Developmental Scientific Research on Smelting Reduction of Pulverized Chromite Ores by The Injection into Molten Iron.
| Project/Area Number |
59850109
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
金属精錬・金属化学
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| Research Institution | Toyohashi University of Technology |
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Principal Investigator |
KAWAKAMI Masahiro Faculty of Engineering, Toyohashi University of Technology, 工学部, 助教授 (30016597)
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| Co-Investigator(Kenkyū-buntansha) |
FUJII Tetsuya Iron and Steel Research Institue, Kawasaki Steel Corporation, プロセス研究部製鋼研究室, 主任研究員
ITO Koin Faculty of Engineering, Toyohashi University of Technology, 工学部, 教授 (00023060)
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| Project Period (FY) |
1984 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥34,700,000 (Direct Cost: ¥34,700,000)
Fiscal Year 1986: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1985: ¥4,700,000 (Direct Cost: ¥4,700,000)
Fiscal Year 1984: ¥29,000,000 (Direct Cost: ¥29,000,000)
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| Keywords | chromite ore / iron melt / slag / smelting reduction / development of new process / chemical engineering analysis / kinetic analysis / 酸化クロムの溶解 / 粉体吹込み / 反応機構 / 還元速度 / 溶融スラグ |
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| Research Abstract |
Developmental scientific research on the smelting reduction of chromite ores has been carried out to produce Fe-Cr alloy, in which pulverized chromite ore was injected into molten iron and was reduced by the dissolved carbon in it.
In 20 kg scale experiments, at first, the principle of the new process was verified. The effect of temperature, ore injection rate, powder size and flow rate of carrier gas on the reduction rate was examined secondly. The results were discussed from chemical engineering view point. From the behavior of Si during the reduction process and the effect of initial Cr content on the reduction rate, the process was discussed from kinetic view point. Finally, it was revealed that the slag should be put on the melt surface to dissolve the un-reduced part of ores and reduce further there, in order to improme the reduction degree.
Small scale experiments have been carried out, in order to clarify the dissolution and reduction behavior of chromite ore into the slag. Prefe
… More
rential reduction of iron oxides and the effect of experimental conditions were revealed, when the mixture of chromite ore, graphite powder and slag was heated up to high temperature. The reduction rate of chromite bearing slag by the dissolved carbon in iron melt was examined and the reaction mechanism was discussed. The solubility of chromium oxide in the slag was determined. It was found that the solubility increase drastically when graphite powder was added to the slag. Finally, the experiment on pre-reduction and sintering of chromite ore has been carried out. The initiation temperature for the reduction of chromium oxide and the optimum heating pattern of sintering were revealed.
The smelting reduction of chromite ore has been also examined in 5 t test converter. It was revealed that the smelting reduction could proceed effectively even in the condition where the combustion of carboneceous materials by <O_2> proceeded simultaneously. The reduction rate of bottom-injected ore powder was obtained and was compared with that obtained in 20 kg scale experiments. It was found that the reduction degree was improved markedly when the ore powder was injected with <O_2> and fused at the fire spot just above the tuyere. However, an important technological problem arose, that tubings of powder conveying system was seriously attacked by the abrasive ore powders. In order to overcome the problem, a new top injection method was developed, in which the ore powder should pass through the combustion frame of pulverized coal and oxygen. Less
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Report
(2 results)
Research Products
(12 results)
