Mechanical Properties of Clay Based Cemented Paste Backfill for Coal Recovery from Deep Mines

Qiangqiang Cheng, Yaben Guo, Chaowei Dong, Jianfei Xu, Wanan Lai and Bin Du
Additional contact information
Qiangqiang Cheng: School of Architectural Construction, Jiangsu Vocational Institute of Architectural Technology, Xuzhou 221116, China
Yaben Guo: School of Mines, China University of Mining and Technology, Xuzhou 221116, China
Chaowei Dong: School of Mines, China University of Mining and Technology, Xuzhou 221116, China
Jianfei Xu: School of Mines, China University of Mining and Technology, Xuzhou 221116, China
Wanan Lai: School of Mines, China University of Mining and Technology, Xuzhou 221116, China
Bin Du: School of Architectural Construction, Jiangsu Vocational Institute of Architectural Technology, Xuzhou 221116, China

Energies, 2021, vol. 14, issue 18, 1-14

Abstract: Fly ash cement is used to solidify marine clay to prepare marine-clay-based cemented paste backfill (MCCPB) to fill the underground goaf of mines, which not only utilizes solid waste such as fly ash and marine clay, but also controls surface subsidence and protects the environment. To simulate the complex underground mine water environment of the filling body, a dry-wet cycle aquatic environment test under different material ratios and curing ages was designed. The water absorption and unconfined compression strength (UCS) of MCCPB with curing ages of 7 and 28 days under the action of 0, 1, 3, and 7 dry-wet cycles were investigated. The results indicate as the number of dry-wet cycles increases, the surface of MCCPB becomes significantly rougher, and the water content and the solid mass decrease accordingly. Different ratios and curing ages of MCCPB in dry-wet cycles of the UCS tend first to increase, then decrease. Meanwhile, the stress-strain curve of the specimen shows that the trend in the elastic modulus is consistent with that of UCS (first increasing, then decreasing), and that, the minimum UCS value of the specimen still meets the early strength requirements of cemented paste backfill in coal mine geothermal utilization. On the one hand, it proves the feasibility of fly ash cement-solidified marine clay for use as cemented paste backfill in coal mines; on the other hand, it also expands the available range of cemented paste backfill materials in coal mines.

Keywords: mining and backfilling; fly ash cement-treated marine clays; dry-wet cycling; UCS; elastic modulus (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2021
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.mdpi.com/1996-1073/14/18/5764/pdf (application/pdf)
https://www.mdpi.com/1996-1073/14/18/5764/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:14:y:2021:i:18:p:5764-:d:634498

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().