| Project/Area Number |
01850148
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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 | Tohoku University |
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Principal Investigator |
SUITO Hideaki Tohoku Univ. SENKEN Professor, 選鉱製錬研究所, 教授 (70030054)
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| Co-Investigator(Kenkyū-buntansha) |
HIDAKA Chikara Taenaka Mining Co., Managing Director Ltd. Hazaki works, 波崎工場, 工場長
KUDO Setsuko Tohoku Univ. Senken Research Associate, 選鉱製錬研究所, 助手 (20195457)
INOUE Ryo Tohoku Univ. SENKEN Lecturer, 選鉱製錬研究所, 講師 (70111309)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1990: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1989: ¥6,200,000 (Direct Cost: ¥6,200,000)
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| Keywords | Flux / Iron ore / Iron oxide / Purification / Impurity / Leaching / Recrystallization / Partition coefficient / 分配 / マンガン / アルミニウム / チタン |
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| Research Abstract |
Using the Na_2O-B_2O_3 flux, the impurities in fine grained iron ore were removed by the flux leaching (850-950^ﾟC) and recrystallization methods (1400-1450^ﾟC). The impurities that were isolated and those on the surface of the ore could be removed by the former method. The later method was effective for the removal of inclusions existing inside the grain. The concentrations of impurities for Si, Al, Ca, Mg, Mn and V decreased with increasing temperature between 850 and 1450^ﾟC. These results were explained by the increase in the amount of recrystal lized iron oxide as well as the break up of a fine ore with an increase in temperature.
It was found that the partition coefficients of the trace elements between Na_2O-B_2O_3 flux and alpha -Fe_2O_3 crystal were indispensable in order to clarify the impurity behavior in purification of alpha -Fe_2O_3 by recrystallization method. The experiments on the Mn, Al and Ti partitions between alpha -Fe_2O_3 crystal and fluxes have been carried out as a function of temperature and flux composition. Alpha -Fe_2O_3 crystal grew not by clustering of fine Fe_2O_3 particles but by Ostwald ripening mechanism. Mn, Al and Ti were included in equilibrium with flux by adsorption on alpha -Fe_2O_3 surface during crystal growth. No diffusion mechanism was involved in the present experiment. The partition coefficients of Mn, Al and Ti between alpha -Fe_2O_3 crystal and Na_2O.2B_2O_3 flux at 1000^ﾟC were 0.8, 0.02 and 1, respectively. The temperature dependence of partition coefficient of Mn was found to be negative, while that of Al and Ti was positive. Mn was present as Mn^<3+> in alpha -Fe_2O_3 crystal. Fe and Mn in flux were present as Fe^<3+> and Mn^<2+>, respectively.
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