基于微观分子结构特性的煤尘润湿机理基础研究

This project is put forward to solve the problems of bad wettability, unintelligible microscopic wetting mechanism, poor dedusting effects in most of coal seams in China. Firstly, the conditions of dust's contact angle, settling time and positive-reverse direction permeability of the 14 representative coals in China will be tested, the diffusion law of the coal dust wettability in different coal mines can be found out. Then, the physical and chemical structures of different kinds of coal dust will be tested and analyzed comprehensively by using modern testing techniques, such as SEM, FTIR, XRD, XPS, NMR and so on. The particle parameter fractal dimensions of the coal dust will be calculated, at the same time, the microscopic characteristics of the coal dust, for example, the functional groups, surface elements, chemical states, phase components, crystallite parameters, carbon structure parameters, pore distribution and so on can be achieved. Furthermore, the experimental data will be analyzed by the tools of rough set and neural network, extracting the important indicator that impacts coal dust wetting ability. Fitting coupling relations of multiple parameters between coal dust wetting characteristics and physical and chemical characteristics by numerical analysis software, the law of coal dust microscopic characteristics affecting its wettability can be acquired. Finally, the coal dust wetting mechanism will be studied based on the gas-solid-liquid three phase surface and interface chemistry basic theory, then the coal dust wettability evaluation system and wetting dynamic model will be proposed. All these above will provide theoretical bases for realizing prevention and control of the difficult wetting coal dust essentially.

本项目是针对我国大部分煤层的煤尘润湿性差、微观润湿机理不清晰、降尘效果不佳等问题提出的。首先，对我国14类代表性煤种煤尘的接触角、沉降时间和正反向渗透情况进行测定，摸清全国不同矿区煤尘润湿性分布规律；其次，利用SEM、FTIR、XRD、XPS、NMR等现代测试技术对不同煤种煤尘的微观理化结构进行全面试验分析，计算得出煤尘颗粒参数分形维数，同时得到煤尘的官能团、表面元素、化学状态、物相成分、微晶参数、碳结构参数、孔隙分布等微观特性；再则，通过粗糙集、神经网络等工具对试验数据进行统计分析，提取影响煤尘润湿能力的重要指标，并利用数值分析软件拟合煤尘润湿特性、理化特征多元参数之间的耦合关系式，确定煤尘微观理化特性对其润湿性的影响规律；最后，从气－固－液三相表、界面化学基本理论出发，对煤尘润湿机理进行研究，提出煤尘润湿性评价指标体系及煤尘润湿动力学模型，为从本质上实现对难润湿煤尘的预控提供理论依据。

本项目是针对我国大部分煤层的煤尘润湿性差、微观润湿机理不清晰、降尘效果不佳等问题而提出的。首先，通过22个代表性煤样的工业分析和元素分析结果得到不同变质程度煤样的煤质参数变化规律；利用接触角定量表征煤样的润湿性，对煤质参数与润湿性进行相关性分析，为摸清不同地区不同煤种的润湿性能提供参考。其次，借助FTIR、XRD、NMR和XPS等先进的检测技术，从含氧官能团、微晶结构、碳骨架结构、表面元素四个方面揭示煤的微观结构，得到了不同变质程度煤的表面官能团种类及数量、无机相种类、碳结构等定量信息，从微观层面具体阐释了不同煤种煤尘结构对煤尘润湿性的影响程度和机理，为建立煤的润湿性评价模型提供了研究基础。此外，利用SPSS软件得到理化结构参数与接触角间的相关性系数和偏相关性系数，确定了脱总氧度、氧含量、脱脂肪族C=O度等6个煤尘润湿性主要影响参数。最后，通过多元线性逐步回归，创造性地建立了煤尘润湿性评价模型，并通过了可信度检验，实现了利用煤的微观特征对煤润湿性的快捷有效判别。