摘要
粉煤灰中含有大量的Si、Al、Fe、Ca等元素,但粉煤灰中的元素被致密的无定型硅铝酸盐玻璃相覆盖,阻碍了其中元素的溶出,对粉煤灰的预活化处理是解决这一问题的关键,联合盐酸酸浸可提取其中的元素。探讨了酸浸条件和水热预处理对粉煤灰中Si、Al、Fe和Ca等元素溶出行为的影响。分别应用电感耦合等离子体发射光谱仪和电子扫描显微镜检测酸浸液中元素的浓度和酸浸渣的形貌变化,结果表明:最佳的酸浸条件为3 mol/L的盐酸、45℃下酸浸1.5 h、液固比为25 mL/g;在374℃下进行预处理,随着碱溶液浓度增加,粉煤灰中更多的元素可被活化而溶于盐酸中;当碱溶液为1.0 mol/L,温度为250℃时,粉煤灰中的Si、Al、Fe和Ca等元素较易溶出,且Al比Si更易被活化、溶于稀盐酸。
Fly ash contains a large amount of Si,Al,Fe,Ca and other elements,but the elements in fly ash are covered by the dense amorphous aluminosilicate glass phase,which hinders the dissolution of the elements in fly ash.Activation treatment is the key to solve this problem.When it is combined with hydrochloric acid leaching,these elements can be extracted.The effects of acid leaching conditions and hydrothermal pretreatment conditions on the dissolution of various elements(Si,Al,Fe,Ca,etc.)in fly ash were studied.The inductively coupled plasma optical emission spectrometry and scanning electron microscopy were used to detect the concentration of elements in the acid leaching solution and the morphological changes of the acid leaching residue.The results show that the optimal conditions of acid leaching were 3 mol/L HCl at 45℃for 1.5 h,with the liquid-solid ratio of 25 mL/g.At 374℃,as the concentration of alkali solution increased,more elements in fly ash were activated and dissolved in hydrochloric acid.When the alkali solution was 1.0 mol/L and the pretreatment temperature was 250℃,these elements(Si,Al,Fe,Ca,etc.)in fly ash were easily dissolved,and Al was more easily activated and dissolved in hydrochloric acid than Si.
作者
马领军
史鹏程
韩丽娜
常丽萍
鲍卫仁
王建成
MA Lingjun;SHI Pengcheng;HAN Lina;CHANG Liping;BAO Weiren;WANG Jiancheng(Key Laboratory of Coal Science and Technology,Ministry of Education and Shanxi Province,Taiyuan University of Technology,Taiyuan 030024,China;College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《太原理工大学学报》
CAS
北大核心
2020年第3期338-344,共7页
Journal of Taiyuan University of Technology
基金
国家自然科学基金资助项目(21978195,21476154)。
关键词
粉煤灰
高温水热
酸碱联合
元素溶出
迁移规律
fly ash
high temperature hydrothermal
acid-base combination
elemental dissolution
migration rule
作者简介
通讯作者:王建成(1978-),男,博士,教授,博士生导师,主要从事煤基固废的高值化利用和气体污染物控制方面的研究,(E-mail)wangjiancheng@tyut.edu.cn。
