1993 Fiscal Year Final Research Report Summary
新脱ガス法(真空吸引脱ガス法)による融体の高純度化に関する研究
| Project/Area Number |
04555158
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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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 | NAGOYA UNIVERSITY |
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Principal Investigator |
SANO Masamichi NAGOYA UNIVERSITY,DEPARTMENT OF MATERIALS PROCESSING ENGINEERING,PROFESSOR, 工学部, 教授 (70023174)
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| Co-Investigator(Kenkyū-buntansha) |
KUDO Ichiro NIPPON STEEL CORP.MURORAN WORKS,EQUIPMENT TECHNOLOGY DIV., SENIOR MANAGER, 室蘭製鉄所・設備部, 部長代理
MIZUKAMI Yoshimasa NIPPON STEEL CORP.CENTRAL R&D BUREAU,CHIEF RESEARCHER, 技術開発本部・名古屋技術研究部, 主幹研究員
YAMAMOTO Kimiji TYK CORP.RESEARCH&DEVELOPMENT CENTER,GENERAL MANAGER, 研究所, 所長
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| Project Period (FY) |
1992 – 1993
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| Keywords | MOLTEN METAL / HIGH PURITY METAL / VACUUM DEGASSING / DEHYDROGENATION / DENITROGENATION / DEOXIDATION / DECARBURIZATION / POROUS MATERIAL |
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| Research Abstract |
A vacuum suction degassing method (VSD method) has been proposed and applied to remove gas-forming impurities in molten metal. The melt is separated from the outside by means of a porous partition wall permeable to gas and impermeable to the melt, and outside is kept at a reduced pressure. Then, the gas-forming impurities gasify at the partition wall-melt interface and the formed gas is sucked through the wall to the outside. Thus, the removal of the impurities from the molten metal is enhanced.
Experiments of decarburization, denitrogenation of molten iron have been performed in the ranges of low concentrations by immersing a porous refractory tube into the melt. The decarburization proceeds by a reaction between the carbon in the melt and the refractory oxide, such as Al_2O_3, SiO_2, etc. The carbon concentration of the melt decreases down to a very low value of a few ppm, while the oxygen concentration is kept below 50ppm. The rate of decarburization with an Al_2O_3-SiO_2 tube is muc
… More
h higher than that with an Al_2O_3 tube. In crease in gas permeability of the porous tube makes the decarburization rate larger. It is shown that the vacuum suction degassing method can greatly increase the decarburization rate of molten iron. The VSD method has been applied to denitrogenate molten iron. The rate of denitrogenation increases by the simultaneous decarburization. The chemical reaction rate constant for the denitrogenation at the porous tube-molten iron interface is almost equal to that obtained previously by gas blowing onto the melt surface.
The deoxidation of molten copper with graphite has been studied by applying the VSD method. The deoxidation rate decreases due to suction of CO gas and hence lack of stirring by the CO bubbles. However, the minimum oxygen concentration decreases to a lower value than that obtained without using the VSD method.
The VSD method is also shown to be effective in dehydrogenating molten iron and molten aluminum. It is found that the dehydrogenation of molten iron is controlled by the liquid phase and the gas phase mass transfer and that of molten aluminum by the liquid phase mass transfer.
A test of practical application could not have been carried out and is the subject of a future study. Less
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