NaAlO_(2)硫酸法合成高质量拟薄水铝石  

Synthesis of high-qualified pseudo-boehmite by NaAlO_(2) sulfuric acid method

作　　者：罗铃 李平[2,3] 黄凯[1] 张海林[2,3] 陈兴 刘文科[2] 郑诗礼 Ling LUO;Ping LI;Kai HUANG;Hailin ZHANG;Xing CHEN;Wenke LIU;Shili ZHENG(School of Metallurgy and Ecological Engineering,Beijing University of Science and Technology,Beijing 100083,China;National Engineering Research Center for Green Recycling of Strategic Metal Resources,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China;Institute of Resources and Ecological Environment,Ganjiang Innovation Academy,Chinese Academy of Sciences,Ganzhou,Jiangxi 341119,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]中国科学院过程工程研究所战略金属资源绿色循环利用国家工程研究中心,北京100190 [3]中国科学院赣江创新研究院资源与生态环境研究所,江西赣州341119

出　　处：《过程工程学报》2022年第12期1710-1718,共9页The Chinese Journal of Process Engineering

基　　金：国家自然科学基金资助项目(编号:51974285);中国科学院重点部署项目(编号:ZDRW-CN-2021-3)。

摘　　要：拟薄水铝石常应用于石油化工、环保等行业,是活性氧化铝的前驱体、分子筛、黏结剂等的重要原料。近年来,我国石油化工行业面临严峻挑战,原油劣质化、重质化,产品轻质化、清洁化和成本高等问题愈加突出,迫切需求拟薄水铝石的低成本生产制备方法。本工作采用NaAlO_(2)硫酸法结合动态调控pH合成了物相纯、具有特定孔结构的拟薄水铝石产品。通过XRD,BET,SEM,NMR等表征分析得出,硫酸法在pH=7、75℃下反应0.5 h可合成比表面积、孔容和平均孔径分别为341.01 m^(2)/g,0.41 cm^(3)/g,4.78 nm的γ-AlOOH,在极端合成条件会生成Al(OH)_(3)杂相。动态调控pH可以有效促进产品相纯化和孔结构改善。在70℃、NaAlO_(2)和Al_(2)(SO_(4))_(3)流速15 mL/min、反应10 min、老化10 min的条件下,杂相Al(OH)_(3)向γ-AlOOH转变,可将含有28.2%的Al(OH)3杂相经过摆动后降至3.1%,纯化后的γ-AlOOH结晶度增强,其中27Al以六配体形式存在,比表面积、孔容和平均孔径分别增加到358.88 m^(2)/g,0.70 cm^(3)/g和7.83 nm。Pseudo-boehmite,as a catalyst carrier,molecular sieve,and raw material for the production of activated alumina,is widely used in petrochemical,nitrogen fertilizer,environmental protection,and other industries.In recent years,China’s petrochemical industry has faced severe challenges such as heavy and inferior crude oil,lighter,and high costs.The traditional synthesis of pseudo-boehmite includes the neutralization method and alcohol aluminum hydrolysis method,which the former has low cost and easy industrial practice,but the pore structure is poor.The latter can produce high-purity γ-AlOOH,but it has high cost and technical barriers,and there is an urgent need for low-cost production of pseudo-boehmite.Based on the controlled colloidal precipitation dissolution equilibrium of Al(OH)_(3) micelles,γ-AlOOH could be prepared by adding H_(2)SO_(4) into NaAlO_(2)solution.This manuscript aimed at synthesizing γ-AlOOH with purified phase and specific pore structure by NaAlO_(2)and H_(2)SO_(4) method combined with the pH swing technique.The γ-AlOOH was characterized by XRD,BET,SEM,NMR,etc.,in which the specific surface area,pore volume,and average pore diameter were 341.01 m^(2)/g,0.41 cm^(3)/g,and 4.78 nm,respectively,was synthesized by adding H_(2)SO_(4) into NaAlO_(2) solution at 75℃,pH=7 and 30 min.It was also found that extreme synthesis temperature and terminal pH value lead to the formation of Al(OH)_(3) in γ-AlOOH,and the pH swing technology could effectively promote the transformation of the Al(OH)_(3) to γ-AlOOH,with the Al(OH)_(3) phase decreased from 28.2% to 3.1%.The crystallinity of pure γ-AlOOH increased during the swing process,and ^(27)Al exists in the form of six ligands.Finally,the specific surface area,pore volume,and average pore diameter of γ-AlOOH were increased to 358.88 m^(2)/g,0.70 cm^(3)/g,and 7.83 nm,respectively,with the temperature of reaction at 70℃,the addition rate of NaAlO_(2)and Al_(2)(SO_(4))_(3)of 15 mL/min,reaction and aging time for 10 min.

关 键 词：铝酸钠 硫酸 拟薄水铝石 pH摆动技术 孔结构 

分 类 号：TQ133.1[化学工程—无机化工]