Experimental Study On Spontaneous Combustion Characteristics Of High Sulfur Anthracite In Yangmei No.5 Coal Mine

Yangmei No.5 Coal Mine is a highly sulfur and highly metamorphic anthracite,and it is traditionally believed that the active side chain and oxygen-containing functional groups in its molecular structure are reduced or even disappeared,and the degree of aromatization is high,so it has strong antioxidant effect and is difficult to spontaneously combust.However,because the coal contains sulfur,the spontaneous combustion and ignition problem during the recovery process of the working face are serious,so it is of great significance to study the spontaneous combustion characteristics and influence mechanism of anthracite with high sulfur content.In this paper,the influence of different sulfur content on coal spontaneous combustion is studied by combining theoretical analysis and experimental research,and the experimental coal samples are made by mixing anthracite with in-situ flotation pyrite with different content,and the influence of sulfur content on anthracite functional groups,oxidation process gas products,characteristic temperature and thermal effects is studied,and the mechanism of spontaneous combustion of anthracite with high sulfur content is further obtained.Through infrared spectroscopy experiments on coal samples with different pyrite contents,it is concluded that in the process of coal oxidation,the peak intensity of aliphatic hydrocarbons（-CH₃antisymmetric stretching,-CH₂ symmetric stretching）and C-O-C stretching vibration gradually decreases with the increase of pyrite content.The benzene ring skeleton and hydroxyl increased first and then decreased with the increase of pyrite.When the added pyrite content is9.97%,the peak intensity of the coal sample changes the most.Through the experimental study of low temperature oxidation characteristics of coal,it is concluded that when the temperature is constant,the gas release amount,CO and CO₂gas production rate,oxygen consumption rate and heat release intensity in the process of coal spontaneous combustion increase first and then decrease with the increase of sulfur content.The apparent activation energy and the critical temperature of spontaneous combustion decrease first and then increase with the increase of sulfur content.And reached the extreme point when the pyrite content was 9.97%.When the pyrite content is constant,the gas release,gas production rate（CO and CO₂）,oxygen consumption rate and heat release intensity of coal spontaneous combustion change exponentially with temperature.Through the experimental study of coal thermal effect,it is concluded that in the whole oxidation process of coal samples,the heat release of coal samples increases first and then decreases with the increase of pyrite content.The total heat release of the original coal sample is slightly higher than that of the coal sample with 9.97%pyrite,but the difference between the two is very small and almost negligible.Combined with the results of temperature programmed test,the total heat release of coal samples at critical temperature and dry cracking temperature can be concluded that the heat release of coal samples increases first and then decreases with the increase of pyrite content,and reaches the maximum point when pyrite content is 9.97%.Through the experimental study of coal thermal effect,it is concluded that the heat release of coal sample changes with the increase of sulfur content in the whole oxidation process.Combined with the results of the temperature programmed experiment,the change of the heat release intensity of the coal sample at the critical temperature and the dry cracking temperature is obtained.H₂C=CH₂ out-of-plane rocking functional group as auxiliary spontaneous combustion functional group of coal sample,methyl and methylene consumption in aliphatic hydrocarbon also generated ether bonds,sulfur content increased to promote ether bonds,H₂C=CH₂ out-of-plane rocking formation,the more likely the coal sample is to spontaneous combustion.The research results provide theoretical support and technical support for the prediction and prediction of fire in Yangmei Minmetals mine,which is of great significance for mine disaster management and ensuring mine safety production.The paper has 44 pictures,25 tables,and 155 references.