Chutong Zhao, Xiaona Wang, Yi Rao, Chunjiang Yu, Zhongli Luo, Jia Li, Amirhomayoun Saffarzadeh, Chuanfu Wu, Wen Ni, Qunhui Wang
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引用次数: 0
Abstract
To completely replace Portland cement for mine backfilling, MSWI fly ash (FA) and solid metallurgical wastes (ground granulated blast furnace slag, steel slag and flue gas desulphurisation gypsum) were used to prepare fly ash-slag-based binder (FBB). The effect of FA content on the hydration and Pb stabilization mechanisms of the FBB was investigated. When a small amount (15%) of FA was added to FBB, hydration product formation and compressive strength were inhibited during early curing (7 d). However, the additional Ca2+, SO42− and OH− carried by FA could partially promote the formation of ettringite, so that the compressive strength of 28 d was comparable to that of the treatment without FA addition (32.5 MPa). When a high amount of FA (30%) was added, the hydration process was strongly inhibited throughout the entire curing period, and the leaching concentration of Zn (1052 μg/L) exceeded the limits of the GB/T 30760–2014 standard (1000 μg/L). Pb2+ was also found to replace Ca2+ in ettringite to form insoluble Pb-ettringite and Pb2(SO4)O precipitates, resulting in remarkable Pb stabilisation in system. Therefore, if the amount of FA incorporated is appropriate, the use of FA as an additional cementitious material for mine backfilling is an ideal method for recycling FA.
期刊介绍：
International Journal of Environmental Research is a multidisciplinary journal concerned with all aspects of environment. In pursuit of these, environmentalist disciplines are invited to contribute their knowledge and experience. International Journal of Environmental Research publishes original research papers, research notes and reviews across the broad field of environment. These include but are not limited to environmental science, environmental engineering, environmental management and planning and environmental design, urban and regional landscape design and natural disaster management. Thus high quality research papers or reviews dealing with any aspect of environment are welcomed. Papers may be theoretical, interpretative or experimental.
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