粉煤灰改性及其资源化应用进展
2021-10-03胡少军李帅吴求刚范玉超
胡少军 李帅 吴求刚 范玉超

摘 要:粉煤灰作为一种传统的固体废物,因产量大、利用率低而大量堆积,污染周边环境。由于粉煤灰具有独特的玻璃体结构、比表面积大、孔隙度发达、结构稳定等特点,在土壤修复以及废水治理等领域具有较好的应用潜力。因此,对粉煤灰进行资源化利用是解决其堆积与污染的有效途径之一。该文综述了当前改善粉煤灰性能的物理、化学和生物改性方法及其机制,讨论了其在建筑业、农业、环境修复领域的应用进展,并对粉煤灰长期应用风险及改性研究方向进行了展望,以期为改性粉煤灰的制备及其应用提供参考。
关键词:粉煤灰;改性;应用;风险;资源化
中图分类号 U414文献标识码 A文章编号 1007-7731(2021)18-0165-05
Progress in Modification of Fly Ash and its Resource Utilization
HU Shaojun1, 2, 3 et al.
(1School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China; 2Jiangsu Institute of Geological and Mineral Design; Xuzhou 221006, China; 3Engineering Laboratory of Anhui Province for Comprehensive Utilization of Water and Soil Resources and Construction of Ecological Protection in Mining Area with High Groundwater Level, Huainan 232001, China)
Abstract: As a traditional solid waste, large amounts of fly ash are accumulated due to its large yield and low utilization rate. The fly ash has great potential in soil and wastewater remediation due to its unique vitreous structure, large specific surface area, developed porosity, and stable structure, etc. Therefore, the recycling of fly ash is an effective way to solve its accumulation and environmental pollution. In this paper, physical, chemical and biological modification methods of fly ash and their mechanisms were discussed in detail. Then, the application progresses of fly ash in the fields of construction, agriculture and environmental remediation were elaborated as well. Finally, we prospected the long-term application risk and the research direction of modification of fly ash in future. This review would provide theoretical guidance for the modification and application of fly ash.
Key words: Fly ash; The modification; Application; Risk; Resource recovery
1 粉煤灰概述
煤基固废是指粉煤灰、煤矸石、脱硫石膏、煤泥、煤化工废渣等煤炭开发利用过程中产生的固体废弃物[1]。其中,粉煤灰是火电厂排放的最主要固体废弃物之一,是燃煤电厂经捕尘装置从烟气中收集而得的细灰,也称为飞灰[2]。近年来,随着资源消耗量的增加,粉煤灰产量呈逐年上升趋势。根据中国生态环境部2020年12月发布的《2020年全国大、中城市固体废物污染环境防治年报》,2019年我国工业企业粉煤灰年产量约5.4?108 t,综合利用率为74.7%,已成为中国最大单一固体污染源[3]。虽然利用率在提高,但粉煤灰总量巨大,露天堆放占用大量土地,使农业耕地面积受到限制,甚至污染周边土壤和水体。
粉煤灰的主要成分为SiO2与Al2O3,独特的凝胶性能及特有的球形结构和粒度分布等特征,使其具有多种潜在的综合利用价值[4]。……
