Project/Area Number |
05555200
|
Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
|
Allocation Type | Single-year Grants |
Research Field |
Metal making engineering
|
Research Institution | KYUSHU UNIVERSITY |
Principal Investigator |
ONO Yoichi Kyushu University, Eng., Professor, 工学部, 教授 (20037732)
|
Co-Investigator(Kenkyū-buntansha) |
MAEDA Takayuki Kyushu University, Eng., Research Associate, 工学部, 助手 (50150496)
MURAYAMA Takeaki Kyushu University, Eng., Associate Professor, 工学部, 助教授 (40112312)
|
Project Period (FY) |
1993 – 1995
|
Project Status |
Completed (Fiscal Year 1995)
|
Budget Amount *help |
¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 1995: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1994: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1993: ¥4,700,000 (Direct Cost: ¥4,700,000)
|
Keywords | Fluidized Bed / Powder Ore / Gaseous Reduction / Mathematical Model / Particle Size Distribution / Particle Shape / Unreacted-core Model / Smelting Reduction / 粉化 |
Research Abstract |
The main results of this research are as follows. 1. The measurement method of reduction rate of single hematite particle by using thermo-balance was developed for the determination of rate parameters which can be used for the reduction rate analysis in a fluidized bed. It was confirmed in experiment that the obtained rate parameters can be used for the reduction rate analysis in a fluidized bed. 2. The diffusion resistance in a particle was not able to be ignored in the case of reduction of commercial ores having the porosity of 10-20% even in the small particle of 0.15mm in diameter. On the other hand, in the case of reagent grade hematite powder having the porosity of 30%, reduction rate was controlled by chemical reaction. 3. Reduction rate of the large size samples having various shape (sphere, cylinder, and plate) was measured and rate parameters were obtained from the data. The rate parameters varied with the value of shape factor. 4. A reduction model considering the particle size distribution in a fluidized bed was developed. It was clarified in experiment that this model was effective in the case that particle segregation was significant in the bed. 5. A mathematical model considering a decrease of particle diameter by degradation and carry-out of particles from the bed during the fluidized bed reduction was developed. It was found that the reduction rate became faster apparently because of the degradation of particles. 6. Degradation of particles resulted from the reduction and the fluidization. Degradation was most significant in the fluidized bed reduction at 700゚C.
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