Development of Mathematical Models for the Assessment of Fire Risk of Some Indian Coals using Soft Computing Techniques

Coal is the dominant energy source in India and meets 56% of the country’s primary commercial energy supply. In the light of the realization of the supremacy of coal to meet the future energy demands, rapid mechanization of mines is taking place to augment the Indian coal production from 643.75 million tons (MT) per annum in 2014-15 to an expected level of 1086 MT per annum by 2024-25. Most of the coals in India are obtained from low-rank coal seams. Fires have been raging in several coal mines in Indian coalfields. Spontaneous heating of coal is a major problem in the global mining industry. Different researchers have reported that a majority (75%) of these fires owe their origin to spontaneous combustion of coal. Fires, whether surface or underground, pose serious and environmental problems are causing huge loss of coal due to burning and loss of lives, sterilization of coal reserves and environmental pollution on a massive scale. Over the years, the number of active mine fires in India has increased to an alarming 70 locations covering a cumulative area of 17 km2. In Indian coalfield, the fire has engulfed more than 50 million tons of prime coking coal, and about 200 million tons of coals are locked up due to fires. The seriousness of the problem has been realized by the Ministry of Coal, the Ministry of Labour, various statutory agencies and mining companies. The recommendations made in the 10th Conference on Safety in Mine held at New Delhi in 2007 as well as in the Indian Chamber of Commerce (ICC)-2006, New Delhi, it was stated that all the coal mining companies should rank their coal mines on a uniform scale according to their fire risk on scientific basis. This will help the mine planners/engineers to adopt precautionary measures/steps in advance against the occurrence and spread of coal mine fire. Most of the research work carried out in India focused on the assessment of spontaneous combustion liabilities of coals based on limited conventional experimental techniques. The investigators have proposed/established statistical models to establish correlation between various coal parameters, but limited work was done on the development of soft computing techniques to predict the propensity of coal to self-heating that is yet to get due attention. Also, the classifications that have been made earlier are based on limited works which were empirical in nature, without adequate and sound mathematical base. Keeping this in view, an attempt was made in this research work to study forty-nine coal samples of various ranks covering the majority of the Indian coalfields. The experimental/analytical methods that were used to assess the tendencies of coals to spontaneous heating were: proximate analysis, ultimate analysis, petrographic analysis, crossing point temperature, Olpinski index, flammability temperature, wet oxidation potential analysis and differential thermal analysis (DTA). The statistical regression analysis was carried out between the parameters of intrinsic properties and the susceptibility indices and the best-correlated parameters were used as inputs to the soft computing models. Further different ANN models such as Multilayer Perceptron Network (MLP), Functional Link Artificial Neural Network (FLANN) and Radial Basis Function (RBF) were applied for the assessment of fire risk potential of Indian coals. The proposed appropriate ANN fire risk prediction models were designed based on the best-correlated parameters (ultimate analysis) selected as inputs after rigorous statistical analysis. After the successful application of all the proposed ANN models, comparative studies were made based on Mean Magnitude of Relative Error (MMRE) as the performance parameter, model performance curves and Pearson residual boxplots. From the proposed ANN techniques, it was observed that Szb provided better fire risk prediction with RBF model vis-à-vis MLP and FLANN. The results of the proposed RBF network model was closely matching with the field records of the investigated Indian coals and can help the mine management to adopt appropriate strategies and effective action plans in advance to prevent occurrence and spread of fire

Assessment of Spontaneous Heating Susceptibility of Coals Using Wet Oxidation Potential Difference Technique

The main reason behind the spontaneous heating of coal is auto-oxidation. The after effect of spontaneous heating is a major setback in the production of coal.The spontaneous heating depends on many intrinsic factors such as, Ash content, moisture content, volatile matter content and fixed carbon. Apart from all the above mentioned parameters, wet oxidation potential difference method can also be correlated so as to predict its spontaneity for heat. The spontaneous heating susceptibility varies over a large span, thus the experiments become an important tool in predicting the vulnerability to spontaneous heating of a coal sample. In this project, the wet oxidation potential difference experiment was conducted for 20 different coal samples from different mines across India. The coal samples were collected by channel sampling and then they were prepared according to the Indian Standards. The calorific value of all the samples was measured using the Bomb Calorimeter and proximate analysis was also conducted so as to obtain the different parameters about the coal samples such as calorific value, ash, moisture, volatile matter, fixed carbon content. Correlation study was carried out to assess the spontaneous heating susceptibility of coal. In India, generally crossing point method is used for assessment of spontaneous heating susceptibility of coal. However, this method has certain draw backs.The results are dependent upon packing density, rate of heating and oxygen flow rate etc, and sometimes the results are not reproducible. Moreover it takes more than three hours to complete the experiment. Compared to CPT, the wet oxidation experiments only takes about 40 minutes for completion and the results are reproducible. From the correlation analysis, it was found that WOPD indicated a fair measurement of spontaneous heating susceptibility as it showed high correlation with the intrinsic properties such as moisture and volatile matter

Review of experimental methods to determine spontaneous combustion susceptibility of coal – Indian context

This paper presents a critical review of the different techniques developed to investigate the susceptibility of coal to spontaneous combustion and fire. These methods may be sub-classified into the two following areas: (1) Basic coal characterisation studies (chemical constituents) and their influence on spontaneous combustion susceptibility. (2) Test methods to assess the susceptibility of a coal sample to spontaneous combustion. This is followed by a critical literature review that summarises previous research with special emphasis given to Indian coals

Development a modified crossing point temperature (CPTHR) method to assess spontaneous combustion propensity of coal and its chemo-metric analysis

Spontaneous combustion of Indian coals was investigated using spontaneous combustion rig at University of Nottingham, UK to assess their susceptibility. In the present study authors have used eleven coal samples collected from the Jharia coalfield (JCF), India. Both thermal as well as gas profiles from spontaneous combustion rig were studied critically to develop a modified crossing point temperature to assess the spontaneous combustion propensity of coal. The product of combustion gases (CO, CO2, CH4, and H2) emitted from spontaneous combustion rig within the temperature range between ambient and 300 0C of these coal samples were studied. The initial product of combustion gas i.e. CO followed by H2 indicates propensity towards oxidation of coal in laboratory condition for Jharia coalfield. The temperatures at which CO and H2 releases in the level of 50ppm (TCO50, TH250), crossing point temperature of coal (CPTCT) (temperature of coal and bath temperature is same) and modified crossing point temperature of coal (CPTHR) (temperature where dT/dt is equal to 2.0 oCmin-1 because heating rate is double of programme temperature 1 oCmin-1) determined from spontaneous combustion rig categorises the coal as per their propensity to spontaneous combustion. The results of these methods have been compared with other standard method i.e. crossing point temperature method – India, which is widely adopted in Indian regulatory bodies to verify the suitability of this method

Assessment of spontaneous heating of fresh and oxidized coals

Coal oxidation is a natural phenomenon, It may begin in the pit itself or during the operations of extraction, preparation, transportation and storage. A fresh coal is more reactive to oxygen than a weathered coal i.e. it is more liable to spontaneous heating. To see the rate of decrease in the oxidation rate, first coal samples were taken and three samples were prepared from each sample. First sample was same as the sample taken while the second sample was obtained by oxidizing the sample at 200 degree C for 1 day. Third sample was obtained by oxidizing the coal at 200 degree C for 3 day. Then susceptibility of each of these samples were checked by crossing point temperature method, differential thermal analysis and wet oxidation potential method. For the experimentation purpose total of 15 samples were taken. Among these 6 samples were from SECL, 2 samples were from MCL, 2 samples were from CCL, 3 samples were from SCCL. 2 samples were collected from Indonesia to compare it’s characteristics with the Indian coals. The intrinsic property of both the fresh and oxidized coal was determined by proximate analysis. Similarly susceptibility of both fresh and oxidized coal to spontaneous heating was calculated by crossing point temperature and wet oxidation potential.From the experimental results it was found that the volatile matter content of the coal increases as the sample is oxidized while the liability of the coal to spontaneous heating decreases with oxidation. For coals with high fixed carbon content the change in liability of spontaneous heating is significant even after 1 day oxidation. While in case of coals with low fixed carbon content the change in liability of spontaneous heating is not too significant. It is expected that finding of this work will help in deciding whether to adopt any precautionary measures for oxidized coals

XVIII International Coal Preparation Congress

Changes in economic and market conditions of mineral raw materials in recent years have greatly increased demands on the ef fi ciency of mining production. This is certainly true of the coal industry. World coal consumption is growing faster than other types of fuel and in the past year it exceeded 7.6 billion tons. Coal extraction and processing technology are continuously evolving, becoming more economical and environmentally friendly. “ Clean coal ” technology is becoming increasingly popular. Coal chemistry, production of new materials and pharmacology are now added to the traditional use areas — power industry and metallurgy. The leading role in the development of new areas of coal use belongs to preparation technology and advanced coal processing. Hi-tech modern technology and the increasing interna- tional demand for its effectiveness and ef fi ciency put completely new goals for the University. Our main task is to develop a new generation of workforce capacity and research in line with global trends in the development of science and technology to address critical industry issues. Today Russia, like the rest of the world faces rapid and profound changes affecting all spheres of life. The de fi ning feature of modern era has been a rapid development of high technology, intellectual capital being its main asset and resource. The dynamics of scienti fi c and technological development requires acti- vation of University research activities. The University must be a generator of ideas to meet the needs of the economy and national development. Due to the high intellectual potential, University expert mission becomes more and more called for and is capable of providing professional assessment and building science-based predictions in various fi elds. Coal industry, as well as the whole fuel and energy sector of the global economy is growing fast. Global multinational energy companies are less likely to be under state in fl uence and will soon become the main mechanism for the rapid spread of technologies based on new knowledge. Mineral resources will have an even greater impact on the stability of the economies of many countries. Current progress in the technology of coal-based gas synthesis is not just a change in the traditional energy markets, but the emergence of new products of direct consumption, obtained from coal, such as synthetic fuels, chemicals and agrochemical products. All this requires a revision of the value of coal in the modern world economy

Proceedings of the 1st WSEAS International Conference on "Environmental and Geological Science and Engineering (EG'08)"

This book contains the proceedings of the 1st WSEAS International Conference on Environmental and Geological Science and Engineering (EG'08) which was held in Malta, September 11-13, 2008. This conference aims to disseminate the latest research and applications in Renewable Energy, Mineral Resources, Natural Hazards and Risks, Environmental Impact Assessment, Urban and Regional Planning Issues, Remote Sensing and GIS, and other relevant topics and applications. The friendliness and openness of the WSEAS conferences, adds to their ability to grow by constantly attracting young researchers. The WSEAS Conferences attract a large number of well-established and leading researchers in various areas of Science and Engineering as you can see from http://www.wseas.org/reports. Your feedback encourages the society to go ahead as you can see in http://www.worldses.org/feedback.htm The contents of this Book are also published in the CD-ROM Proceedings of the Conference. Both will be sent to the WSEAS collaborating indices after the conference: www.worldses.org/indexes In addition, papers of this book are permanently available to all the scientific community via the WSEAS E-Library. Expanded and enhanced versions of papers published in this conference proceedings are also going to be considered for possible publication in one of the WSEAS journals that participate in the major International Scientific Indices (Elsevier, Scopus, EI, ACM, Compendex, INSPEC, CSA .... see: www.worldses.org/indexes) these papers must be of high-quality (break-through work) and a new round of a very strict review will follow. (No additional fee will be required for the publication of the extended version in a journal). WSEAS has also collaboration with several other international publishers and all these excellent papers of this volume could be further improved, could be extended and could be enhanced for possible additional evaluation in one of the editions of these international publishers. Finally, we cordially thank all the people of WSEAS for their efforts to maintain the high scientific level of conferences, proceedings and journals

Друга міжнародна конференція зі сталого майбутнього: екологічні, технологічні, соціальні та економічні питання (ICSF 2021). Кривий Ріг, Україна, 19-21 травня 2021 року

Second International Conference on Sustainable Futures: Environmental, Technological, Social and Economic Matters (ICSF 2021). Kryvyi Rih, Ukraine, May 19-21, 2021.Друга міжнародна конференція зі сталого майбутнього: екологічні, технологічні, соціальні та економічні питання (ICSF 2021). Кривий Ріг, Україна, 19-21 травня 2021 року

Progress in Landslide Research and Technology, Volume 1 Issue 2, 2022

This open access book provides an overview of the progress in landslide research and technology and is part of a book series of the International Consortium on Landslides (ICL). It gives an overview of recent progress in landslide research and technology for practical applications and the benefit for the society contributing to understanding and reducing landslide disaster risk