Journal of Northeastern University Natural Science ›› 2018, Vol. 39 ›› Issue (7): 985-989.DOI: 10.12068/j.issn.1005-3026.2018.07.015

• Materials & Metallurgy • Previous Articles     Next Articles

Influence of Thermal Reserve Zone Temperature in Blast Furnace on Gas Utilization Rate

MENG Fan-chao, ZOU Zong-shu   

  1. School of Metallurgy, Northeastern University, Shenyang 110819, China.
  • Received:2017-03-17 Revised:2017-03-17 Online:2018-07-15 Published:2018-07-11
  • Contact: MENG Fan-chao
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Abstract: The relationship between temperature of thermal reserve zone and the gas utilization rate of blast furnace was investigated. Considering thermodynamics and practical condition, only the reduction of ferrous oxide occurs in the thermal reserve zone. Thus, the thermodynamic analysis and kinetic analysis of reduction reactions in thermal reserve zone were carried out with standard Gibbs free energy calculation and unreacted shrinking core model, respectively. The results of thermodynamic analysis show that only when the (H2+H2O) volume fraction is smaller than 0.3, lowering temperature is effective for improving gas utilization. The kinetic analysis shows that decreasing temperature from 1273K to 1223K, the reduction rate with H2 decreases more than that with CO, showing that the influence of temperature on the reduction with H2 is greater than that with CO. For most blast furnaces, the required reduction time is somewhat longer than the burden residence time in the thermal reserve zone, which means that the reduction reactions in thermal reserve zone don’t attain their equilibria, and lowering temperature is not effective for improving gas utilization.

Key words: blast furnace, thermal reserve zone, thermodynamics, kinetics, gas utilization

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