Introduction
Bimonthly, started in 1957
Administrator
Shanxi Provincial Education Department
Sponsor
Taiyuan University of Technology
Publisher
Ed. Office of Journal of TYUT
Editor-in-Chief
SUN Hongbin
ISSN: 1007-9432
CN: 14-1220/N
Administrator
Shanxi Provincial Education Department
Sponsor
Taiyuan University of Technology
Publisher
Ed. Office of Journal of TYUT
Editor-in-Chief
SUN Hongbin
ISSN: 1007-9432
CN: 14-1220/N
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Study on the anti-seepage performance of compacted tailing sand-bentonite mixture in landfill cover system
DOI:
10.16355／j.tyut.1007-9432.20230621
abstract:
To achieve the reuse of solid waste, this study explores the feasibility of using compacted tailings-bentonite material as an impermeable material for landfill cover system. The maximum dry density of tailings-bentonite mixtures with varying bentonite content was determined through compaction tests. Saturated permeability coefficients of the tailings-bentonite mixtures were measured using a consolidation permeameter. Additionally, the pore characteristics of the samples were analyzed through mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) tests. Finally, the service performance of compacted tailings-bentonite mixture in cover systems was investigated using numerical simulations. The results reveal that the maximum dry density of the tailings-bentonite mixture first increases and then decreases with increasing bentonite content, reaching a maximum of 1.94 g/cm3 at 10% bentonite content. The permeability coefficient of the compacted tailings-bentonite mixture decreases with the increase of bentonite content. A bentonite content of 10% or higher satisfies the permeability requirement for the impermeable layer, i.e., ks = 5.61×10-10 m/s, ≤10−9 m/s; in this case, an impermeable layer with a thickness of 10 cm meets the requirement that annual percolation ≤ 30 mm. Additionally, setting a certain slope to facilitate lateral drainage can effectively reduce the percolation through landfill cover system.
Keywords:
landfill cover system; tailings; bentonite; permeability; percolation