煤炭资源是我国基础能源之一，在我国能源需求体系中占据重要地位。煤自燃灾害是影响矿井安全生产的主要灾害之一，而煤与氧气发生物理吸附是煤自燃发生的初始诱因，其中煤氧吸附放热量较小不易被发现且受多种因素影响。因此，本文选取褐煤为研究对象，利用低温氮吸附法、高压吸附仪与微量热仪联用实验法研究了温度、粒度和氧气浓度对煤吸附特性参数的影响；并基于数学分析方法，研究了煤氧吸附特性参数对不同因素的敏感性，构建了多因素耦合作用下煤吸附特性参数的数学表达式。研究结果为进一步揭示煤自燃机理以及研制阻化材料提供了理论基础。

首先，采用全自动比表面积及孔径分析仪对褐煤孔隙结构参数变化进行研究，发现在不同影响因素下煤孔隙结构均以中孔为主；在不同温度、粒度和氧气浓度下，煤比表面积介于8.371~13.748 m²/g、11.464~20.264 m²/g和7.421~13.748 m²/g之间，孔隙体积主要处于0.007~0.009 cm³/g、0.003~0.011 cm³/g和0.005~0.009 cm³/g范围内；确定了煤孔隙结构参数变化规律，阐释了煤比表面积随氧气浓度呈正相关的变化特征，即随氧气浓度的升高，煤分子结构对氧气的吸附作用增强，使得附着于煤分子结构中活性基团的氧气分子增多，导致煤孔壁合并；基于相关性分析确定了影响煤比表面积和孔隙体积的关键因素，即氧气浓度和粒度；采用单因素解析多因素作用的数学方法，建立了多因素耦合作用下煤孔隙结构参数的数学表达式。

其次，利用高压吸附仪和微量热仪联用实验系统对褐煤吸附过程中吸氧量和吸附热的变化进行研究，发现煤氧吸附过程呈阶段性变化特征，即快速吸附、缓慢吸附和逐渐平衡吸附三个阶段；在不同温度、粒度和氧气浓度下，煤吸氧量主要在2.753~3.752 cm³/g、2.864~4.281 cm³/g和2.806~3.685 cm³/g之间，吸附热在3.082~4.001 J/g、2.637~4.715 J/g和3.024~4.001 J/g范围内；确定了煤吸氧量和吸附热的变化规律，揭示了煤吸附热随粒度呈负相关的变化特征，即随粒度的减小，氧气分子附着于煤表面的覆盖度逐渐增大，导致气体分子间的范德华力增强，煤孔隙与被吸附的气体分子间形成势能场，造成氧气分子与煤中活性基团发生碰撞的概率增大，促使煤氧反应性增强；基于相关性分析确定了粒度是影响煤吸附量和吸附热的关键因素；采用单因素解析多因素作用的数学方法，建立了多因素耦合作用下煤吸氧量和吸附热的数学表达式。

最后，基于吸附动力学模型对褐煤吸附过程进行研究，确定了在温度、粒度和氧气浓度下适配度最优的吸附动力学模型，即准一级吸附动力学模型、准二级吸附动力学模型和准一级吸附动力学模型；得到了煤氧吸附速率参数变化规律，阐明了吸附速率参数随氧气浓度呈负相关的变化特征，即随氧气浓度的升高，煤孔壁合并，使得吸附空位减少，导致氧气分子与吸附空位间发生碰撞的概率降低；基于灰色关联性分析确定了氧气浓度是影响煤吸附速率参数的关键因素；采用单因素解析多因素作用的数学方法，建立了多因素耦合作用下吸附速率参数的数学表达式。

The coal resources are one of the basic energy sources and have an important place in the energy demand system of China. Coal spontaneous combustion disaster is one of the main disasters, which affects mine safety production. The physical adsorption between coal and oxygen is the initial inducement of coal spontaneous combustion, among which the oxygen adsorption heat is smaller and not easy to be found and affected by a variety of factors.Therefore, lignite was selected as the research object in this paper. The effects of temperature, particle size and oxygen concentration on the adsorption characteristics parameters of lignite were investigated by using low-temperature nitrogen adsorption method, high pressure adsorption instrument and micro thermal instrument. Based on the mathematical analysis method, the sensitivity of coal oxygen adsorption characteristic parameters to different factors was studied, and constructed the mathematical expression of coal oxygen adsorption characteristic parame-ters under the multi-factor coupling. The study results provide a theoretical basis for further revealing the mechanism of coal spontaneous combustion and developing inhibitory materials.

Firstly, the automatic surface area and pore diameter analyzer was used to study the change of pore structure parameters of coal. It was found that the pore structure of coal is mainly mesopore under different influencing factors. Under different temperature, particle size and oxygen concentration, the specific surface area of coal is mainly between 8.371~13.748 m²/g, 11.464~20.264 m²/g and 7.421~13.748 m²/g. The pore volume is mainly in the range of 0.007~0.009 cm³/g, 0.003~0.011 cm³/g and 0.005~0.009 cm³/g.The law of variation of coal pore structure parameters was determined, and elucidated the characteristic that the specific surface area of coal is positively correlated with oxygen concentration. With the increase of oxygen concentration, the adsorption effect of coal molecular structure on oxygen is enhanced, resulting in the increase of oxygen molecules attached to the active groups in the coal molecular structure, leading to the consolidation of coal pore walls. Based on correlation analysis, it was determined the key factors that affecting the specific surface area and pore volume of coal, namely oxygen concentration and particle size. The mathematical method of single factor analysis and multi-factor interaction was used to establish the mathematical expression of coal pore structure parameters under the effect of multi-factor.

Secondly, the changes of oxygen absorption and adsorption heat during the lignite adsorption process were studied by using the experimental system of high pressure adsorption instrument and micro thermal instrument. It was found the oxygen adsorption process of coal was characterized by stage changes, namely rapid adsorption, slow adsorption and gradual equilibrium adsorption. Under different temperature, particle size and oxygen concentration, oxygen absorption of coal is in the range of 2.753~3.752 cm³/g, 2.864~4.281 cm³/g and 2.806~3.685 cm³/g, respectively. The adsorption heat ranges from 3.082~4.001 J/g, 2.637~4.715 J/g and 3.024~4.001 J/g. The variation patterns of oxygen absorption and adsorption heat of coal was determined, and the change characteristic of coal adsorption heat is negatively correlated with particle size. As particle size decreases, the coverage of oxygen molecules attached to the coal surface gradually increases, leading to the enhancement of van der Waals forces among gas molecules and the formation of potential energy fields between adsorbed gas molecules and coal pores, resulting in an increase in the probability of collision between oxygen molecules and reactive groups in coal, prompting the enhancement of coal oxygen reactivity. The mathematical expressions of adsorption capacity and adsorption heat under multi-factor coupling are establi-shed by using the mathematical method of single factor analysis and multi-factor interaction.

Finally, based on the adsorption kinetics model, it was determined that the adsorption kinetics model with optimal fit under temperature, particle size and oxygen concentration, including the quasi-first-order adsorption kinetics model, the quasi-second-order adsorption kinetics model and the quasi-first-order adsorption kinetics model. The variation law of coal oxygen adsorption rate parameters was obtained, and the negative correlation between adsorption rate parameters and oxygen concentration was elucidated. That is, with the increase of oxygen concentration, the coal pore walls merged, which reduced the adsorption vacancies and resulted in the decrease of the probability of collisions between oxygen molecules and adsorption vacancies. Based on the gray correlation, the oxygen concentration was determined as the key factor affecting the coal adsorption rate parameters.The mathematical expression of the adsorption rate parameters under the multi-factor coupling was established by using the mathematical method of single factor analysis and multi-factor interaction.