基于表面功函数差异的低阶烟煤活性显微组分摩擦电选分离技术的基础研究

The low rank weakly-caking — non-caking coal from northwest region such as Shendong coal field contains more inert macerals, so its caking property, property of liquefaction, gasification and slurry is poor, it is difficult to blend with coking coal in large proportion in the process of coking and producing high concentration coal-water slurry, and affect the total conversion yield and oil yield and gas yield. This project adopts the method of triboelectrostatic separation to separate and enrich active macerals based on the diference of surface work function of active macerals and inert macerals. The enriched active macerals will be blended in precise proportion with other coal according to the process of application to keep a high and stable proportion of active macerals in feed coal. It will increase the blending proportion in the process of coking and the total conversion yield and oil yield or gas yield. The instruments of IR, EPR and XRD et al. will be used to investigate the structure and property of functional group of active macerals and inert macerals, and the surface work function measurement system et al. will be used to survey the surface work function, polarity and quantity of triboelectricity. The charge transfer mechanism will be revealled based on the internal relevance of structure and property of functional group and surface work function and dielectric constant. With optimizing the type of friction material and the structure of triboelectric charger, active macerals will be efficient separated and enriched. It will form the theory and technology of triboelectrostatic separation active macerals.

西北地区如神东煤田的低变质不粘-弱粘煤,惰质组分含量高且波动大，导致其粘结、液化、气化及成浆性能都较差，难以较大比例用于炼焦配煤,影响液化转化率及油收率和气化的产气率，难于制备高浓度水煤浆。本项目应用基于表面功函数差异的摩擦电选方法将活性显微组分分离富集，应用中按工艺要求将富集的活性显微组分按比例精确调配，使原料煤活性显微组分比例高而稳定，提高其在炼焦过程中的配比、提高直接液化的转化率和油收率或气化产率。应用红外、顺磁共振、X-衍射等仪器研究活性显微组分和惰性显微组分的表面结构及官能团特征，应用先进的表面功函数等测试手段研究表面功函数、摩擦带电极性和带电量，通过研究表面结构及官能团特征与表面功函数和介电常数的内在关联机制，揭示活性显微组分和惰性显微组分摩擦带电过程中的电荷转移机理；通过优化摩擦带电器材料及结构，实现活性显微组分的摩擦电选高效分离，形成活性显微组分摩擦电选分离理论与技术。

通过建立表面功函数测量系统、介电常数测量系统、摩擦带电量测量系统和活性显微组分的摩擦电选分离试验机系统,对活性显微组分和惰性显微组分的介电常数、表面功函数、摩擦带电极性和摩擦带电量进行了研究结合红外、激光拉曼光谱、顺磁共振和XRD等现代分析手段研究了活性显微组分和惰性显微组分的表面结构及官能团，揭示了揭示了活性显微组分和惰性显微组分的摩擦带电机理及强化摩擦带电的理论：惰质组中羟基、羰基和羧基的含量远大于镜质组，而它们是能吸引电子的基团，因此惰质组比镜质组更容易得到电子，镜质组中恰恰烃基的含量高，而烃基是排斥电子的基团，因此镜质组比惰质组更容易失去电子，因此当两者碰撞接触时，电子将从镜质组转移至惰质组，镜质组带正电，惰质组带负电，所以在开尔文探针测试结果中惰质组的表面逸出功大于镜质组； 而惰质组含氧基团和亲水基团浓度高，使其更容易吸水，而惰质组的芳碳率高，意味着其电阻率的降低，这两种因素都促使惰质组的导电性及极化能力比镜质组好，这首先表现在其介电常数在相同条件下大于镜质组，而导电性好导致摩擦带电过程中，更容易产生“回流”现象，因此，惰质组的摩擦带电量荷质比小。.形成了煤岩活性显微组分分离的摩擦电选新技术。精煤中活性显微组分的含量由原煤中活性显微组分含量53.6%提高到74.6%。.活性显微组分与惰质组分单组分有效分离的研究将把煤炭的高效洁净利用推向分子级水平，它对应用煤岩组分研究煤的组成、结构和物理化学性质及在配煤炼焦、直接液化等工艺中的转化规律都具有重要的科学意义，特别是在解决高惰质组分低阶烟煤合理、高效、高附加值利用的关键技术中具有广阔的应用前景。