SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2019, Vol. 27 ›› Issue (11): 2771-2782.DOI: 10.1016/j.cjche.2019.02.024

• Energy, Resources and Environmental Technology • 上一篇    下一篇

Relationship between pore structure and hydration activity of CaO from carbide slag

Junqiang Zhang1, Shu Zhang2, Mei Zhong3, Zhi Wang1, Guoyu Qian1, Junhao Liu1, Xuzhong Gong1,4   

  1. 1 Key Laboratory of Green Process and Engineering, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
    2 College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China;
    3 Key Laboratory of Coal Clean Conversion & Chemical Engineering Process(Xinjiang Uyghur Autonomous Region), College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046, China;
    4 University of Chinese Academy of Sciences, Beijing 100190, China
  • 收稿日期:2019-01-01 修回日期:2019-02-18 出版日期:2019-11-28 发布日期:2020-01-19
  • 通讯作者: Shu Zhang, Xuzhong Gong
  • 基金资助:
    Supported by the National Natural Science Foundation of China (U1610101, 51422405).

Relationship between pore structure and hydration activity of CaO from carbide slag

Junqiang Zhang1, Shu Zhang2, Mei Zhong3, Zhi Wang1, Guoyu Qian1, Junhao Liu1, Xuzhong Gong1,4   

  1. 1 Key Laboratory of Green Process and Engineering, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
    2 College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China;
    3 Key Laboratory of Coal Clean Conversion & Chemical Engineering Process(Xinjiang Uyghur Autonomous Region), College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046, China;
    4 University of Chinese Academy of Sciences, Beijing 100190, China
  • Received:2019-01-01 Revised:2019-02-18 Online:2019-11-28 Published:2020-01-19
  • Contact: Shu Zhang, Xuzhong Gong
  • Supported by:
    Supported by the National Natural Science Foundation of China (U1610101, 51422405).

摘要: CaO needs to show high activity to be used as Ca-sorbent and slagging agent. Hydration activity is an important characteristic to evaluate the activity of CaO. In this study, carbide slag from polyvinyl chloride (PVC) industry was utilized as precursor for preparing high activity CaO. The roles of crystallite grain, average pore diameter (APD) and volume fraction of pore < 200 nm in diameter (VF200) in hydration activity of CaO from carbide slag (CS-CaO) were respectively investigated. The hydrolysis kinetics model of CaO shows a three-dimensional spherically symmetric diffusion model (D4), which suggests that hydration activity was mainly associated with APD and VF200 of CS-CaO with limited correlation to the crystal size. Specifically, the hydration activity of CS-CaO is increased with increasing VF200, while decreased with increasing APD. Under the invariable calcination temperature, the core-shell structure formed by the addition of graphite or CaCO3 to CS effectively inhibits the sintering of CS-CaO and improves VF200. Consequently, the hydration activity of CS-CaO increased from 22.79℃·min-1 to 27.19℃·min-1 and to 29.27℃·min-1, with addition of 5% graphite or 5% CaCO3 into carbide slag, respectively.

关键词: Carbide slag, CaO, Hydration activity, Sintering, Pore volume fraction

Abstract: CaO needs to show high activity to be used as Ca-sorbent and slagging agent. Hydration activity is an important characteristic to evaluate the activity of CaO. In this study, carbide slag from polyvinyl chloride (PVC) industry was utilized as precursor for preparing high activity CaO. The roles of crystallite grain, average pore diameter (APD) and volume fraction of pore < 200 nm in diameter (VF200) in hydration activity of CaO from carbide slag (CS-CaO) were respectively investigated. The hydrolysis kinetics model of CaO shows a three-dimensional spherically symmetric diffusion model (D4), which suggests that hydration activity was mainly associated with APD and VF200 of CS-CaO with limited correlation to the crystal size. Specifically, the hydration activity of CS-CaO is increased with increasing VF200, while decreased with increasing APD. Under the invariable calcination temperature, the core-shell structure formed by the addition of graphite or CaCO3 to CS effectively inhibits the sintering of CS-CaO and improves VF200. Consequently, the hydration activity of CS-CaO increased from 22.79℃·min-1 to 27.19℃·min-1 and to 29.27℃·min-1, with addition of 5% graphite or 5% CaCO3 into carbide slag, respectively.

Key words: Carbide slag, CaO, Hydration activity, Sintering, Pore volume fraction