摘要
粉煤灰中含有大量的Si、Al元素,可作为合成分子筛的主要原料。通过对粉煤灰合成分子筛的主要工艺进行比较分析,研究了各工艺的优缺点以及合成过程中的主要影响因素。粉煤灰合成分子筛的工艺已由一步水热法开发出:二步水热法、碱熔融法、有机/无机模板剂法、微波/超声波辅助加热法和无溶剂体系法。其中二步水热法、有机/无机模板剂法可通过在原料中添加了硅铝源或模板剂来控制反应方向,提高目标沸石的结晶度;碱熔融法可有效提高粉煤灰中有效物质的活性;微波/超声波辅助加热法可降低合成过程的能耗;无溶剂体系法可有效降低合成过程的水耗。每种合成工艺中可通过控制硅铝比、液固比、碱的种类和浓度、晶化温度等因素来降低合成成本。
Coal fly ash(CFA),containing a large number of Si and Al elements,can be used as the main raw material for the zeolite synthesis.By comparing and analyzing the main technology of zeolite synthesis from CFA,the advantage and disadvantage of each technology were summarized and the major factors in the synthesis process were studied.The technology of zeolite synthesis from fly ash has developed from one-step hydrothermal method to:two-step hydrothermal method,pre-fusion hydrothermal method,organic/inorganic template-mediated method,microwave/ultrasonic assisted heating method and solvent-free system method.Among them,two-step hydrothermal method and organic/inorganic templatemediated method can control the reaction direction by adding silicon and aluminium source or template in raw materials to improve the crystallinity of target zeolite;pre-fusion hydrothermal method can effectively improve the activity of effective materials in fly ash;microwave/ultrasonic assisted method can reduce the energy consumption in the synthesis process;solvent-free system can effectively reduce the water consumption of the synthetic process.The cost can be reduced by controlling the ratio of silicon to aluminum,the ratio of liquid to solid,the type and concentration of alkali,and the crystallization temperature in the synthesis process.
作者
杨丽韫
孟凡绪
袁鹏
钱晓明
李书武
白皓
李宏
YANG Li-yun;MENG Fan-xu;YUAN Peng;QIAN Xiao-ming;LI Shu-wu;BAI Hao;LI Hong(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China)
出处
《硅酸盐通报》
CAS
北大核心
2019年第3期664-672,共9页
Bulletin of the Chinese Ceramic Society
基金
国家科技支撑计划资助项目(2012BAC27B02)
关键词
粉煤灰
分子筛
合成工艺
影响因素
coal fly ash
zeolite
synthetic technology
influence factor
作者简介
杨丽韫(1974-),女,博士,副教授.主要从事工业固体废弃物利用研究;通讯作者:孟凡绪,硕士研究生.
