Research on the slurrying performance of coal and alkali-modified sludge

Chu, Ruizhi; Li, Yulong; Meng, Xiuxia; Fan, Lulu; Wu, Guoguang; Xiao, Li; Jiang, Xiaofeng; Yu, Shi; Hu, Yuanfeng

doi:10.1016/j.fuel.2021.120548

Cited by 22 publications

(7 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…and organic solid wastes (petrochemical and coal–chemical wastes, municipal solid waste, organic sludge, biomass-like solid waste, etc. ), which would bring serious threats to the ecological environment. − Accordingly, oil, organic solvents, and wastewater (industrial wastewater, petroleum and coal processing wastewater, sewage sludge wastewater, etc.) can be used as substitutes for the aqueous medium to efficiently recycle the heat value and deal with pollutants. − The inorganic matters in CWS can be deposited in slag and fly ash after combustion and gasification, and the organic substances can be converted chemically or burned directly to generate electricity.…”

Section: Introductionmentioning

confidence: 99%

Review and Perspectives of Anionic Dispersants for Coal–Water Slurry

Feng

et al. 2023

Energy Fuels

View full text Add to dashboard Cite

Dispersants are chemical moieties that modify interfacial characteristics by adsorption at the solid–liquid interface, and they have been widely used in modern industrial production. This review focuses on the research and perspectives of anionic dispersants for coal–water slurry (CWS). Various common anionic dispersants are briefly summarized, including natural and synthetic species. The interactions between coal particles in the CWS suspension, including van der Waals attraction and electrostatic repulsion, are described by the DLVO (Derjaguin–Landau–Verwey–Overbeek) theory. Due to the hydrophobic interaction and the steric effect resulting from the adsorption of polymer dispersants, the extended DLVO theory is introduced to elucidate the various interactions in the CWS system. Based on the interactions between the coal particles, the adsorption behaviors at the coal–water interface, and the interactions between coal and water, the dispersion and stabilization mechanisms are systematically and theoretically discussed. According to the variations of interaction energies between the coal particles, the use of anionic polymer dispersants can weaken the hydrophobic attraction and enhance the steric hindrance and electrostatic repulsion. Also, the rheological behaviors of CWSs are outlined, with emphasis on the pipeline transportation of CWS and the three-parameter Herschel–Bulkley model. Additionally, the properties of anionic dispersants for CWS can be improved by adjusting their chemical structures such as molecular weight, side chain length, rigidity and flexibility of the molecular chain, and variety, quantity, position, and proportion of hydrophobic and hydrophilic groups. In view of the relationships between the structure and property, a direction on the selection and preparation of dispersant for CWS is suggested. Finally, the current challenges and future perspectives of dispersants for CWS are put forward.

show abstract

Section: Introductionmentioning

confidence: 99%

Review and Perspectives of Anionic Dispersants for Coal–Water Slurry

Feng

et al. 2023

Energy Fuels

View full text Add to dashboard Cite

show abstract

“…Meanwhile, the filling slurry used in the field of fracture body injection is usually a cement slurry or a chemical slurry [29][30][31]. Generally, its purpose is to increase the groutability and diffusivity of the slurry, but the modification cost is higher [32][33][34][35]. Therefore, significant differences exist between the two engineering contexts.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on the Diffusion Radius of Modified Slurry Used in Longwall Overburden Isolated Grouting

Xuan

Zhang

et al. 2023

Geofluids

View full text Add to dashboard Cite

The slurry diffusion radius is an important parameter in grouting engineering. In some cases, injection into partial overburden is needed in grouting engineering, and it is thus critical to control the slurry diffusion so as to reduce unnecessary grout take. In an effort to solve such issues in longwall overburden grouting, we proposed the addition of cement as a means of modifying fly ash slurry in order to reduce grout diffusion and grout take. The characteristics of the modified slurry were determined under different water-ash ratios and cement-blending ratios. The cement-blending ratio was found to have a small effect on the density of the slurry but a significant effect on the slurry’s precipitation rate and viscosity. The slurry diffusion experimental system was established to study the diffusion radius and consolidation. Results for both the fly ash slurry and the modified slurry revealed a circular diffusion pattern centered around the grouting borehole. The diffusion radius of the modified slurry made with 10% cement was 19.4% lower than that of the fly ash slurry, but its solidification thickness appeared to increase. The modified slurry diffusion had a two-stage effect: a “stability control stage” and a “consolidation control stage.” In the consolidation control stage, the diffusion radius of the modified slurry was smaller than that of the fly ash slurry, and this stage was the key to control the diffusion radius of the slurry. Field trials were conducted based on the results of the study, and grout take was reduced effectively. This research provides a theoretical basis for slurry diffusion radius control in longwall grouting.

show abstract

“…This results in nonuniform adsorption of additives on the coal surfaces, which influences slurry performance. 10 , 11 Electrostatic repulsion is provided by the charges on the coal surfaces, which disperses the coal particles and improves the stability of the slurry. 12 , 13 The nonuniformity of coal surface structures is not beneficial to slurryability; therefore, additives are used in CWS to improve this situation.…”

Section: Introductionmentioning

confidence: 99%

“…The properties of CWS are influenced by the physical and chemical properties of the coal surfaces, such as their oxygen-containing functional groups, electric charges, hydrophilicity, inherent moisture, and pore structure. , Additives are reversely adsorbed on coal surfaces because of the presence of oxygen-containing functional groups. This results in nonuniform adsorption of additives on the coal surfaces, which influences slurry performance. , Electrostatic repulsion is provided by the charges on the coal surfaces, which disperses the coal particles and improves the stability of the slurry. , The nonuniformity of coal surface structures is not beneficial to slurryability; therefore, additives are used in CWS to improve this situation. The hydrophobic structure of the additives is adsorbed onto coal surfaces and links to the water molecules through the hydrophilic end, which makes the wettability of the coal surfaces more uniform.…”

Section: Introductionmentioning

confidence: 99%

Slurryability and Influencing Mechanism of Hydrophobic Structures in Additive–Coal–Water Ternary System

Zhang

Chu

et al. 2022

ACS Omega

Self Cite

View full text Add to dashboard Cite

This study investigates the effects of additive adsorption onto coal particles on surface properties, hydrophobic groups on the slurryability, and the moisture occurrence form on the performance of coal water slurry (CWS). Mechanisms related to the different hydrophobic structures of the additives are proposed. The adsorption method of sulfonated acetone formaldehyde enhances the adsorption capacity of coal surfaces but is not conducive to slurrying. Sodium lignin sulfonate has hydrophobic ends with nonpolar aromatic groups, three-dimensional macromolecular structures, and complex branched chains, which provide CWS with good stability and slurryability. Naphthalenesulfonate formaldehyde has a double benzene ring structure and provides the thick but nonuniform adsorption layers on coal surfaces. The many amorphous structures and low molecular weights of sodium humic sulfonate lead to nonuniform hydration films and poor slurryability. The results of this paper provide guidance for improving synergism in coal–water–additive systems and enhancing slurry performance.

show abstract

Research on the slurrying performance of coal and alkali-modified sludge

Cited by 22 publications

References 26 publications

Review and Perspectives of Anionic Dispersants for Coal–Water Slurry

Review and Perspectives of Anionic Dispersants for Coal–Water Slurry

Experimental Study on the Diffusion Radius of Modified Slurry Used in Longwall Overburden Isolated Grouting

Slurryability and Influencing Mechanism of Hydrophobic Structures in Additive–Coal–Water Ternary System

Contact Info

Product

Resources

About