【作者】 李宏伟；

【导师】 郭彦霞； 燕可洲；

【作者基本信息】 山西大学 ， 环境工程， 2023， 硕士

【摘要】 煤矸石作为一种富含碳、硅、铝的混合物,可用于制备多元组分分级孔材料。不仅避免了煤矸石资源化利用过程中组分分离工艺繁杂、产品纯度低的问题,而且制得的分级孔材料具有复合功能特性,因此得到了广泛关注。本文提出以煤矸石为主要原料,通过碱熔-酸浸法和碱熔-水热法分别制备活性炭-介孔硅、活性炭-沸石两种复合分级孔材料的方法。重点研究了煤矸石制备复合分级孔材料的工艺条件和制备机理,并考察了制得材料分别对有机污染物和重金属离子的吸附性能。主要研究结果如下:（1）煤矸石碱熔过程转变机理煤矸石在碱熔过程中,所含的芳香环网状结构碳逐步形成了碎片碳微晶结构。同时,煤矸石中高岭石、石英等结构稳定的铝硅酸盐转化为钾霞石和硅酸钾等易溶于酸的钾铝硅酸盐。对于铝硅酸盐而言,其硅组分是由Q³（1Al）层状结构转变为Q⁴（4Al）架状结构,铝组分是由六配位的[Al O₆]八面体结构转变为四配位的[Al O₄]四面体结构。（2）焙烧样酸浸过程转变机理焙烧样在酸浸过程中,所含的碎片碳微晶结构进一步增加了酸性基团。同时,焙烧样中的钾、铝等元素溶出,硅以非晶态形式富集于渣,其中焙烧样的硅组分由Q⁴（4Al）架状结构转变为Q₄（0Al）、Q₃（0Al）非晶态结构。煤矸石碱熔-酸浸制得的复合材料主要由Si、C元素组成,其颗粒表面分布有层状结构堆积形成的微孔和介孔（微、介孔各占近1/2,比表面积达835.1m²/g,平均孔径为2.97 nm,总孔容为0.62 cm³/g）。（3）焙烧样水热过程转变机理焙烧样在水热过程中,碳结构由规则石墨碳结构向缺陷碳结构转变,铝硅组分由钾霞石转变为K-Chabazite沸石相结构。在此过程中,复合材料的硅结构为重构化Q⁴（4Al）架状结构,铝结构为重构化四配位的[Al O₄]四面体结构。煤矸石碱熔-水热制得的复合材料主要由Si、Al、C元素组成,其微观形貌为“药丸状”,具有微孔和介孔（比表面积可达158.4 m²/g,平均孔径为3.36 nm,总孔容为0.13 cm³/g,其中微孔和介孔各为0.07 cm³/g和0.06 cm³/g）。（4）活性炭-介孔硅和活性炭-沸石分级孔材料的吸附性能活性炭-介孔硅材料可用于水中有机物污染物去除,对MB、MO、Rh B的最大吸附容量分别达148.94mg/g,122.45 mg/g和156.66 mg/g;活性炭-沸石材料可用于水中重金属离子去除,对Cu²⁺、Cd²⁺、Pb²⁺的最大吸附容量分别能够达到128.1 mg/L、220.2 mg/L和437.3mg/L。这两种复合分级孔材料的吸附过程均以单分子层化学吸附为主。更多还原

【Abstract】 As a mixture rich in carbon,silicon and aluminium,coal gangue can be used to prepare multi-component hierarchical materials.Not only does it avoid the problems of complicated component separation process and low product purity,but also the multi-stage pore material produced has multi-functional characteristics.In this paper,two composite materials（activated carbon-mesoporous silica and activated carbon-zeolite）were prepared by alkali fusion-acid leaching and alkali fusion-hydrothermal methods,respectively,using coal gangue as the main raw material.The phase transformation and the development of pore structure in the preparation of hierarchical materials from coal gangue were investigated.The adsorption properties of the produced materials were also investigated for organic matter and heavy metal ions respectively.The main results are as follows:（1）Coal gangue in the alkali fusion process,the aromatic ring mesh structure of carbon contained in the gradual formation of fragmented carbon microcrystalline structure.At the same time,structurally stable aluminosilicates such as kaolinite and quartz in the gangue are transformed into acid-soluble potassium aluminosilicates such as potassium chalcocite and potassium silicate.For aluminosilicates,the silicon component is transformed from a Q3（1Al）lamellar structure to a Q4（4Al）shelf structure.Its aluminium component is transformed from a six-coordinated[Al O₆]octahedral structure to a four-coordinated[Al O₄]tetrahedral structure.（2）Phase transformation of roasted samples during acid leaching.The acidic groups were further increased by the fragmented carbon microcrystalline structure contained in the roasted samples during the acid leaching process.At the same time,the elements such as potassium and aluminium in the roasted sample leach out and silicon is enriched in the slag in an amorphous form.The silicon fraction of the roasted sample changes from a Q4（4Al）shelf structure to a Q4（0Al）and Q3（0Al）amorphous structure.The composite made from the alkali fusion-acid leaching of coal gangue is mainly composed of Si and C elements.The surface of its particles is distributed with micropores and mesopores formed by the accumulation of lamellar structures（the micropores and mesopores account for 1/2,specific surface area is about 835.1 m²/g,average pore diameter is about 2.97 nm and total pore volume is about 0.62 cm³/g）（3）Phase transformation of a roasted sample during hydrothermal process.The roasted samples show a shift from a regular graphitic carbon structure to a defective carbon structure during the hydrothermal process.The aluminium-silica component is transformed from potassium chabazite to a K-chabazite zeolite phase structure.During this process,the silicon structure of the composite is a reconfigured Q4（4Al）shelf structure and the aluminium structure is a reconfigured tetra-coordinated[Al O₄]tetrahedral structure.The composite material produced by alkali fusion of coal gangue-hydrothermal is mainly composed of Si,Al and C elements.The microscopic morphology is"pill-like",with microporous and mesoporous（the specific surface area is about 158.4 m²/g,average pore size is about 3.36nm,total pore volume is about 0.13 cm³/g,micropores and mesopores of 0.07 and 0.06cm³/g respectively）.（4）Adsorption performance of activated carbon-mesoporous silica and activated carbon-zeolite graded pore materials.Activated carbon-mesoporous silica materials can be used for the removal of organic pollutants in water,with maximum adsorption capacities of148.94 mg/g for MB,122.45 mg/g for MO and 156.66 mg/g for Rh B.Activated carbon-zeolite materials can be used for the removal of heavy metal ions in water,with maximum adsorption capacities of 128.1 mg/L for Cu²⁺,220.2 mg/L for Cd²⁺and 437.3 mg/L for Pb²⁺.The adsorption process of both composite graded pore materials was based on single molecular layer chemisorption.更多还原