摘要
粉煤灰作为燃煤电厂排放的主要工业固体废弃物,对其进行资源化利用是必然的趋势,粉煤灰合成沸石是其高值化应用的有效途径之一。阐述了粉煤灰碱性水热法合成沸石的机理,体系中硅铝酸盐凝胶的形成是决定因素,且硅铝酸盐晶体形成经历了诱导期、成核期、晶体生长期3个时期。综述了传统一步水热法、二步水热法、微波辅助加热法、碱熔融-水热法、晶种诱导合成法、逐步升温法和渗析-水热法等方法的研究进展,对原料组成、外加碱激发剂、反应时间和温度、液固比、特殊添加剂、反应器种类等影响因素作了分析总结,并对粉煤灰水热合成沸石面临的问题、挑战及发展前景进行了展望。
The given paper is devoted to making a review over the research advances on the successful ways to deal with the coal fly ash（CFA） as one of the main industrial solid wastes from the power-generating plants.In the paper,we have made a brief introduction to the reaction mechanism and the crystal formation steps through the hydrothermal synthesis of the zeolite from CFA,which depends on the formation of the aluminosilicate gel from the reaction system,for the aluminosilicate crystal can be formed during the following three periods：the induced period,the nucleation period and the crystal growth period step by step.In so doing,the zeolite can be made crystallized through a self-catalytic process,with the crystals growing during the said process.Furthermore,we would like to recommend the respective advances in the different hydrothermal processing methods including the conventional hydrothermal synthesis（one-step method）,the two-step method,the microwave-supporting method,the alkaline fusion method,the seedling-inducing method,the gradually heated method and the dialysis hydrothermal method,respectively,with the differences of each method being briefly analyzed.Then,the seedling methods can be chosen according to the types of the target products of zeolite types and the different crystal seeds as the seedling to be induced.It is just by taking all the aforementioned induced methods that it would be possible to reach high-degree idealistic crystallized zeolites of highly possible purity.On the other hand,the simple operation,the mild reaction conditions,the promptly effective reaction time and all the other favorable seedling factors,may all contribute to the advantages of the method.Therefore,as compared with the conventional hydrothermal synthesis the above said methods can help to gain more by-products but less lower purity zeolite,which makes them enjoy brighter prospects for future developments and more worthy popularization.It is just for better popularization priorities of the methods that we have made
出处
《安全与环境学报》
CAS
CSCD
北大核心
2016年第3期273-279,共7页
Journal of Safety and Environment
基金
重庆市前沿与应用基础研究项目(CSTC2014jcyj A20015)
关键词
环境工程学
粉煤灰
水热法
沸石
晶种诱导合成
environmental engineering
coal fly ash
hydrothermal synthesis
zeolite
seeding induced method
