The Experts below are selected from a list of 9831 Experts worldwide ranked by ideXlab platform
B. Genc - One of the best experts on this subject based on the ideXlab platform.
-
Spontaneous Combustion Liability Indices of Coal
Combustion Science and Technology, 2020Co-Authors: A. R. Gbadamosi, B. Genc, Moshood Onifade, S. RupprechtAbstract:The self-heating of coal due to oxidation potentially leading to its ignition is called “Spontaneous Combustion.” The liability of coal to undergo Spontaneous Combustion for selected coal obtained ...
-
A review of research on Spontaneous Combustion of coal
International journal of mining science and technology, 2020Co-Authors: Moshood Onifade, B. GencAbstract:Abstract Coal oxidation at low temperatures is the heat source liable for the self-heating and Spontaneous Combustion of coal. This phenomenon has imposed severe problems in coal related industries. Attempts to understand this phenomenon by previous researchers have provided significant progress. It is well-known that coal oxidation at low temperatures involves oxygen consumption and formation of gaseous and solid oxidation products. This process is majorly influenced by temperature, oxidation history of coal, coal properties, particle size distribution of the coal, etc. The current understanding of the phenomenon of self-heating and Spontaneous Combustion of coal is discussed along with the different experimental and numerical models established to predict self-heating characteristics of coal. This paper focuses on the global position of the study carried out by academics, research institutes and industries on Spontaneous Combustion of coal and coal mine fires. Within this framework, the generally used Spontaneous Combustion techniques to predict the Spontaneous Combustion liability of coal were evaluated. These techniques are well-known in their usage, but no specific method has become a standard to predict the Spontaneous Combustion liability. Further study is still needed to indicate a number of impending issues and to obtain a more complete understanding on the phenomenon.
-
Spontaneous Combustion liability of coal and coal-shale: a review of prediction methods
International Journal of Coal Science & Technology, 2019Co-Authors: Moshood Onifade, B. GencAbstract:This study presents a review of the various methods to predict the Spontaneous Combustion liability of coal and coal-shale. The relative propensity of coal to undergo self-heating can be established by different methods. These methods are well established in their usage, but the fact that no particular test method has become a standard to predict the Spontaneous Combustion liability indicates that doubt still exists as to the validity of all of them. The underlying principle of all the tests is that the more readily the coal undergoes exothermic oxidation, the more liable it is to self-heat. Comprehensive studies that centres on the international position on research being conducted by academics, different research institutes and industries on Spontaneous Combustion of coal and coal mine fires were evaluated. Relationships between the geochemical analysis (proximate and ultimate analysis, forms of sulphur, petrographic properties, X-ray diffraction and X-ray fluorescence) and Spontaneous Combustion testing methods (numerical and experimental approaches) used to predict the Spontaneous Combustion liability of coal were reviewed. The combination of these tests provides a better understanding of the mechanism that controls the Spontaneous Combustion phenomena. However, irrespective of the extensive studies that have been conducted over time, Spontaneous Combustion is still a major problem in the coal value chain.
-
Spontaneous Combustion of coals and coal shales
International journal of mining science and technology, 2018Co-Authors: Moshood Onifade, B. GencAbstract:Abstract Spontaneous Combustion of coal is a well-known phenomena around the globe. Apart from the coal itself, burning coal-shales is becoming a problem in the South African coal mines. Serious incidents of Spontaneous Combustion have been reported as a result of self-heating of reactive coal-shales. The intrinsic properties and Spontaneous Combustion tests of 28 selected coal and coal-shale samples were conducted and a relationship between the two has been established. Intrinsic properties were obtained by using the proximate and ultimate analysis, and Spontaneous Combustion liability tests results were obtained by using the Wits-Ehac and Wits-CT indices. The experimental results show that intrinsic properties of these materials complement to the Spontaneous Combustion liability tests results. Comparative analyses of intrinsic properties and Spontaneous Combustion characteristics indicate similarities between the mechanism of coal oxidation and that of the oxidative processes undergone by coal-shales. For the tested samples, coal samples have a higher intrinsic Spontaneous Combustion reactivity rating than the coal-shales. Furthermore, an increase in carbon, moisture, hydrogen, volatile matter, nitrogen and a decrease in ash content indicate an increased proneness to self-heating. The concentration of pyrite found in the coal-shales accelerates self-heating. The event of Spontaneous Combustion can occur if coal-shales absorb sufficient oxygen when subjected to atmospheric conditions.
-
Comparative analysis of coal and coal-shale intrinsic factors affecting Spontaneous Combustion
International Journal of Coal Science & Technology, 2018Co-Authors: M. Onifade, B. GencAbstract:Coal and coal-shales tend to undergo Spontaneous Combustion under favourable atmospheric conditions. Spontaneous Combustion liability index and intrinsic properties of coals and coal-shales varies between (above and below) coal seams. The Spontaneous Combustion liability index (obtained from the Wits-Ehac Index) and intrinsic properties (obtained from proximate, ultimate, and petrographic analysis) of fourteen samples representative of in situ coal (bituminous) and fourteen coal-shales obtained in Witbank coalfield, South Africa were experimentally studied. Comparative analysis of the relationships between the Spontaneous Combustion liability index and intrinsic properties of coals and coal-shales were established to evaluate their effects on self-heating potential. The intrinsic properties show linear relationship with Spontaneous Combustion liability and therefore, identifies the factors affecting Spontaneous Combustion of these materials. The influence of coal-shales intrinsic properties towards Spontaneous Combustion liability shows higher correlation coefficients than the coals. Both coals and coal-shales show inertinite maceral as major constituents than the vitrinite and liptinite macerals, hence the reactivity of inertinite macerals may show greater influence on Spontaneous Combustion liability. A definite positive or negative trends exists between the intrinsic properties and Spontaneous Combustion liability index. This research is part of a larger project which is considering the influence of intrinsic properties of coals and coal-shales on Spontaneous Combustion liability.
Moshood Onifade - One of the best experts on this subject based on the ideXlab platform.
-
Spontaneous Combustion Liability Indices of Coal
Combustion Science and Technology, 2020Co-Authors: A. R. Gbadamosi, B. Genc, Moshood Onifade, S. RupprechtAbstract:The self-heating of coal due to oxidation potentially leading to its ignition is called “Spontaneous Combustion.” The liability of coal to undergo Spontaneous Combustion for selected coal obtained ...
-
A review of research on Spontaneous Combustion of coal
International journal of mining science and technology, 2020Co-Authors: Moshood Onifade, B. GencAbstract:Abstract Coal oxidation at low temperatures is the heat source liable for the self-heating and Spontaneous Combustion of coal. This phenomenon has imposed severe problems in coal related industries. Attempts to understand this phenomenon by previous researchers have provided significant progress. It is well-known that coal oxidation at low temperatures involves oxygen consumption and formation of gaseous and solid oxidation products. This process is majorly influenced by temperature, oxidation history of coal, coal properties, particle size distribution of the coal, etc. The current understanding of the phenomenon of self-heating and Spontaneous Combustion of coal is discussed along with the different experimental and numerical models established to predict self-heating characteristics of coal. This paper focuses on the global position of the study carried out by academics, research institutes and industries on Spontaneous Combustion of coal and coal mine fires. Within this framework, the generally used Spontaneous Combustion techniques to predict the Spontaneous Combustion liability of coal were evaluated. These techniques are well-known in their usage, but no specific method has become a standard to predict the Spontaneous Combustion liability. Further study is still needed to indicate a number of impending issues and to obtain a more complete understanding on the phenomenon.
-
Spontaneous Combustion liability of coal and coal-shale: a review of prediction methods
International Journal of Coal Science & Technology, 2019Co-Authors: Moshood Onifade, B. GencAbstract:This study presents a review of the various methods to predict the Spontaneous Combustion liability of coal and coal-shale. The relative propensity of coal to undergo self-heating can be established by different methods. These methods are well established in their usage, but the fact that no particular test method has become a standard to predict the Spontaneous Combustion liability indicates that doubt still exists as to the validity of all of them. The underlying principle of all the tests is that the more readily the coal undergoes exothermic oxidation, the more liable it is to self-heat. Comprehensive studies that centres on the international position on research being conducted by academics, different research institutes and industries on Spontaneous Combustion of coal and coal mine fires were evaluated. Relationships between the geochemical analysis (proximate and ultimate analysis, forms of sulphur, petrographic properties, X-ray diffraction and X-ray fluorescence) and Spontaneous Combustion testing methods (numerical and experimental approaches) used to predict the Spontaneous Combustion liability of coal were reviewed. The combination of these tests provides a better understanding of the mechanism that controls the Spontaneous Combustion phenomena. However, irrespective of the extensive studies that have been conducted over time, Spontaneous Combustion is still a major problem in the coal value chain.
-
Spontaneous Combustion of coals and coal shales
International journal of mining science and technology, 2018Co-Authors: Moshood Onifade, B. GencAbstract:Abstract Spontaneous Combustion of coal is a well-known phenomena around the globe. Apart from the coal itself, burning coal-shales is becoming a problem in the South African coal mines. Serious incidents of Spontaneous Combustion have been reported as a result of self-heating of reactive coal-shales. The intrinsic properties and Spontaneous Combustion tests of 28 selected coal and coal-shale samples were conducted and a relationship between the two has been established. Intrinsic properties were obtained by using the proximate and ultimate analysis, and Spontaneous Combustion liability tests results were obtained by using the Wits-Ehac and Wits-CT indices. The experimental results show that intrinsic properties of these materials complement to the Spontaneous Combustion liability tests results. Comparative analyses of intrinsic properties and Spontaneous Combustion characteristics indicate similarities between the mechanism of coal oxidation and that of the oxidative processes undergone by coal-shales. For the tested samples, coal samples have a higher intrinsic Spontaneous Combustion reactivity rating than the coal-shales. Furthermore, an increase in carbon, moisture, hydrogen, volatile matter, nitrogen and a decrease in ash content indicate an increased proneness to self-heating. The concentration of pyrite found in the coal-shales accelerates self-heating. The event of Spontaneous Combustion can occur if coal-shales absorb sufficient oxygen when subjected to atmospheric conditions.
-
Modelling Spontaneous Combustion liability of carbonaceous materials
International Journal of Coal Science & Technology, 2018Co-Authors: Moshood Onifade, B. GencAbstract:This paper presents predictive models to determine Spontaneous Combustion liability of carbonaceous materials (coals and coal-shales) using statistical analysis. The intrinsic properties and Spontaneous Combustion liability index were determined by testing 14 coals and 14 coal-shales from Witbank coalfields, South Africa. The relationship between these intrinsic properties (obtained from proximate, ultimate and petrographic analysis) and Spontaneous Combustion liability indices (the Wits-Ehac Index and Wits-CT Index) were established. The influence of the intrinsic properties of coal-shales in relation to coal properties affecting Spontaneous Combustion has been established using a statistical method. The linear regression analysis indicates better linear relationships between some of the selected intrinsic properties and Spontaneous Combustion liability index and thus, identifies the major intrinsic factors affecting their liability toward Spontaneous Combustion. It was found that a definite positive or negative correlation coefficient exists between the intrinsic factors and Spontaneous Combustion liability. A set of models to predict the Spontaneous Combustion liability was derived. The best significant correlation along with the most appropriate model as indicated by R-squared values, the coefficient of correlations and standard error was used to predict the incident of Spontaneous Combustion.
Yang Xiao - One of the best experts on this subject based on the ideXlab platform.
-
a random forest approach for predicting coal Spontaneous Combustion
Fuel, 2018Co-Authors: Jun Deng, Yang XiaoAbstract:Abstract The accurate prediction of coal temperature plays a vital role in preventing and controlling the Spontaneous Combustion of coal in coal mines. In this study, a large-scale 2-ton experimental furnace was constructed to implement an oxidation experiment by using a Dafosi coal sample. The aim was to simulate the Spontaneous Combustion of coal at low temperatures (
-
experimental studies of Spontaneous Combustion and anaerobic cooling of coal
Fuel, 2015Co-Authors: Jun Deng, Yang Xiao, Qingwei Li, Junhui LuAbstract:Abstract To study the Spontaneous Combustion and anaerobic cooling of coal, a 15-t experimental furnace was constructed, and large-scale Spontaneous Combustion tests were conducted. The coal sample came from No. 3 seam in Dongtan mine in Yanzhou coalfield, Shandong province, China. The variations in temperature, gas ratios, oxygen consumption rate, and heat intensity were studied. The experimental results show that for coal Spontaneous Combustion below 70 °C, the temperature increases slowly with time and the oxygen consumption rate and heat intensity increase slowly with temperature and accelerate when the temperature exceeds 100 °C. In anaerobic cooling, the cooling rate decreases with the decrease in temperature. When the coal temperature goes from 452.7 to 250.0 °C, the cooling rate decreases rapidly, whereas below 250.0 °C, the cooling rate decreases slowly. The variation trends of the CO 2 /CO, CH 4 /C 2 H 6 , C 2 H 4 /C 2 H 6 , and C 3 H 8 /C 2 H 6 gas ratios in the Spontaneous Combustion and anaerobic cooling of coal in a certain range of temperature can be used to predict the temperature of coal.
Jun Deng - One of the best experts on this subject based on the ideXlab platform.
-
a random forest approach for predicting coal Spontaneous Combustion
Fuel, 2018Co-Authors: Jun Deng, Yang XiaoAbstract:Abstract The accurate prediction of coal temperature plays a vital role in preventing and controlling the Spontaneous Combustion of coal in coal mines. In this study, a large-scale 2-ton experimental furnace was constructed to implement an oxidation experiment by using a Dafosi coal sample. The aim was to simulate the Spontaneous Combustion of coal at low temperatures (
-
experimental studies of Spontaneous Combustion and anaerobic cooling of coal
Fuel, 2015Co-Authors: Jun Deng, Yang Xiao, Qingwei Li, Junhui LuAbstract:Abstract To study the Spontaneous Combustion and anaerobic cooling of coal, a 15-t experimental furnace was constructed, and large-scale Spontaneous Combustion tests were conducted. The coal sample came from No. 3 seam in Dongtan mine in Yanzhou coalfield, Shandong province, China. The variations in temperature, gas ratios, oxygen consumption rate, and heat intensity were studied. The experimental results show that for coal Spontaneous Combustion below 70 °C, the temperature increases slowly with time and the oxygen consumption rate and heat intensity increase slowly with temperature and accelerate when the temperature exceeds 100 °C. In anaerobic cooling, the cooling rate decreases with the decrease in temperature. When the coal temperature goes from 452.7 to 250.0 °C, the cooling rate decreases rapidly, whereas below 250.0 °C, the cooling rate decreases slowly. The variation trends of the CO 2 /CO, CH 4 /C 2 H 6 , C 2 H 4 /C 2 H 6 , and C 3 H 8 /C 2 H 6 gas ratios in the Spontaneous Combustion and anaerobic cooling of coal in a certain range of temperature can be used to predict the temperature of coal.
-
Effects of pyrite on the Spontaneous Combustion of coal
International Journal of Coal Science & Technology, 2015Co-Authors: Jun Deng, Xiaofeng Ma, Yutao Zhang, Yaqing LiAbstract:Pyrite has a significant effect on the Spontaneous Combustion of coal. The presence of pyrite can change the propensity of coal towards Spontaneous Combustion. The influences of various pyrite contents on the parameters of Spontaneous Combustion, such as index gases, temperature and released heat etc., were investigated in this study. Coal samples with different pyrite contents (0 %, 3 %, 5 %, 7 % and 9 %) were made by mixing coal and pyrite. The oxidation experiments under temperature-programmed condition were carried out to test the release rate of gaseous oxidation products at different temperatures. Differential scanning calorimeter (DSC) was employed to measure the intensity of heat release during coal oxidation for various pyrite contents. The results indicate that pyrite can nonlinearly accelerate the process of Spontaneous Combustion. The coal sample with a pyrite content of 5 % has the largest CO release rate and oxygen adsorption as well. However, the coal sample with a pyrite content of 7 % has the largest rate of heat flow according to the results from the DSC tests. Pyrite contents of 5 %–7 % in coal has the most significant effects on Spontaneous Combustion within the range of this study. The conclusions are conducive to the evaluation and control for the Spontaneous Combustion of coal.
Zhang Jia-yong - One of the best experts on this subject based on the ideXlab platform.
-
Spontaneous Combustion Risk Assessment in Coal Seam
Journal of Hebei Institute of Technology, 2020Co-Authors: Zhang Jia-yongAbstract:According to the reasons of Spontaneous Combustion in coal seam,we can build up the factors and framework of the Spontaneous Combustion risk assessment in coal seam,at same time,put up a new way on all-around risk assessment with inexact reasoning.This way can be used not only in the field of Spontaneous Combustion risk assessment in coal seam,but also in simulation before designing.