地质聚合物原位转化沸石分子筛的研究进展  

Research Progresses on In-situ Conversion of Geopolymer into Zeolite

作　　者：张耀君[1] 张叶 韩智超 贺攀阳 陈浩 ZHANG Yaojun;ZHANG Ye;HAN Zhichao;HE Panyang;CHEN Hao(College of Materials Science and Engineering,Xi’an University of Architecture and Technology,Xi’an 710055)

机构地区：[1]西安建筑科技大学材料科学与工程学院,西安710055

出　　处：《材料导报》2020年第23期23033-23041,共9页Materials Reports

基　　金：国家自然科学基金项目(21676209);陕西省重点研发计划项目(2019GY-137);西安建筑科技大学优秀博士论文培育基金(6040318008)。

摘　　要：沸石分子筛是一种具有特定的-Si(Al)-O-Si-骨架结构的无机晶体材料,因其独特的空间网络结构而被广泛应用于吸附、分离、离子交换及催化等领域。然而,沸石分子筛的传统合成方法大多采用水热法,以化学试剂作为硅源及铝源,通过添加模板剂及助模板剂,在一定温度和酸碱条件下进行水热反应。该方法的优点在于制得的粉体具有晶粒发育完整、粒度小等优点,但存在原料昂贵以及粉体沸石分子筛二次成型等诸多弊端。地质聚合物是以天然矿物或铝硅酸盐固体废弃物为前驱体与碱性激发剂反应生成的一类绿色胶凝材料。将地质聚合物原位转化为块体沸石分子筛,不仅具有以生态友好的天然矿物及固体废弃物为原料、无需加入模板剂、成本低廉、反应条件缓和等优点,而且制得的块体沸石分子筛避免了传统粉体沸石分子筛在使用过程中的二次成型,开拓了块体沸石分子筛的制备新工艺及新方法。在环境温度和压力下,将无定形的地质聚合物转化为沸石分子筛晶体在热力学上是难以实现的。但在一定的热养护或水热条件下,地质聚合物可原位转化为沸石分子筛。其原料组成、Si/Al物质的量比、Na 2O/SiO 2物质的量比、H 2O/Na 2O物质的量比、激发剂浓度、水热温度、水热时间等是影响沸石分子筛类型以及沸石分子筛微观结构的主要因素。地质聚合物原位转化沸石分子筛的机理可归结为金属阳离子结构导向机理、有机模板结构导向机理以及晶种结构导向机理。地质聚合物原位转化的沸石分子筛在海水淡化、醇水分离、吸附重金属离子以及气体吸附等领域展现出潜在的应用潜力。将无定形的地质聚合物转化为块体沸石分子筛是地质聚合物发展的新趋势,延伸了地质聚合物的产业链及使用价值。本文提出了目前地质聚合物原位转化沸石分子筛存在的问题以及�Zeolite is a type of inorganic crystal material with a specific-Si(Al)-O-Si-skeleton structure.It is widely used in the fields of adsorption,separation,ion exchange and catalysis due to its unique network structure.Generally,the zeolites are synthesized by hydrothermal method,in which the chemical reagents are used as aluminum source and silicon source,and the template and co-template are added to perform the hydrothermal reaction under a certain temperature and acid or base conditions.Although there are some advantages in traditional hydrothermal method such as the prepared powder with well-defined crystals,and small-sized particles,there are some disadvantages such as expensive raw materials and secondary pollution caused in the forming process.Geopolymer is a novel kind of green cementitious material which is formed by the reaction of natural mineral or aluminosilicate solid wastes with alkaline activator.The conversion of geopolymer into bulk zeolite in-situ not only eco-friendly utilization of natural mineral and aluminosilicate solid waste as raw materials,without the addition of template agents,low cost,and mild reaction conditions,but also the prepared bulk zeolites to simplify the forming process of using powder zeolite,and this is a new technique for synthesis of bulk zeolite.Thermodynamically,it is difficult to convert amorphous geopolymers into zeolite under ambient temperature and pressure,but under the certain curing or hydrothermal conditions,the geopolymer can be converted into zeolite in-situ.Some main factors affect the types and microstructures of zeolites produced,such as raw material composition,the mole ratios of Si/Al,Na 2O/SiO 2 and H 2O/Na 2O,activator concentration,hydrothermal temperature and time.The mechanism about conversion of geopolymer into zeolite in-situ can be divided into the metal cation structural guidance,the organic template structural guidance and the seed structural guidance mechanisms.The bulk zeolites have some potential applications in the field of desalination,alcoho

关 键 词：地质聚合物 原位转化 沸石分子筛 碱性激发剂 水热反应 

分 类 号：TQ172[化学工程—水泥工业]