离子固化剂固化煤矸石粉作用机理

Mechanism of action of coal gangue powder stabilized by ionic stabilizer

现存有大量煤矸石危害环境,为高效规模化利用煤矸石,课题组研发了煤矸石专用离子型固化剂(ICG)。以阜新新邱矿区高值精选后的煤矸石粉为研究对象,采用不同掺量的离子固化剂(0,2,4 L/m^(3))进行固化处理,开展热重试验(TG),通过TG-DTG-DTA联合法对吸附水类型和脱附区间以及质量占比情况进行了分析,采用X射线衍射(XRD)与压汞试验(MIP),分析了不同孔径的孔隙结构特征,以及基于压汞试验数据,对孔隙分形特征进行分析,通过扫描电子显微镜和X射线能谱点扫联合测定法(SEM-EDS),观测固化后煤矸石粉表面形貌特征及表面元素的演变,运用氯化钡缓冲溶液法和电感耦合等离子体发射光谱联合试验(ICP-OES)对阳离子交换量(CEC)及交换种类进行探究。此外,通过吸附水特性和孔隙特征以及阳离子交换量对ICG固化煤矸石粉作用机理进行探究。试验结果表明:固化后煤矸石矿物胶体表面和层间的一部分弱阳离子被ICG水溶液中电离出的的强阳离子和强阳离子基团交换,表面空缺的负电荷被ICG中强阳离子吸附中和,表面负电荷的静电引力减弱,另一部分弱阳离子被ICG中烷基磺酸根的磺基以离子键形式结合,导致阳离子交换量减少,疏水端烷基朝外,减少阳离子的水合作用,减弱材料的亲水性能,进而减少表面结合水的含量,在相同外力作用下固化后煤矸石粉的孔径和孔隙体积更小、孔隙率降低、孔隙结构更加简单,密实度更大。

There are a large number of coal gangue hazardous to the environment,for efficient scale utilization of coal gangue,the group developed a special ionic stabilizer(ICG)for coal gangue.Taking the coal gangue powder after high value selection in Fuxin Xinqiu mining area as the research object,the ionic stabilizer with different doping amount(0,2,4 L/m^(3))was used for reinforcement treatment,thermogravimetric test(TG)was carried out,and the adsorbed water type and desorption interval as well as the mass proportion situation were analyzed by the combined TG-DTG-DTA method,and X-ray diffraction(XRD)and mercury-pressure test(MIP)were used to analyze the The pore structure characteristics of different pore sizes,as well as the pore fractal characteristics were analyzed based on the data from the mercury-pressure test,and the surface morphological characteristics and the evolution of surface elements of the stabilized gangue powder were observed by the combined scanning electron microscopy and X-ray energy spectroscopy point sweeping(SEM-EDS),and the combined barium chloride buffer solution method and inductively coupled plasma emission spectroscopy(ICP-OES)were used to analyze the the cation exchange capacity(CEC)and exchange species were investigated.In addition,the mechanism of ICG stabilization of coal gangue powder was investigated by adsorption water characteristics and pore characteristics as well as cation exchange amount.The experimental results show that:after stabilization,part of the weak cations on the surface and between layers of gangue mineral colloids are exchanged by strong cations and strong cationic groups ionized in the aqueous solution of ICG,the negative charges vacated on the surface are neutralized by adsorption of strong cations in ICG,the electrostatic gravitational force of surface negative charges is weakened,and another part of weak cations are bound by the sulfonyl groups of alkyl sulfonate in ICG in the form of ionic bonds,resulting in the cation exchange amount Reduced hydrophobic end alkyl group facing outward,reduce the hydration of cations,weaken the hydrophilic energy of the material,and then reduce the content of surface bound water,the pore size and pore volume of gangue powder after stabilization under the same external force is smaller,the porosity is reduced,the pore structure is simpler,and the compactness is greater.