SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2022, Vol. 44 ›› Issue (4): 275-283.DOI: 10.1016/j.cjche.2021.03.001

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Investigation on the effects of fluid intensification based preconditioning process on the decarburization enhancement of fly ash

Danlong Li1,2, Yannan Liang1,2, Hainan Wang1,2, Ruoqian Zhou1,2, Xiaokang Yan1,2, Lijun Wang1,3, Haijun Zhang1,2   

  1. 1 National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, China;
    2 School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China;
    3 School of Electrical and Engineering, China University of Mining and Technology, Xuzhou 221116, China
  • Received:2020-11-19 Revised:2021-02-25 Online:2022-06-18 Published:2022-04-28
  • Contact: Haijun Zhang,E-mail:zhjcumt@cumt.edu.cn
  • Supported by:
    The authors would like to acknowledge financial support from National Natural Science Foundation of China (51722405, 51974310), National Key Research and Development Project of China (2019YFC1904301).

Investigation on the effects of fluid intensification based preconditioning process on the decarburization enhancement of fly ash

Danlong Li1,2, Yannan Liang1,2, Hainan Wang1,2, Ruoqian Zhou1,2, Xiaokang Yan1,2, Lijun Wang1,3, Haijun Zhang1,2   

  1. 1 National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, China;
    2 School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China;
    3 School of Electrical and Engineering, China University of Mining and Technology, Xuzhou 221116, China
  • 通讯作者: Haijun Zhang,E-mail:zhjcumt@cumt.edu.cn
  • 基金资助:
    The authors would like to acknowledge financial support from National Natural Science Foundation of China (51722405, 51974310), National Key Research and Development Project of China (2019YFC1904301).

Abstract: Fly ash (FA) is a complex and abundant solid waste created by humans, and has caused environmental issues, for which flotation is an effective technique employed before its comprehensive utilization. However, the complex and hydrophilic characteristics of FA particles cannot naturally fulfill the selective separation by common flotation. Therefore, this study aims to provide an insight into fluid intensification effects on flotation to achieve the enhancement of FA surface property and decarburization. The relevant effects and mechanisms are investigated, based on the measurements of zeta potential, infrared spectroscopy, contact/wrap angle, induction time, size distribution and scanning electron microscopy–energy dispersive spectrometry. Experimental results manifested that the maximum unburned carbon recovery (73.25%) and flotation rate (0.2037 s-1) were achieved with preconditioning energy inputs of 14.23 and 6.57 W·kg-1 respectively. With increasing preconditioning energy inputs, fluid intensification effects could promote the inter-particle collision/attrition, detachment of hydrophilic existence and collector adsorption on particles. Correspondingly, absorbance of some hydrophobic and hydrophilic functional groups was strengthened and weakened respectively, which accounted for the improved interfacial properties, reflected as the increased contact and wrap angles, together with declined induction time. Overall, this article revealed the positive influences of fluid intensification based preconditioning process on rendering particle surface hydrophobic and improving separation performance.

Key words: Fly ash, Waste treatment, Preconditioning energy input, Fluid intensification, Flotation, Kinetic modeling

摘要: Fly ash (FA) is a complex and abundant solid waste created by humans, and has caused environmental issues, for which flotation is an effective technique employed before its comprehensive utilization. However, the complex and hydrophilic characteristics of FA particles cannot naturally fulfill the selective separation by common flotation. Therefore, this study aims to provide an insight into fluid intensification effects on flotation to achieve the enhancement of FA surface property and decarburization. The relevant effects and mechanisms are investigated, based on the measurements of zeta potential, infrared spectroscopy, contact/wrap angle, induction time, size distribution and scanning electron microscopy–energy dispersive spectrometry. Experimental results manifested that the maximum unburned carbon recovery (73.25%) and flotation rate (0.2037 s-1) were achieved with preconditioning energy inputs of 14.23 and 6.57 W·kg-1 respectively. With increasing preconditioning energy inputs, fluid intensification effects could promote the inter-particle collision/attrition, detachment of hydrophilic existence and collector adsorption on particles. Correspondingly, absorbance of some hydrophobic and hydrophilic functional groups was strengthened and weakened respectively, which accounted for the improved interfacial properties, reflected as the increased contact and wrap angles, together with declined induction time. Overall, this article revealed the positive influences of fluid intensification based preconditioning process on rendering particle surface hydrophobic and improving separation performance.

关键词: Fly ash, Waste treatment, Preconditioning energy input, Fluid intensification, Flotation, Kinetic modeling