Abstract
The preparation of underground-backfill material from CSW can be used for large-scale disposal of solid waste. The proportion of backfill material plays an important role in transportation and backfilling effect, and the mix-proportion optimization of backfill material is essentially a multi-factor and multi-objective optimization problem. In this paper, to obtain the mix proportion of backfill materials with optimal comprehensive-evaluation indexes, and suitable for the engineering application, the fluidity and strength of backfill material, mainly composed of coal gangue(CG), fly ash (FA), flue gas desulfurization gypsum (FGD gypsum), and gasification coarse slag (GCS), were tested by single-factor transformation method, and the effects of various solid wastes on the slump-flow, bleeding rate and early strength of backfill material were analyzed. The optimal mix proportion of CSW with the slump-flow, bleeding rate, and 3-day and 7-day strengths as the evaluation indicators is FA: GCS: FGD gypsum: CG = 25%:25%:25%:25%, according to the multi-objective decision model. Furthermore, the comprehensive evaluation index that meets the requirements of mine backfilling is obtained by changing the ordinary portland cement (OPC) content, that is, the optimal OPC content is 10% of the total solid waste, and the mass concentration is 78%. Finally, the pore structure, micromorphology, and composition of the backfill material with the optimal mix proportion were studied by Mercury Intrusion Porosimetry (MIP), X-ray Diffraction (XRD), and Scanning Electron Microscope-Energy Dispersive Spectrometer (SEM-EDS). The research results provide a good reference for the field application of CSW for underground backfilling.
Funder
National Program on Key Basic Research Project of China
Research Project of Institute of Energy, Hefei Comprehensive National Science Center
Anhui Province University Graduate Research Project
Subject
General Materials Science
Reference35 articles.
1. Strategic consideration and core technology about environmental ecological restoration in coal mine areas in the Yellow River basin of China;Peng;J. China Coal Soc.,2020
2. Discussion on the utilization of industrial solid waste resources in Ningdong Energy And Chemical Base;Niu;China-Arab States Sci. Technol. Forum,2020
3. Development overview of paste backfill technology in China’s coal mines: A review;Yang;Environ. Sci. Pollut. Res.,2021
4. Prospects of resource utilization and disposal of coal-based solid wastes in Xinjiang;Huang;Coal Sci. Technol.,2021
5. Theory and technology of green filling mining of solid waste underground in coal power base of yellow river basin;Yang;J. China Coal Soc.,2021
Cited by
6 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献