enthalpy (ΔH) of pre-oxidized water-immersed coal was 19.37 kJ/kg greater than that of raw coal. The equation for the conservation of energy of the coal oxidation warming process was normalized. The theoretical values of the awakening stage and the stable stage were τν and τν (1-B), respectively. When B was >1, pre-oxidized water-immersed coal at a low oxygen concentration was prone to crossover points during the oxygen absorption stage, which increased the risk of coal spontaneous combustion (CSC). The research results could provide a theoretical basis for the staged control of the spontaneous combustion of water-immersed coal in goaf areas.