Preparation of coal gangue-slag-fly ash geopolymer grouting materials

Guo, Lingzhi; Zhou, Mei; Wang, Xinyi; Li, Chao; Jia, Hanqing

doi:10.1016/j.conbuildmat.2022.126997

Cited by 80 publications

(15 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…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].…”

Section: Introductionmentioning

confidence: 99%

Grouting mechanism and experimental study of goaf considering filtration effect

Zhu

Ouyang

et al. 2023

PLoS ONE

View full text Add to dashboard Cite

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.

show abstract

Section: Introductionmentioning

confidence: 99%

Grouting mechanism and experimental study of goaf considering filtration effect

Zhu

Ouyang

et al. 2023

PLoS ONE

View full text Add to dashboard Cite

show abstract

“…The components of coal gangue are mainly organic carbonaceous and inorganic aluminosilicate minerals, which can be used as siliceous or aluminum raw materials. Recently, certain scholars have used alkali activation technology to activate coal gangue [ 13 , 14 , 15 , 16 ]. Coal gangue is used as an aggregate.…”

Section: Introductionmentioning

confidence: 99%

Study on Mechanical Properties and Micro Characterization of Fibre Reinforced Ecological Cementitious Coal Gangue Materials

et al. 2023

View full text Add to dashboard Cite

Eco-gelled coal gangue materials (EGCGMs) are usually produced using coal gangue, slag, and fly ash in a highly alkaline environment. Herein, to improve the mechanical properties of such materials, polypropylene fibers were uniformly mixed with them. An unconfined compressive strength test and a three-point bending test of the fiber-reinforced EGCGMs under different conditions were conducted. Based on the performance degradation control technology of the fiber structure, the interface mechanism of the composite materials was analyzed from the micro level using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). In the mechanical test, the 28 d UCS and flexural properties of the fiber-reinforced EGCGMs were analyzed using the Box–Behnken design response surface design method and orthogonal design method, respectively. The order of significance was as follows: sodium hydroxide, fiber length, and fiber content. Within the scope of the experimental study, when the NaOH content is 3, the fiber content is 5 ‰, and the fiber length is 9 mm, the mechanical properties are the best. Based on the microscopic equipment, it was discovered that the amorphous ecological glue condensation product formed by the reaction of slag and fly ash in the alkaline environment was filled between the coal gangue particles and the fibers, and several polymerization products accumulated to form a honeycomb network topology. The distribution of fibers in the EGCGM matrix could be primarily divided into single embedded and network occurrences. The fiber inhibits the crack initiation and development of the matrix through the crack resistance effect, and improves the brittleness characteristics through the bridging effect during the failure process, which promotes the ductility of the ecological cementitious coal gangue matrix.The results presented herein can provide a theoretical basis for improving the mechanical properties of alkali-activated geopolymers.

show abstract

“…Yan et al analyzed the microstructure of metakaolin-sodium silicate double-liquid grouting material and found that the grouting material has good durability compared with ordinary cement-silicate doubleliquid grouting material [22]. Guo et al used coal gangue, fly ash, and slag to prepare grouting materials with clean production, high strength, and seepage pressure by response surface methodology [23]. Zhao et al used uncalcined coal gangue and municipal solid waste incineration fly ash to prepare cementitious materials and found that the formation of N-A-S-H in the stone body provided strength, and the heavy metal ions in municipal solid waste incineration fly ash were solidified in the final formed geopolymer, reducing its toxicity [24].…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Ratio and Performance of Coal Gangue/Bottom Ash Geopolymer Double-Liquid Grouting Material

Zhao¹,

Sun²,

Cao³

et al. 2023

Journal of Renewable Materials

View full text Add to dashboard Cite

Mine grouting reinforcement and water plugging projects often require large amounts of grouting materials. To reduce the carbon emission of grouting material production, improve the utilization of solid waste from mining enterprises, and meet the needs of mine reinforcement and seepage control, a double-liquid grouting material containing a high admixture of coal gangue powder/bottom ash geopolymer was studied. The setting time, fluidity, bleeding rate, and mechanical properties of grouting materials were studied through laboratory tests, and SEM analyzed the microstructure of the materials. The results show that the total mixture of calcined gangue does not exceed 60%. And the proportion of bottom ash replacing cement should be within 30%. At the same time, the volume mixture of sodium silicate is 20%. And the water-solid ratio does not exceed 0.6. The stability of the slurry prepared under this ratio is good. The microstructure of the stone body is dense, and its strength can meet the requirements of rock reinforcement and seepage control. Its economic and environmental benefits are more significant than the traditional cement-silicate double-liquid grouting material.

show abstract

Preparation of coal gangue-slag-fly ash geopolymer grouting materials

Cited by 80 publications

References 37 publications

Grouting mechanism and experimental study of goaf considering filtration effect

Grouting mechanism and experimental study of goaf considering filtration effect

Study on Mechanical Properties and Micro Characterization of Fibre Reinforced Ecological Cementitious Coal Gangue Materials

Experimental Study on Ratio and Performance of Coal Gangue/Bottom Ash Geopolymer Double-Liquid Grouting Material

Contact Info

Product

Resources

About