Coal spontaneous combustion fires not only waste coal resources, but also restrict underground safety production. Therefore, research on natural prevention and control of coal fires is particularly important for ensuring coal mine safety production. Based on the theory of coal spontaneous combustion and the mechanism of inhibition, the inhibition performance of sodium hypophosphite inhibitors in the process of coal spontaneous combustion oxidation was studied. Firstly, the CO release and inhibition rates of coal samples and inhibited coal samples during the heating and oxidation process were calculated using a programmed heating method. Then, combined with infrared spectroscopy, the influence of hypophosphite on its surface functional groups during coal spontaneous combustion oxidation was studied from a microscopic perspective. Subsequently, thermogravimetric experiments were conducted to analyze the changes in the thermal characteristic curves of inhibited coal samples at different heating rates and particle sizes. Finally, a kinetic model was proposed to analyze the activation energy of the inhibition reaction. Results indicated that the addition of sodium hypophosphite has a natural inhibitory effect on the oxygen absorption and thermal decomposition stages of coal samples.

The study of structural changes and spontaneous combustion characteristics of the coal oxygen composite reaction is the key to preventing coal spontaneous combustion. In this study, gas coal from the 12-2 coal seam of the Donghuantuo Coal Mine was selected for sampling. Various characterization methods were used to conduct elemental analysis on the raw coal and preoxidized coal samples at different degrees as well as surface and internal characteristic analysis on the raw coal and oxidized coal samples to explore the pore distribution of the coal samples and the conversion law of pores with different pore sizes. Simultaneously, the main functional groups and distribution characteristics of different coal samples during low-temperature oxidation were determined, and combined with the analysis of gas products produced by programmed heating, the gas production law and oxygen consumption rate changes were determined by combining the microstructural changes and macroscopic characteristics of coal. The research findings indicate that the pore structure and morphology in coal are greatly affected by temperature, exhibiting a transition from a small number of micropores and a large number of transition pores to medium to large pores in the range of 0-80 °C. The higher the degree of oxidation of coal samples, the lower the content of internal fatty hydrocarbons and the total content of oxygen-containing functional groups. Coal preoxidation shows an exponential rapid increase in CO and CO2 with the continuous increase of temperature. This study provides scientific measures and a theoretical basis for the prevention and control of the coal spontaneous combustion process.

Injection of CO2 into a coal mine goaf is the primary method for inhibiting coal spontaneous combustion and for driving outgas, and gases such as N2, O2, and CH4 in coal are in competition with it, which in turn affects its adsorption effect in coal. In order to enhance the CO2 suppression and expulsion effect, the competitive adsorption characteristics of multicomponent gases in the coal mine goaf were investigated. We carried out adsorption experiments with a specific surface area analyzer to clarify the adsorption law of coal on different gases, conducted CO2 adsorption experiments with an in situ infrared device to reveal the role of functional groups, verified the single-component adsorption law with molecular dynamics simulation, elucidated the effect of temperature on the adsorption of multicomponent gases, and summarized the law of CO2 competition under different pressures. The results showed that the degree of deterioration was negatively correlated with the adsorption capacity, which was N2 < O2 < CH4 ≪ CO2, and the functional group C=O promoted the adsorption of CO2. N2 and O2 adsorption produced only van der Waals force, and CH4 and CO2 promoted electrostatic force, to which CO2 had an obvious advantage of electrostatic potential. In the competition adsorption process, CO2 produces the highest heat of adsorption, and the temperature increase affects the ability to positively correlate with the adsorption capacity of the adsorbate. The adsorption point of carbon dioxide is concentrated near the side branched chain, with better substitution of O2 at P = 1 MPa, while CH4 is mainly rejected at P = 2 MPa. The advantages of injecting CO2 as an inert gas into the air-mining zone were elucidated in terms of functional groups, intermolecular forces, heat of adsorption, and adsorption sites, which provide theoretical support for the suppression of coal spontaneous combustion by replacing O2 and the enhancement of extraction by replacing CH4.

To investigate the problem related to spontaneous combustion of leftover coal in goaf,Donghuantuo gas coal was taken as the model material and pre-oxidizations at 80,160,and 230℃were carried out to study the difference in spontaneous combustion characteristics.In this paper,low-temperature nitrogen adsorption,temperature-programmed gas chromatography and thermogravi-metric(TG)experiments were used to study the pore changes of coal samples at different pre-oxidation temperatures,the changes of characteristic gases and activation energy in the early stage of spontaneous combustion oxidation,based on which the change of spontaneous combustion tendency of coal samples were explored.The results show that the higher the degree of pre-oxidization,the higher the content of macropores and the higher the risk of spontaneous combustion.The main gases are CO,CH4,C2H4 and C2H2 in the programmed temperature test.The initial production temperatures of all kinds of gases rise with the increase of pre-oxidization temperature.Among them,the rate of CO and CH4 gas released by pre-oxidized coal sample has a tendency to surpass that of raw coal.It is found that the characteristic temperature points(T1,T2,T3)of coal sample decrease with the increase of pre-oxidization temperature and the activation energy of coal sample decreases after low temperature oxidation.It is concluded that the spontaneous combustion oxidation capacity of preoxidized coal sample is stronger than that of raw coal.Additionally,the tendency of coal sponta-neous combustion of the coal sample is affected by the structural changes of coal voids and internal energy changes in low temperature oxidization environment.

Initial prevention and control of coal spontaneous combustion has been a hot issue for scientists. The unique advantages of microbes, such as green and low cost, are used to make up for the defects of the traditional coal spontaneous combustion (CSC) control technology. Different microbes within the coal mine environment were isolated, purified, and identified. Different time groups of microbes were cultured in a mixture with coal and structural differences between coal samples were compared. The composition, appearance, and key properties of the coal were characterized through proximate analysis, scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric-mass-infrared spectrometry (TG-MS-FTIR). The results show that all five isolated microbes obviously influence the pore fissures of the coal, and can seal and cover the pores. The moisture and volatile components of the coal with different microbes and time groups are less than those of the raw coal. Microstructural analysis reveals that the degree of coalification and the aromaticity gradually increased with time. The microbes lead to the aliphatic structure to be cleaved. Infrared structural parameters indicate microbes are also influencing oxygen-containing groups. Thermal analysis shows that by using CO2 as an index gas to determine the oxidation stage, it was possible to determine the partial temperature of the microbial inhibition in CSC. The temperature of coal oxidation is delayed by all microbes, with filamentous fungi being the most effective in delaying the temperature. Rhizopus arrhizus can significantly enhance the activation energy. It effectively inhibits the oxidation process of coal, providing a theoretical foundation for microbes to prevent coal spontaneous combustion fires in large-scale mining areas.

Inhibiting oxidative spontaneous combustion of high sulfur coals for green economy and environmental friendliness. Desulphurization using sustainable, low-energy microbiological methods. Gloeophyllum trabeum is selected to lixiviate high sulfur coal. Gloeophyllum trabeum reacts with Fenton reaction in the degradation of cellulose. and its product H2O2 undergoes oxidation-reduction reaction with coal to remove FeS2, to inhibit coal spontaneous combustion. The slurry was reacted by Gloeophyllum trabeum for 30 days, after which it was acid washed and dried, sulfur determination, proximate analysis, X-ray diffraction, Fourier transform infrared spectroscopy, simultaneous TG-DSC apparatus and other experiments. From the macroscopic characteristics and microscopic mechanism, clarify the coal structure and composition variation, after the action of Gloeophyllum trabeum. The results show that the desulfurization rate of the high sulfur coals after the interaction of Gloeophyllum trabeum is above 50%, mainly removing inorganic sulfur, and the volatile matter is decreased after desulfurization. X-ray diffraction results are analyzed by Jade software. The weight percentage of FeS2 decreases from 64.30% to 52.40% and from 57.10% to 45.70% in both coal samples, and the weight percentage of quartz increases by Gloeophyllum trabeum. High-sulfur coals with a sulfur content of 5.02% have an elevated aromatic hydrocarbon content of 2.81% and a decreased oxygenated functional group content of 2.38%; the high sulfur coal with 3.04% sulfur content has an elevated aromatic hydrocarbon content of 3.79%, a decreased oxygenated functional group content of 4.23%, and a decreased aliphatic hydrocarbon content of 1.92%. The characteristic temperature point of the coal is delayed after desulfurization, in which the ignition point T6 of the two coal samples is delayed by 18 ℃ and 32 ℃, and the total heat release of the two coal samples is reduced by 472.66 J/g and 348.19 J/g; The activation energy E in the thermal decomposition stage is increased by 11.79 kJ/mol and 38.67 kJ/mol and finger front factor A become larger, indicating that coal oxidation reactions are difficult to occur after desulfurization with Gloeophyllum trabeum. So it is feasible for Gloeophyllum trabeum to desulfurize and inhibit the coal spontaneous combustion, which provides an experimental foundation for the inhibition of high sulfur coal oxidation.

In order to clarify the adsorption pattern between coal and CO, CO2 and O2, the competition between CO and CO2 and O2 in coal is studied. Qianjiaying bituminous coal is used as the research object, and the molecular unit parameters are calculated by quantitative analysis method based on the experimental results of Fourier transform infrared spectroscopy (FTIR). The molecular cell structure of Qianjiaying bituminous coal is constructed (C1160H860O80N20). To verify the accuracy of the model, the infrared spectrum of molecules is simulated by quantum chemical calculation, and the calculated results are basically consistent with the experimental results. On this basis, the effects of pressure(0−16 MPa) and temperature(20−60 ℃) on the adsorption of CO, CO2 and O2 by coal are investigated by using the Grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) methods. From the experimental results, it can be concluded that the fitted isothermal adsorption curves conformed to the Langmuir equation. Under the same pressure, the adsorption capacity of CO, CO2 and O2 is weaker as the temperature increases. At the same temperature, there is a positive correlation trend between the burial pressure of coal seam and the adsorption amount. The magnitude of adsorption of single gases CO, CO2 and O2 is CO2 > O2 > CO, and CO2 can reach saturation adsorption state in the first. The competitive adsorption results of binary gases show that the adsorption selectivity of CO2/CO has obvious advantages in low-pressure or shallow buried coal seams. However, the adsorption selectivity of O2/CO did not change significantly with the change of pressure. The competitive adsorption capacity of CO2 is greater than that of CO, and the adsorption capacity of CO2 decreases with the increase of CO concentration; The competitive adsorption of O2 is greater than CO when the ratio of CO to O2 molar concentration is ≤ 1, but the adsorption of CO is greater than O2 when the molar concentration of CO is much greater than O2. Therefore, the molar concentration of CO is high, which inhibits the adsorption capacity of CO2 and O2. In other words, in bituminous coal seams with high abnormal CO concentration, the effect of using CO2 injection to control fire extinguishing is not significant, so the amount of air leakage from the working face should also be controlled to prevent CO from desorption to the coal body and to ensure that the CO concentration in the well is within the permissible range.

为明晰不同变质程度煤中微观结构的特殊性和规律性,对3个地区不同煤种的煤进行傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FTIR)技术实验.通过对FTIR谱图的分段分析、分峰拟合和定量计算得出,不同煤阶煤的微观组成有较大差异,并存在官能团百分含量变化.实验结果表明:随着煤变质程度的增加,芳环对应峰数增多,双取代、三取代、五取代均先增加后减少,芳香结构出现变化并存在C—H的断裂和重组;波数在1124～1658 cm-1范围,煤阶越高,吸光度值越小,醇C—OH、C O的百分含量逐渐增大;煤的甲基对称伸缩振动百分含量依次增加,脂肪族次甲基振动百分含量先减小后增大,甲基、亚甲基反对称伸缩振动百分含量均出现先增大后减小的趋势;在波数为3620 cm-1附近处,属于结晶水的游离—O H形成了较弱的氢键,紧密缔合环氢键、OH—O的醚氢键百分含量逐渐减小.煤中基团结构变化属于复杂的煤化过程,可为煤微观组成的探索提供理论和数据依据.

To reveal the CO, CO2, and O2 adsorption properties of two bituminous coals at different pressures and temperatures, the molecular unit-cell structures of two types of bituminous coal are constructed (C1180H960O120N20 and C1160H860O80N20) by Fourier transform infrared (FTIR) spectroscopy. The bituminous coal molecular FTIR spectroscopic curve is calculated by quantum chemistry, and the results are consistent with the experimental curve. The isothermal adsorption curves of the single-component gases CO, CO2, and O2 conform to the Langmuir equation from 20 to 60 °C. The adsorption simulations are mainly performed using grand canonical Monte Carlo (GCMC) methods. The amount of adsorption decreases with increasing temperature at the same pressure, and CO2 can be the first to reach adsorption saturation at the same temperature. The CO2/CO adsorption selectivity for binary gas mixtures has apparent advantages in low-pressure or shallow buried coal seams. The adsorption selectivity of O2/CO varying under different pressures is not obvious. The high amount of CO inhibits the adsorption capacity of CO2 and O2. In other words, the effect of injecting CO2 to control fire extinguishing in bituminous coal seams with high abnormal CO concentrations is not significant.

针对目前钢铁企业生产过程中安全风险特点,提出一种风险评估指标体系建立方法.基于2017～2020年间钢铁企业事故数据并通过查阅相关资料,对所需指标进行初步筛选.运用层次分析法与熵权法2种方法,对指标组合权重进行确定,依照所得权重对初选指标进行筛选,确立钢铁企业安全风险评估指标体系,并对指标体系进行有效性与可行性检验.计算结果表明:该风险评价指标有效性较高,且运用该体系进行风险评估的结果与企业实际相符合.

为改进和提高社区应急管理能力,本文从社区应急准备能力、社区监测预警能力、社区应急决策能力、社区信息沟通能力、社区应急组织能力、社区应急处置能力、社区协调联动能力、社区善后处理能力等8个潜变量,以及28个测量变量构建社区应急管理能力结构方程模型.采用社区应急管理能力调查问卷对社区居民进行调查,问卷包括社区安全文化、社区应急设施、应急安全知识等,通过SPSS24.0对问卷结果进行信效度分析和AMOS21.0进行结构方程检验.结果表明:社区信息沟通能力、社区应急决策能力、社区协调联动能力、社区善后处理能力等对社区应急管理能力有着积极的影响.为此,社区应建立完善的应急决策制度,扩大信息发布渠道,完善信息联动体系,总结危机经验,从而保障居民生活.

Coal is a porous medium. Due to the large number of pores in coal and the pore size on its surface, usually ranging from millimeter to nanometer, it is difficult to measure and analyze the microscopic pore structure of coal. In order to investigate the effect of the microscopic pore structure of coal on its spontaneous combustion tendency, coal samples from different coal mines of the Kailuan Group were selected as the research objects, and the data of the microscopic pore distribution of three different coal samples were measured by using mercury injection apparatus. The regression analysis of microscopic pore data of coal samples obtained in the mercury injection experiment shows that the correlation coefficients of the regression curves are all greater than 0.94 and the fitting degree is good, indicating that there is a good correlation between the pressure, mercury intake and pore size of the coal samples, indicating that the fractal dimension of pore distribution is very effective. The fractal dimension is generally between 2 and 3, indicating that the microscopic pores of coal samples have good fractal characteristics and meet the fractal theory to describe the distribution characteristics of microscopic pores in porous media. Through the simulation system of natural combustion of coal, the simulation experiment of temperature rise oxidation of different coal samples (gas coal, fat coal, and coke coal) was carried out, and the curve of the concentration of gas products CO and CO2 in the process of temperature rise and oxidation of coal samples was drawn in the experiment. The experimental results show the relationship between the distribution structure of coal pores and its spontaneous combustion tendency, and the coal with a good distribution dimension has a stronger combustion tendency.

氧化煤低温自燃会威胁矿井生产和工人生命安全,因此必须对煤自燃的阻燃效果进行研究.在程序升温-气相色谱实验中得到煤自燃氧化过程的产出物,用CO浓度判断氧化煤自燃程度,再比较阻化剂的阻化能力并计算阻化率;利用FTIR绘制特征吸收峰,从微观结构研究阻化机理.实验结果表明:煤自燃的阻燃效果受阻化剂种类和浓度的影响,磷酸三钠阻化效果与其添加浓度呈正相关关系,20％甲基膦酸二甲酯阻化率最高为32.6％,10％磷酸三钠阻化率最低为5.1％;煤分子结构中脂肪烃数量的降低,引起气态烯烃与烷烃产生,从160℃后C-O键开始裂解破坏,导致CO含量剧烈上升,阻化剂的加入能抑制CO的产生,减缓煤氧化速度.

针对煤自燃发火灾害占矿井火灾的 90%以上,严重制约井下安全生产问题,分析了煤自燃机理和煤自燃的发火因子,提出有别于先前煤自燃指标关联关系的判定方法,根据数据挖掘的流程建立了煤自燃影响因素关联规则分析模型,基于数据挖掘 Apriori 算法对煤自燃参数进行结合和关联分析,并计算出支持度为 30%的高频项目组和项集之间的潜在关联,揭示煤自燃发火预警防治的优势,通过Apriori算法进一步提高了煤自燃预测的准确性.

针对化工企业生产中工艺流程复杂、影响因素众多、重特大事故易发的特点,从化工事故发生的多层次影响因素出发,设计构建了化工企业风险评价指标体系,共分为3个一级指标和14个二级指标.基于G1法与物元可拓理论构建了 G1-物元可拓综合评价模型,全面反映化工企业的风险等级水平.运用该模型对唐山某氯碱化工企业进行风险等级评价,计算其各指标权重与关联度,最终得出总目标的风险等级.评价结果与企业实际风险水平基本吻合,表明该方法具有可行性.

为分析煤体结构对煤自燃倾向性的影响及各因素对自燃倾向性的"贡献程度",选取5种不同变质程度的代表性煤样,分别运用程序升温-气相色谱联机装置进行氧化动力学试验测定煤的自燃倾向性综合判定指数;运用扫描电子显微镜、比表面积及孔径分析仪分别进行SEM试验、低温氮气吸附试验对煤的宏观结构进行检测;利用傅里叶红外光谱技术及OMNIC分峰软件进行煤的微观分子主要官能团分析;利用灰色关联分析方法找出各因素与自燃倾向性的关联程度并进行等级划分,并利用SP SS软件及多元统计学原理建立煤自燃倾向性多元回归分析模型并对模型进行检验、各系数分析及正态图分析.结果显示:随着变质程度的增加,主要官能团含量变化明显,大孔及裂隙减少,煤体结构变得紧致,分子稳定性加强,煤自燃倾向性减弱且微孔占比与煤自燃倾向性关联度最大.通过灰色关联分析及煤自燃倾向性的多元回归分析,建立了可靠的煤自燃倾向性的多元回归分析模型,找出了影响自燃倾向性的关键因素,揭示了自燃倾向性与煤部分试验数据的线性关系.

位于唐山市的一所化纤生产企业内粘胶纤维生产线中涉及废气回收工艺,另外二硫化碳(CS2)罐区构成重大危险源.据相关文件及第18个"安全生产月"对于危险化学品安全的大力倡导,对该厂内废气回收一期及二硫化碳罐区危险与可操作性进行分析.选用危险与可操作性分析(HAZOP分析)方法对偏差产生的风险做出了相关说明.结果表明:本次HAZOP分析进一步肯定技术改造过程中的安全防范措施,有利于提高生产线工艺过程以及相关装置的可靠性和安全性;废气回收过程实现了资源的可持续利用.

选取4个不同矿山的煤种制作煤样,通过液氮吸附实验研究煤样孔隙特征,实验测得煤样孔隙比表面积、平均孔径、吸脱附曲线等有关数据.实验结果分析表明:煤样的氮气吸附量与BET比表面积呈正相关,在孔隙结构中,微孔和小孔占煤样孔隙的主要部分,平均孔径越小,10～50 nm的小孔越多,孔容和比表面积两者变化趋势也呈正相关,等温吸附脱附曲线能够判断煤孔隙类型.

为准确预测煤的自燃倾向性,在总结和分析煤自燃倾向性研究现状的基础上,选取煤的组成与结构方面的碳含量、镜质组含量、固定碳含量、比表面积、微孔占比与羟基含量6项主要影响因素建立了基于BP神经网络的煤自燃倾向性预测模型,确立了建模所需的样本,并运用Matlab软件进行网络训练并完成模型检验.将该模型应用于唐山矿9煤层、11煤层及荆各庄矿的煤自燃倾向性预测,结果显示误差均小于5％,证明基于BP神经网络的煤自燃倾向性预测模型的准确度较高,可用于工程实际.

利用易发生自燃反应导致煤矿安全事故的中低变质程度煤进行程序升温-气相色谱联机实验和低温氮气吸附实验,从煤的微观孔隙结构分析煤自燃标志性气体的产出规律.结果表明:中低变质程度煤中,随着变质程度的升高,煤体中大孔减少而中小孔增多,不易气体流通,致使煤自燃标志性气体CO和C2 H4出现的温度点推迟,煤越不易自燃.