CO-CO_2 混合ガスによる酸化鉄ペレットの段階ごと還元

概要

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A series of reduction experiments was made in which hematite pellets were reduced step-wise from Fe_2O_3 to Fe_3O_4, Fe_3O_4 to Fe_xO, and finally Fe_xO to Fe by CO-CO_2 mixtures of appropriate compositions in the temperature range from 800 to 1050℃. The hematite pellets were made of pyrite cinder and the porosity was approximately 13%. Experimental data for each reduction step were analyzed in terms of the mixedcontrol kinetics based on the isothermal unreacted-core model. The results obtained are summarized as follows : (1) Rate constants for the reduction steps of Fe_2O_3 to Fe_3O_4, Fe_3O_4 to Fe_xO, and Fe_xO to Fe are expressed, respectively, by following equations : kc_m=exp(7.768-18.92×10^3/RT) (cm/sec) kc_w=exp(12.18-28.80×10^3/RT) (cm/sec) kc_<Fe>=exp(12.70-29.91×10^3/RT) (cm/sec) (2) Labyrinth factors of the reduction product layers of Fe_3O_4, Fe_xO, and Fe are expressed, respectively. by following equations : log_<10>ζ_m=0.382×10^<-2>T-5.352 (-) log_<10>ζ_w=0.159×10^<-2>T-2.467 (-) log_<10>ζ_<Fe>=0.124×10^<-2>T-1.734 (T≧1173K) (-) log_<10>ζ_<Fe>=0.102×10^<-1>T-12.25 (T<1173K) (-) (3) Reduction curves calculated for each reduction step by using the rate parameters based on the unreacted-core model are in satisfactory agreement with experiments.
社団法人日本鉄鋼協会の論文
1977-06-01