Molecular mechanism of fly ash affecting the performance of cemented backfill material

Yang, Shuo; Wu, Jiangyu; Jing, Hongwen; Zhuang, Xinguo; Chen, Weiqiang; Wang, Yiming; Yin, Qian; Ma, Dawei

doi:10.1007/s12613-023-2658-x

Cited by 4 publications

(1 citation statement)

References 38 publications

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“…In recent years, researchers have combined the reuse of solid waste with backfilling and mining to develop new filling materials such as tailings [8], fly ash [9][10][11][12][13], coal gangue [14][15][16][17][18] and coal gasification slag [6,[19][20][21]. The reuse of solid waste can alleviate the cost pressure of backfill mining to a large extent, but most solid waste materials (tailings, coal gangue and coal gasification slag, etc.)…”

Section: Introductionmentioning

confidence: 99%

A Preliminary Study on the Improvement of Gangue/Tailing Cemented Fill by Bentonite: Flow Properties, Mechanical Properties and Permeability

Wang,

Chen,

Guo

et al. 2023

Materials

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Backfill mining has significant advantages in safe mining, solid waste utilization and ecological environmental protection, but solid waste materials (tailings, gangue and coal gasification slag, etc.), as derivative residues of the chemical and metallurgical industries, contain a large number of heavy metal elements, which is posing great challenges to the underground environment after backfill. In order to study the feasibility of bentonite for reducing the permeability of gangue/tailing sand cemented backfill body, relevant tests were carried out from the basic performance index, flow performance and mechanical properties of paste backfill materials. The test results show that bentonite has a significant effect on the water secretion rate of cemented fillers, and also promotes the improvement of slump and diffusion diameter of backfill slurry. The enhancement effect of mechanical properties in the early stage is not obvious, mainly concentrated in the middle and late stages of specimen curing. With the increase of bentonite content, the 28-day uniaxial compressive strength increased from 7.1 MPa and 7.9 MPa to 8.7 MPa and 9.0 MPa, respectively. Bentonite is filled between the pores of the cemented backfill with its fine particles and water swelling, which can reduce the porosity and permeability of the gangue and tailings cemented backfill. Therefore, on the premise of satisfying the flow and mechanical properties of paste backfill, bentonite can be used to improve the permeability of cemented backfill and reduce the leaching and migration of heavy metal ions.

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