煤尘微细观润湿特性及抑尘剂研发初探——以平顶山矿区为例

煤矿开采逐渐向深部延伸,深部开采条件下煤尘灾害频发,防控难度高,除尘机理与技术仍然是深部开采科学高效除尘基础研究的难点与重点之一。以平顶山矿区丁、戊、己、庚4组煤层采集的原煤为研究对象,联合多种煤尘物理化学性质测试(工业分析,XRD,BET,SEM,FT-IR)、分子动力学模拟等手段,系统采用基础物性特征分析、润湿特性多因素影响探讨、分子层面润湿机理探索、抑尘剂改性讨论的研究思路,开展了基于煤尘微细观结构特征的除尘机理探索及新型抑尘剂研发初探。研究表明:平顶山矿区丁戊己庚4组煤层典型煤尘的润湿性大小顺序为戊>丁>庚>己,煤中有机质质量分数、水分质量分数、灰分质量分数、无机矿物成分质量分数、比表面积、含氧官能团等指标的显著差异将对煤尘润湿性能产生显著影响,比表面积、石英质量分数、羟基和醚键数量越多,润湿性越好,固定碳质量分数越高,润湿性越差。联合煤的红外光谱分析和分子动力学模拟,根据平顶山矿区煤尘亲水官能团特征,研究了水分子在不同数量羟基和醚键修饰的煤表面吸附过程,进一步揭示了煤尘润湿性能的强关联因素,表面羟基数量正相关于吸附水分子能力,而煤尘醚键数量对于吸附水分子能力存在极大值。基于煤尘微细观特征对其润湿性的影响机制,考察了3种非离子表面活性剂对4组煤尘的润湿除尘特性,基于表面活性剂分子结构对煤尘润湿的作用机理,针对平煤矿区煤尘提出了引入芳香环结构实现新型抑尘剂改性的解决思路。

Micro-wetting characteristics of coal dust and preliminary study on the development of dust suppressant in Pingdingshan mining area

Coal mining is gradually extending to the deep,coal dust disasters occur frequently under the condition of deep mining,and the dust prevention and control is difficult.Coal dust removal mechanism and technology is still one of the difficulties and emphases in the basic research of scientific and efficient coal dust removal technology in deep mining.The mechanism of coal dust removal based on the microstructure characteristics of coal dust as well as the development of new coal dust suppressant was explored,utilizing the raw coal collected from the coal seam Ding,Wu,Ji and Geng of Pingdingshan Mining Area.Basic physical properties analysis(industrial analysis,XRD,BET,SEM and FT-IR),multi factor influence on wetting characteristics,wetting mechanism exploration at the molecular level and coal dust wetting agent modification discussion were conducted systemically by means of various physicochemical properties testing and molecular dynamics simulation.The results show that the wettability of the four typical coal samples increases in the order of the coal seam Ji,Geng,Ding and Wu.The significant differences of organic matter content,moisture content,ash content,inorganic mineral content,specific surface area and oxygen-containing functional groups in coal dust show some significant impact on the wettability of coal dust.The results show that the greater the specific surface area,quartz content,hydroxyl and ether bond content are,the better the wettability,and the higher the fixed carbon content,and the worse the wettability.Using the results of infrared spectroscopy and molecular dynamics simulation of coal,and considering the characteristics of hydrophilic functional groups of coal dust in Pingdingshan mining area,the adsorption process of water molecules on coal surface modified by different numbers of hydroxyl and ether bonds was studied,and the strong correlation factors of wettability of coal dust were further revealed.The number of surface hydroxyl is positively related to the ability of adsorbing water molecules,while the number of ether bonds in coal dust has a maximum value for the ability of adsorbing water molecules.Based on the influence mechanism of micro characteristics of coal dust on its wettability,the wetting and dust removal characteristics of three kinds of non-ionic surfactants on four groups of coal dust were investigated.According to the wetting mechanism of surfactant molecular structure on coal dust,the solution of introducing aromatic ring structure to realize the modification of new dust suppressor was proposed for the coal dust in Pingdingshan Mining Area.