Korean Journal of Metals and Materials (대한금속재료학회지)

The Korean Institute of Metals and Materials (대한금속재료학회)
권호 표지

Decarbonization Kinetics of Molten Iron by Ar+O2 Gas Bubbling

Ar+O2 혼합가스 취입에 의한 용철의 탈탄 반응속도

  • Sohn, Ho-Sang (Department of Materials Science and Metallurgy, Kyoungpook National University) ;
  • Jung, Kwang-Hyun (1Department of Materials Science and Metallurgy, Kyoungpook National University,BNG STEEL)
  • 손호상 (경북대학교 금속신소재공학과) ;
  • 정광현 (경북대학교 대학원 금속신소재공학과(현 비앤지스틸))
  • Received : 2008.10.30
  • Published : 2009.02.25
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Abstract

Molten iron with 2 mass % carbon content was decarbonized at 1823 K~1923 K by bubbling $Ar+O_2$ gas through a submerged nozzle. The reaction rate was significantly influenced by the oxygen partial pressure and the gas flow rate. Little evolution of CO gas was observed in the initial 5 seconds of the oxidation; however, this was followed by a period of high evolution rate of CO gas. The partial pressure of CO gas decreased with further progress of the decarbonization. The overall reaction is decomposed to two elementary reactions: the decarbonization and the dissolution rate of oxygen. The assumptions were made that these reactions are at equilibrium and that the reaction rates are controlled by mass transfer rates within and around the gas bubble. The time variations of carbon and oxygen contents in the melt and the CO partial pressure in the off-gas under various bubbling conditions were well explained by the mathematical model. Based on the present model, it was explained that the decarbonization rate of molten iron was controlled by gas-phase mass transfer at the first stage of reaction, but the rate controlling step was transferred to liquid-phase mass transfer from one third of reaction time.

Keywords

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