Utilization of Coal Gangue Aggregate for Railway Roadbed Construction in Practice

Li, Linhao; Long, Guangcheng; Bai, Chaoneng; Ma, Kun; Wang, Meng; Zhang, Sheng

doi:10.3390/su12114583

Cited by 30 publications

(14 citation statements)

References 36 publications

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“…Large-scale and high-intensity mining activities and the utilization of coal resources have produced a large amount of solid waste of coal gangue [1][2][3], occupying a large number of land resources and polluting air, groundwater and soil, resulting in a series of ecological, environmental problems [4][5][6]. The coal gangue and water are mixed into a certain concentration of gangue slurry through the underground slurry preparation system, and the goaf caving zone is filled with adjacent grouting to realize the harmless disposal of coal gangue under the low interference condition of the working face [7,8]. The filtration effect mainly occurs in the flow process of suspension in porous media.…”

Section: Introductionmentioning

confidence: 99%

Grouting mechanism and experimental study of goaf considering filtration effect

Zhu

Ouyang

et al. 2023

PLoS ONE

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The filtration effect significantly affects the gangue slurry velocity and concentration, making it difficult to evaluate the gangue slurry diffusion range. Based on the Darcy seepage law, a seepage theoretical calculation model is established considering the filtration time and space effect. And the "water-cement ratio change matrix" in the seepage process of coal gangue slurry is deduced, revealing the basic mechanism of the porous media filtration effect, and the water-cement ratio gradually increases in the seepage process of gangue slurry. The visual test platform for slurry diffusion in goaf was independently developed for testing. The active heating optical fiber method (AHFO) was used to monitor the flow and diffusion of coal gangue slurry in the collapse zone of goaf, and the gravity gradient and water cement ratio of slurry in goaf were measured. The law of particle sedimentation in the gangue slurry flow process under the filtration effect was revealed, and engineering verification was carried out. The results show that the average slope of the gangue slurry in the gangue accumulation is 6.34%, and the overall flow law of the gangue slurry in the goaf is the first longitudinal expansion and then transverse diffusion. The water-cement ratio near the grouting mouth is smaller than the initial water-cement ratio, the near-end water-cement ratio is smaller, and the far-end water-cement ratio is larger. During on-site filling, the accumulated grouting volume of a single hole is 700 m3, and the gangue slurry diffusion distance is greater than 45m, indicating that the gangue slurry has good fluidity.

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Section: Introductionmentioning

confidence: 99%

Grouting mechanism and experimental study of goaf considering filtration effect

Zhu

Ouyang

et al. 2023

PLoS ONE

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“…According to statistics, by the end of 2019, China's accumulated amount of gangue has exceeded 6 billion tons, forming 1500-1700 gangue hills, covering an area of more than 200 thousand mu, the emission has increased by about 500-800 million t year by year [1]. Countries around the world have conducted a lot of exploration and practice on the comprehensive utilization of coal gangue, forming a comprehensive treatment and utilization system for power generation, road paving, production of building materials, production of chemical raw materials, agricultural application, and underground lling, but the comprehensive utilization rate of coal gangue is less than 30% [2][3][4][5][6][7]. e accumulation of coal gangue has brought great hidden dangers to the environment and personal safety.…”

Section: Introductionmentioning

confidence: 99%

Study on Rheological Characteristics of Uncemented Coal Gangue-Fly Ash Backfill (UCGFB) Slurry Based on Fractal Theory

Jin

Yang

et al. 2022

Advances in Materials Science and Engineering

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In order to explore the influence of gradation and concentration on the rheological parameters of uncemented coal gangue-fly ash backfill (UCGFB) slurry, based on the fractal theory, the particle size distribution of the mixture of coal gangue and fly ash under different mixing ratios are analyzed in this paper. On this basis, the influence of gradation and concentration on rheological parameters of UCGFB slurry are studied and a numerical simulation of slurry transportation is also carried out. The results show that (1) the fractal dimension can well characterize the grading characteristics of UCGFB mixtures, the larger the fractal dimension, the more fine particles in the material. (2) The fractal dimension of 2.628 is a critical point, when the fractal dimension of the mixture is greater than or equal to 2.628, the content of fine particles in the slurry can meet the requirements. On this basis, by adjusting the concentration of the slurry, the slurry can reach a good state. (3) When the slurry concentration reaches 79%, no matter how the gradation of the mixture changes, the rheological parameters of the slurry are at a high level. (4) In this paper, the average pressure loss per unit length pipeline is between 3000–8000 Pa for slurry with different mixing ratios, with a minimum value of 3070 Pa and the maximum value of 7697 Pa. Moreover, the pressure loss of bend is greater than that of straight pipe.

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“…Natural CG is a widespread by-product generated in the process of coal mining or the washing process in the coal industry [ 26 ]. CG is usually a black-gray rock with abundant minerals, organic substances, and stable crystals [ 27 , 28 ]. However, the accumulation of excessive CG in coal related operations can lead to groundwater, air, and land pollution [ 29 , 30 ], and therefore it is crucial to explore new methods for the recycling of CG materials.…”

Section: Introductionmentioning

confidence: 99%

Potential Application of Discarded Natural Coal Gangue for the Removal of Tetracycline Hydrochloride (TC) from an Aqueous Solution

Wan

Wang

Gong

et al. 2022

Toxics

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The generation and accumulation of discarded coal gangue (CG) have severe environmental impacts. CG can adsorb other pollutants in the aquatic environment. However, previous studies have not assessed whether CG can adsorb the emerging contaminant tetracycline hydrochloride (TC). Here, discarded CG taken from a mine was pretreated by crushing, cleaning, and sieving and subsequently applied to the adsorption of TC. The adsorption studies were carried out by batch equilibrium adsorption experiments. Our findings indicated that the adsorption behavior could be accurately described using the quasi-first order kinetic and Langmuir adsorption isotherm models, indicating that monolayer adsorption was the main mechanism mediating the interaction between CG and TC. The adsorption process was classified as a thermodynamic endothermic and spontaneous reaction, which was controlled by chemical and physical adsorption, including electrostatic interaction and cation exchange. The pH of the solution had a great influence on the TC adsorption capacity of GC, with higher adsorption occurring in acidic environments compared to alkaline environments. This was attributed to the changes in CG Zeta potential and TC pKa at different pH conditions. Collectively, our findings demonstrated the potential applicability of discarded CG for the adsorption of TC and provided insights into the adsorption mechanisms.

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Utilization of Coal Gangue Aggregate for Railway Roadbed Construction in Practice

Cited by 30 publications

References 36 publications

Grouting mechanism and experimental study of goaf considering filtration effect

Grouting mechanism and experimental study of goaf considering filtration effect

Study on Rheological Characteristics of Uncemented Coal Gangue-Fly Ash Backfill (UCGFB) Slurry Based on Fractal Theory

Potential Application of Discarded Natural Coal Gangue for the Removal of Tetracycline Hydrochloride (TC) from an Aqueous Solution

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