Characteristics of High-Carbon-Content Slag and Utilization for Coal-Water Slurry Preparation

Guo, Qinghua; Zhang, Zhiqing; He, Qing; Gong, Yan; Huang, Yongmin; Yu, Guangsuo

doi:10.1021/acs.energyfuels.0c02882

Cited by 20 publications

(2 citation statements)

References 31 publications

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“…Blending the waste with coal powder to prepare a waste–coal–water slurry (WCWS) has become an important way for resource utilization and waste disposal, reducing the use of fossil fuels and natural raw materials and alleviating the shortage of capacity for waste disposal . During the combustion and gasification of WCWS, the inorganic components in waste materials are deposited in fly ash and slag, and the organic fractions are turned into small molecule gases. ,− Due to the high calorific value of combustible waste that can decrease the ignition temperature, the technologies of low-temperature WCWS combustion make the concentrations of pollutant emissions reduced considerably. − …”

Section: Future Perspectives and Challengesmentioning

confidence: 99%

Review and Perspectives of Anionic Dispersants for Coal–Water Slurry

Feng

et al. 2023

Energy Fuels

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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.

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Section: Future Perspectives and Challengesmentioning

confidence: 99%

Review and Perspectives of Anionic Dispersants for Coal–Water Slurry

Feng

et al. 2023

Energy Fuels

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“…Therefore, mineral particles in slag samples contain both inorganic matter and carbon. [26][27][28][29] Figures 5 and 6 present the SEM images and surface elemental compositions of carbon particles in S-b and S-s.…”

Section: Surface Morphologies and Elemental Compositions Of Slag Samplesmentioning

confidence: 99%

Understanding the slag transformation behaviors during entrained‐flow gasification based on comparative analysis of slag properties

Wang

Bao

et al. 2021

Asia-Pacific J Chem Eng

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In this work, four slag samples were collected from the OMB CWS gasification, and the mineral behavior and morphology were studied to explore the formation mechanism of blockage slag. Results showed that amorphous phase is dominant in all slag samples, which was mainly glassy substances rich in low-temperature eutectic of iron. The precipitation of metallic iron and the crystals of SiC, calcite, and quartz were found in slags which were taken from the bottom of the combustion chamber (S-b). The quench slag collected from stable operation conditions (S-s) had a low content of quartz crystalline. While slag from the down pipe of the quench chamber (S-b) and bulk slag from the water-cooled pool (S-p) had observed the precipitation of crystals. Comparing to S-s, carbon matters in S-b had a higher order degree of carbon structure. By comparing the slag sample obtained during stable operation (S-s) with slag blocking occurs (S-b, S-d, S-p), it is found that the blockage of the OMB CWS gasifier was strongly related to unreacted residual carbon and the high content of sodium and iron in coal. They will interact with each other and form small number of crystals and most of the amorphous material.

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