期刊
SCIENCE OF THE TOTAL ENVIRONMENT
卷 784, 期 -, 页码 -出版社
ELSEVIER
DOI: 10.1016/j.scitotenv.2021.147100
关键词
High-alumina coal fly ash; Microstructure characteristics; Mechanochemical activation; Particle size; Recycling; Mullite
资金
- PhD early development program of Nanchang Hangkong University [EA201902306]
This study successfully removed the amorphous phase from HAFA and increased the Al2O3/SiO2 mass ratio through a novel mechanochemical activation-desilication process, resulting in excellent mullite refractory materials.
High-alumina coal fly ash (HAFA) is a special solid waste since its alumina content can reach 40-50 wt%, which is seen as a potential resource for mullite material production. However, obtaining an ideal mullite material from HAFA is difficult because of its low Al2O3/SiO2 mass ratio. In this work, the microstructure characteristics of HAFA were systematically analyzed by combining multiple characterization techniques. It was found that HAFA had a core-shell structure with a mullite/corundum crystal core and a silica-rich amorphous phase shell. The novel mechanochemical activation-desilication process was used to remove amorphous phase from HAFA and elevate the Al2O3/SiO2 mass ratio. In particular, the effect of particle size after mechanical treatment and mechanism of the desilication process were extensively investigated. On decreasing the particle size, a high leaching rate of alumina was achieved during mechanochemical activation, thus generating a hydroxysodalite coating layer as desilication was suppressed, and the amorphous phase was effectively removed. The mineralogical phase of the desilicated HAFA is mainly mullite and corundum, and the Al2O3/SiO2 mass ratio was elevated from 1.29 to 3.02. Mullite refractory obtained from the desilicated HAFA exhibited excellent physical properties. This study provides insights into further high-valued utilization of HAFA. (C) 2021 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据