CFD Study of Indian Coal to Assess the Severity of Coal Dust Explosion and Its Classification as Per Explosibility Niroj Kumar Mohalik, Asfar Mobin Khan, Santosh Kumar Ray, Debashish Mishra, Jai Krishna Pandey International Journal for Numerical Methods in Fluids, 2026 This paper presents a comprehensive study using computational fluid dynamics (CFD) to evaluate the explosibility of Indian coals and classify their explosion severity. A Siwek 20 L explosion chamber was simulated by ASTM standard 1226‐19 to analyze coal samples collected from 24 coal mines across various coalfields of India. The explosibility parameters that is, maximum explosion pressure (Pmax), maximum rate of pressure rise ((dP/dt)max), explosion delay time (Ted), time to reach Pmax (Tep), and deflagration index (Kst) were estimated for each coal sample to evaluate the deflagration index, which measures the severity of explosions. The deflagration index (Kst) of all coal samples varied significantly between 47.90 bar·ms−1 and 109.43 bar·ms−1 indicating weak explosion potentials (0 < Kst < 200) as per OSHA 2009 standards. Based on this result, a classification system can be proposed for Indian coals depending on shared characteristics, which may be helpful in identifying coal according to their deflagration index (degree of severity). Presently, no formal classification system exists for Indian coal, and current assessments rely on USA OSHA regulations. Hence, multivariate statistical techniques, including feature selection, correlation analysis, multiple regression, and hierarchical clustering, were employed to identify the factors influencing explosion severity and to categorize the coal samples. Volatile matter dry (VMd) and crossing point temperature (CPT) were the most influential factors impacting Kst. A non‐linear regression model yielded a polynomial equation with a strong fit (R2 = 0.909, std. error of estimate = 5.19%) for predicting the deflagration index and validated with test results. Hierarchical clustering further classified the coal samples into three distinct groups based on their explosion susceptibility: highly susceptible, moderately susceptible, and potentially susceptible. The proposed classification and prediction model can guide industry stakeholders to implement more effective explosion mitigation strategies and safety protocols.
Thermal Decomposition Kinetics of Raw and Water Immersed Coal of Raniganj Coalfield Region West Bengal, India Pintu Kumar Mandal, Manoj Kumar Mishra, Niroj Kumar Mohalik International Research Journal of Multidisciplinary Scope, 2025 In this work, coal samples were collected from the Kottadih and Kalimati mines of Raniganj Coalfields (RCF). Kottadih is an underground coal mine and Kalimati is an open-cast coal mine, and the samples were divided into two parts. One part of the samples (raw coal) was analyzed by proximate analysis, Thermal Analysis viz Thermo gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) and spectral Analysis i.e. Fourier Transform Infra-Red spectroscopy (FTIR) and the other part of the samples were immersed in water at a ratio of 1:10 for 15, 30, 90 and 180 days. Spectral and kinetic behaviour of water-immersed coal was also studied. In raw coal and water-immersed coal, the dehydration and desorption reaction occur between 40 and 130 °C. The combustion stage is between 260 and 620 °C and finally burn out or decomposition stages start from 620 to 850 °C, the combustion and burnout stages of water immersed coal decreases. The FT-IR analysis of raw coal shows the presence of –OH, –Ar, –CHO, >C=O, >C=C< etc in small amounts and the concentration of these organic functional groups is comparatively higher in water-immersed coal samples. Due to these results, the propensity for spontaneous combustion/fire increases in both water-immersed coal samples of Kottadih and Kalimati mines of RCF.
THERMAL AND FTIR STUDY OF WATER IMMERSED COAL OF RANIGANJ COALFIELD, WEST BENGAL Pintu Kumar Mandal, Manoj Kumar Mishra, Niroj Kumar Mohalik Niroj Kumar Mohalik Rasayan Journal of Chemistry, 2025 This study investigates the impact of water immersion on the physicochemical properties of coal from two mines within the Raniganj coalfield (RCF). The first sample is taken from Chora Colliery 10 Pit, which is an underground coal mine, and another sample is taken from Dahibadi Basantimata Colliery, which is an open-cast coal mine. Coal samples were subjected to proximate analysis, differential scanning calorimetry (DSC), and Fourier-transform infrared spectroscopy (FTIR). After this, these coal samples were immersed in water in the ratio of 1:10 in the lab environment. These coal samples were taken out after 15, 30, 90, and 180 days and studied by the above method. Proximate analysis revealed a significant increase (30-50%) in moisture and volatile matter content in water-immersed coal compared to raw coal. DSC analysis showed a decrease in ignition temperature of water-immersed coal samples that may increase the risk of spontaneous combustion. FTIR spectroscopy showed that the relative concentration of organic compounds increased in water-immersed coal, which also may favour spontaneous combustion. Volatile matter analysis also confirms the finding of FTIR analysis. These results collectively demonstrate that water immersion significantly enhances the propensity for spontaneous combustion in coal by increasing moisture, volatile matter, and the concentration of reactive organic compounds while lowering the ignition temperature.
Effect of depth and particle size on spontaneous combustion of coal in deep underground mines of Jharia coalfield Debashish Mishra, D.P. Mishra, N K Mohalik, S K Ray, J K Pandey Journal of Sustainable Mining, 2025 Since their inception, the deep mines have faced the challenges of spontaneous heating and fire. The study examines the impact of coal seam depth and particle size on the spontaneous combustion of coal. A spontaneous heating study of seven coal samples shows moisture, volatile matter, and ash do not exhibit any clear trend except for fixed carbon, which shows a direct relationship. However, crossing point temperature (CPT) and thermo-gravimetric (TGignition) temperature reveal an inverse relationship between spontaneous combustion and the depth of the coal seam. Five size ranges: < 106, 106–212, 212–425, 425–2000, and 0–212 µm are studied, which displayed an increase in mean specific surface area (SSA) by 87% and a decrease in mean D90 value by 93%, with a decrease in particle size from 2000 to 106 µm. The reduction in particle size increases the spontaneous heating tendency by nearly 12–14%. The results show that external factors like coal seam depth, particle size, specific surface area (SSA), mining methods, and others influence spontaneous heating and fire in the Jharia coalfield. Additionally, we develop three mathematical models to forecast spontaneous heating in deep underground coal mines, considering CPT, TGignition, particle size (D90), SSA, and coal seam depth.
Optimization of ventilation system for prevention of spontaneous heating/fire during extraction of thick coal seam – A CFD approach Journal of Mines Metals and Fuels, 2019
An investigation to optimise the experimental parameters of differential scanning calorimetry method to predict the susceptibility of coal to spontaneous heating Archives of Mining Sciences, 2010
Role of thermocompositional investigation in early detection of spontaneous heating/fire for safe mining of coal 24th Annual International Pittsburgh Coal Conference 2007 PCC 2007, 2007
Proper sampling of mine gases, analysis and interpretation - A pre-requisite for assessment of sealed off fire area Journal of Mines Metals and Fuels, 2006
Utilisation of industrial wastes for control of slag muck dump fire 22nd Annual International Pittsburgh Coal Conference 2005 PCC 2005, 2005
Application of nitrogen as preventive and controlling subsurface fire - Indian context Journal of Scientific and Industrial Research, 2005
Early detection of occurrences of spontaneous heating in blasting gallery method - A case study Journal of Mines Metals and Fuels, 2004
Information management - The need of modern mining industry Journal of Mines Metals and Fuels, 2003
CFD Study of Indian Coal to Assess the Severity of Coal Dust Explosion and Its Classification as Per Explosibility NK Mohalik, AM Khan, SK Ray, D Mishra, JK Pandey International Journal for Numerical Methods in Fluids 98 (2), 111-137 , 2026 2026 Citations: 1
Methodology in early detection of conveyor belt fire in coal transportation SK Ray, AM Khan, NK Mohalik, D Mishra, NK Varma, JK Pandey, ... Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 47 … , 2025 2025 Citations: 12
Assessment of Spontaneous Combustion Risks Associated with Water-Immersed Coal in the RV Seam of the Raniganj Coalfield West Bengal, India PK Mandal, NK Mohalik, MK Mishra, GC Mondal Journal of Mining and Environment , 2025 2025
Assessing Status of Fire Affected Sealed Panel—A Scientific Approach SK Ray, J Pandey, NK Mohalik, D Mishra, A Kumar, K Anjali, JK Pandey Asian Mining Congress, 907-921 , 2025 2025
Efficient Ventilation System Design for Deep Underground Coal Mines with Multiple Coal Seams Having Goaved Out Areas, Sealed off Areas and Fans NK Mohalik, D Mishra, SK Ray, RK Roy, JK Pandey Asian Mining Congress, 865-875 , 2025 2025
Study the State and Extent of the Fire, Its Rate of Progress in Over Burden Dumping and Surrounding Mining Areas—A Case Study J Pandey, SK Ray, A Khalkho, A Kumar, NK Mohalik, D Mishra, K Anjali, ... Asian Mining Congress, 877-887 , 2025 2025
Development of Dilution Model of Diesel Particulate Matter (DPM) Using Computational Fluid Dynamics (CFD) Modelling for Blind Headings Using Pilot Scale Study D Mishra, SK Ray, NK Mohalik, A Kumar, AM Khan, JK Pandey Asian Mining Congress, 889-898 , 2025 2025
Thermal and Spectral Studies to Assess the Spontaneous Combustion Propensity of Coal Seams of Raniganj Coalfield, India. PK Mandal, MK Mishra, NK Mohalik Journal of Mines, Metals & Fuels 73 (9) , 2025 2025
THERMAL AND FTIR STUDY OF WATER IMMERSED COAL OF RANIGANJ COALFIELD, WEST BENGAL PK Mandal, MK Mishra, NK Mohalik Rasayan Journal of Chemistry 18 (3) , 2025 2025
Reopening and Recovery of Fire Affected Sealed Panels: A Scientific Approach SK Ray, D Mishra, NK Mohalik, J Pandey, AM Khan, A Kumar, JK Pandey Journal of The Institution of Engineers (India): Series D, 1-12 , 2025 2025
Effect of depth and particle size on spontaneous combustion of coal in deep underground mines of Jharia coalfield D Mishra, DP Mishra, NK Mohalik, SK Ray, JK Pandey Journal of Sustainable Mining 24 (1), 117-129 , 2025 2025 Citations: 6
Prediction of Spontaneous Heating Propensity Using Artificial Intelligence and Machine Learning in Deep Underground Coal Mines with Multiseam Workings of Jharia Coalfield D Mishra, N Mohalik, DP Mishra, SK Ray, JK Pandey Available at SSRN 4974747 , 2024 2024 Citations: 1
Fluid Flow Analysis of a Mine Ventilation Axial Fan Using CFD Techniques NK Gokuldas, GM Akshay, MK Shreyas Gowda, KV Deepak, ... Conference on Fluid Mechanics and Fluid Power, 469-481 , 2023 2023
Design of an Effective Ventilation System for Deep Underground Coal Mines Affected by Spontaneous Heating and Fire Using Double Booster Fans–A Practical Approach D Mishra, NK Mohalik, DP Mishra, SK Ray, AM Khan, JK Pandey Asian Mining Congress, 389-400 , 2023 2023 Citations: 1
Experimental and CFD simulation techniques for coal dust explosibility study-A review. AM Khan, SK Ray, NK Mohalik, D Mishra, S Mandal, JK Pandey Mining Engineering 75 (2) , 2023 2023
Multiphase CFD simulation of coal dust dispersion and explosion in a 20 L explosion chamber AM Khan, NK Mohalik, SK Ray, D Mishra, JK Pandey, S Mandal International Conference on Industrial Problems on Machines and Mechanism … , 2022 2022 Citations: 2
Prevention and control of spontaneous combustion/fire in coal stockpiles of power plants using firefighting chemicals NK Mohalik, SK Ray, D Mishra, JK Pandey, S Mondal, AM Khan, ... International Journal of Coal Preparation and Utilization 42 (10), 3173-3184 , 2022 2022 Citations: 10
Improving Workplace Environment of a Deep Underground Coal Mine with Multiseam Workings: An Alternative Approach D Mishra, NK Mohalik, DP Mishra, SK Ray, JK Pandey Mining, Metallurgy & Exploration 39 (4), 1429-1443 , 2022 2022 Citations: 4
Experimental and CFD simulation techniques for coal dust explosibility: a review AM Khan, SK Ray, NK Mohalik, D Mishra, S Mandal, JK Pandey Mining, Metallurgy & Exploration 39 (4), 1445-1463 , 2022 2022 Citations: 16
A comparative kinetic study between TGA & DSC techniques using model-free and model-based analyses to assess spontaneous combustion propensity of Indian coals S Mandal, NK Mohalik, SK Ray, AM Khan, D Mishra, JK Pandey Process Safety and Environmental Protection 159, 1113-1126 , 2022 2022 Citations: 52
MOST CITED SCHOLAR PUBLICATIONS
Investigations of the role of fire retardants in preventing spontaneous heating of coal and controlling coal mine fires, J. Pandey, N. K. Mohalik, D. Kumar, R.K. Mishra, A. Khalkho & V.K. Singh Fire technology , 2012 2012 Citations: 117
Review of preventive and constructive measures for coal mine explosions: An Indian perspective JKP Santosh Kumar Ray, Asfar Mobin Khan, Niroj Kumar Mohalik, Debashish ... International Journal of Mining Science and Technology , 2022 2022 Citations: 91
TGA/DSC study to characterise and classify coal seams conforming to susceptibility towards spontaneous combustion NK Mohalik, S Mandal, SK Ray, AM Khan, D Mishra, JK Pandey International Journal of Mining Science and Technology 32 (1), 75-88 , 2022 2022 Citations: 72
Review of experimental methods to determine spontaneous combustion susceptibility of coal–Indian context NK Mohalik, E Lester, IS Lowndes International Journal of Mining, Reclamation and Environment 31 (5), 301-332 , 2017 2017 Citations: 72
Application of thermal analysis techniques to assess proneness of coal to spontaneous heating: an overview N Mohalik, D Panigrahi, V Singh journal of thermal analysis and calorimetry 98 (2), 507-519 , 2009 2009 Citations: 63
Environmental and socio-economic impacts of fire in Jharia coalfield, Jharkhand, India: an appraisal J Pandey, D Kumar, VK Singh, NK Mohalik Curr. Sci 110 (1639), 1639-1650 , 2016 2016 Citations: 55
A comparative kinetic study between TGA & DSC techniques using model-free and model-based analyses to assess spontaneous combustion propensity of Indian coals S Mandal, NK Mohalik, SK Ray, AM Khan, D Mishra, JK Pandey Process Safety and Environmental Protection 159, 1113-1126 , 2022 2022 Citations: 52
CFD modeling to study the effect of particle size on dispersion in 20l explosion chamber: An overview SK Ray, NK Mohalik, AM Khan, D Mishra, NK Varma, JK Pandey, ... International Journal of Mining Science and Technology 30 (3), 321-327 , 2020 2020 Citations: 46
Development a modified crossing point temperature (CPTHR) method to assess spontaneous combustion propensity of coal and its chemo-metric analysis NK Mohalik, E Lester, IS Lowndes Journal of Loss Prevention in the Process Industries 56, 359-369 , 2018 2018 Citations: 33
Application of TG technique to determine spontaneous heating propensity of coals: NK Mohalik et al. NK Mohalik, E Lester, IS Lowndes Journal of Thermal Analysis and Calorimetry 143 (1), 185-201 , 2021 2021 Citations: 29
Estimation of greenhouse gas emissions from spontaneous combustion/fire of coal in opencast mines–Indian context NK Mohalik, E Lester, IS Lowndes, VK Singh Carbon Management 7 (5-6), 317-332 , 2016 2016 Citations: 28
Application of carbon dioxide (CO2) for controlling subsurface fire area: Indian context N. K. Mohalik, V. K. Singh, and R. V. K. Singh Journal of Mining Science 45 (4), 390-397 , 2009 2009 Citations: 25
Application of Thermography Technique for Assessment and Monitoring of Coal Mine Fire: A Special Reference to Jharia Coal Field, Jharkhand, India J. Pandey, D. Kumar, R.K. Mishra, N. K. Mohalik, A. Khalkho and V.K. Singh International Journal of Advanced Remote Sensing and GIS 2 (1), 138-147 , 2013 2013 Citations: 23
The Application of Nitrogen as Preventive and Controlling Subsurface Fires – Indian Context VKS Mohalik, N. K., R.V.K. Singh, J. Pandey Journal of Scientific and Industrial Research 64 (April), 273-280 , 2005 2005 Citations: 23
Critical appraisal to assess the extent of fire in old abandoned Coal Mine Areas-Indian Context N Mohalik, R Singh, V Singh, D Tripathi University of Wollongong , 2009 2009 Citations: 19
Experimental and CFD simulation techniques for coal dust explosibility: a review AM Khan, SK Ray, NK Mohalik, D Mishra, S Mandal, JK Pandey Mining, Metallurgy & Exploration 39 (4), 1445-1463 , 2022 2022 Citations: 16
An Investigation to Optimise the Experimental Parameters of Differential Scanning Calorimetry Method to Predict the Susceptibility of Coal to Spontaneous Heating Mohalik, N. K., D. C. Panigrahi, V.K. Singh Archives of Mining Science, Vol. 55, 55 (3), 629-649 , 2010 2010 Citations: 16
Assessment of spontaneous heating of coal by differential scanning calorimetric technique-an overview N Mohalik, D Panigrahi, V Singh, R Singh Coal 2009: Coal Operators’ Conference, 303-310 , 2009 2009 Citations: 15
Methodology in early detection of conveyor belt fire in coal transportation SK Ray, AM Khan, NK Mohalik, D Mishra, NK Varma, JK Pandey, ... Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 47 … , 2025 2025 Citations: 12
Prevention and control of spontaneous combustion/fire in coal stockpiles of power plants using firefighting chemicals NK Mohalik, SK Ray, D Mishra, JK Pandey, S Mondal, AM Khan, ... International Journal of Coal Preparation and Utilization 42 (10), 3173-3184 , 2022 2022 Citations: 10
