硅铝协同利用制备高钙粉煤灰基ZSM-5分子筛  

Preparation of High-Calcium Coal-Fly-Ash-based ZSM-5 Zeolite by Synergistic Utilization of Silica and Aluminum

作　　者：吴邦昊 王永利 展俊岭 张旭鹏 王莹 张钰 WU Bang-hao;WANG Yong-li;ZHAN Jun-ling;ZHANG Xu-peng;WANG Ying;ZHANG Yu(Petrochemical College,Jilin Institute of Chemical Technology,Jilin 132022,Jilin,China;Jilin Jinyu Jidong EP Technology Co.,Ltd.,Jilin 132100,Jilin,China;Chemistry College,Jilin University,Changchun 130012,China)

机构地区：[1]吉林化工学院石油化工学院,吉林吉林132022 [2]吉林金隅冀东环保科技有限公司,吉林吉林132100 [3]吉林大学化学学院,长春130012

出　　处：《有色金属（冶炼部分）》2023年第7期84-91,共8页Nonferrous Metals（Extractive Metallurgy)

基　　金：吉林省科技发展计划项目(20200403170SF)。

摘　　要：利用粉煤灰(CFA)生产分子筛是实现其高附加值利用的有效途径。以高钙粉煤灰为原料,结合高温焙烧、酸浸纯化和碱熔活化等预处理技术,采用变温水热晶化法制备了纯净的ZSM-5分子筛。采用XRD、XRF、FTIR、SEM、NH 3-TPD、OH-FTIR及N 2吸附-脱附等手段对样品的组成、结构、形貌和酸性质进行表征。结果表明,酸浸纯化可去除96%以上的氧化钙,碱熔活化将惰性莫来石晶相转变为可溶性硅铝酸盐。低温-高温两步水热晶化法制备的ZSM-5分子筛结晶度高、粒径小(800 nm×300 nm×100 nm)且分散度好,具有较高的比表面积(319.22 m^(2)/g)、外表面积(48.28 m^(2)/g)和丰富的微孔结构(0.16 cm^(3) g)。与化学试剂为原料一步水热法合成的HZSM-5相比,高钙粉煤灰基HZSM-5酸强度略有下降,总酸量和Bronsted酸量降低,弱酸占比增加,在吸附和催化等领域具有很好的应用潜力。The production of molecular sieves from coal fly ash(CFA)is an effective way to achieve its high value-added utilization.By using high calcium CFA as raw material,pure ZSM-5 molecular sieves were prepared by a variable-temperature hydrothermal crystallization method combining pretreatment techniques such as high temperature roasting,acid leaching purification and alkali fusion activation.The composition,structure,morphology and acid properties of the samples were characterized by XRD,XRF,FTIR,SEM,NH 3-TPD,OH-FTIR and N 2 adsorption-desorption.The results show that acid leaching purification can remove more than 96%of calcium oxide,and alkali fusion activation transforms inert mullite crystalline phase into soluble silica-aluminates.ZSM-5 molecular sieve prepared by two-step hydrothermal crystallization method has high crystallinity,small particle size(800 nm×300 nm×100 nm)and good dispersion,with high specific surface area(319.22 m^(2)/g),high external surface area(48.28 m^(2)/g)and abundant microporous structure(0.16 cm 3 g).Compared with HZSM-5 synthesized by one-step hydrothermal method based on chemical reagents,the high-calcium CFA-based HZSM-5 has slightly lower acid strength,lower total and Bronsted acid amounts,and rises percentage of weak acids,which has good potential for applications in fields such as adsorption and catalysis.

关 键 词：高钙粉煤灰 碱熔活化 变温水热晶化 ZSM-5分子筛 

分 类 号：TQ536.4[化学工程—煤化学工程]