Thermal performance and reduction kinetic analysis of cold-bonded pellets with CO and H2 mixtures

  • Rong-rong Wang
  • Jian-liang Zhang
  • Yi-ran Liu
  • An-yang Zheng
  • Zheng-jian Liu
  • Xing-le Liu
  • Zhan-guo Li


Cold-bonded pellets, to which a new type of inorganic binder was applied, were reduced by H2–CO mixtures with different H2/CO molar ratios (1:0, 5:2, 1:1, 2:5, and 0:1) under various temperatures (1023, 1123, 1223, 1323, and 1423 K) in a thermogravimetric analysis apparatus. The effects of gas composition, temperature, and binder ratio on the reduction process were studied, and the microstructure of reduced pellets was observed by scanning electron microscopy–energy-dispersive spectrometry (SEM-EDS). The SEM-EDS images show that binder particles exist in pellets in two forms, and the form that binder particles completely surround ore particles has a more significant hinder effect on the reduction. The reduction equilibrium constant, effective diffusion coefficient, and the reaction rate constant were calculated on the basis of the unreacted core model, and the promotion effect of temperature on reduction was further analyzed. The results show that no sintering phenomenon occurred at low temperatures and that the increasing reaction rate constant and high gas diffusion coefficient could maintain the promotion effect of temperature; however, when the sintering phenomenon occurs at high temperatures, gas diffusion is hindered and the promotion effect is diminished. The contribution of the overall equilibrium constant to the promotion effect depends on the gas composition.


cold-bonded pellets inorganic binder reduction fraction reduction kinetic model sintering phenomenon 


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This work was financially supported by the National Key Research and Development Program of China (2017YFB0304300 and 2017YFB0304302) and the 111 Project (No. B13004).


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Copyright information

© University of Science and Technology Beijing and Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Rong-rong Wang
    • 1
  • Jian-liang Zhang
    • 1
  • Yi-ran Liu
    • 2
  • An-yang Zheng
    • 1
  • Zheng-jian Liu
    • 1
  • Xing-le Liu
    • 1
  • Zhan-guo Li
    • 1
  1. 1.School of Metallurgical and Ecological EngineeringUniversity of Science and Technology BeijingBeijingChina
  2. 2.School of Chemical EngineeringUniversity of New South WalesSydneyAustralia

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