著者

久保 善博

出版者

一般社団法人 日本鉄鋼協会

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.109, no.1, pp.25-32, 2023 (Released:2022-12-31)

参考文献数

13

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The aim of this project was to learn roles of titanium oxide (TiO2), an impurity contained in iron sand, in the products resulting from traditional iron making processes, tatara operations. For this purpose, iron sand was collected using two different mineral processing methods from four different locations in the Chugoku area of Japan, and these samples were used to run small-scale tatara experiments. Iron sand collected with traditional gravity separation method contained 8 to 12% TiO2, while iron sand collected with modern magnetic separation method contained less than 5% TiO2. When gravity-separated iron sand was used in a tatara under strong reducing conditions, zuku (cast iron) flowed out of the tatara. In contrast, magnetically collected iron sand failed to produce zuku, but did produce raw steel at the bottom of the furnace. Further, even magnetically isolated iron sand could produce zuku when it was supplemented with ilmenite, a titanium-iron oxide containing mineral. The results show that TiO2 plays a key role in producing cast iron in tatara operations, and the fact that Akome iron sand is known to produce cast iron as it contains higher levels of TiO2. In contrast, Masa iron sand which is known to produce steel (tamahagane) contains much less TiO2 and hence is not suitable to produce cast iron. These observations agree with historical descriptions stating that pre-modern tatara operators knew to add iron sand from a specific locality (which is rich in TiO2) to Masa-type iron sand to produce cast iron.

著者

久保 善博 久保田 邦親

出版者

たたら研究会

雑誌

たたら研究 (ISSN:02887916)

巻号頁・発行日

no.50, pp.29-39, 2010-12

著者

久保 善博 佐藤 豊 村川 義行 久保田 邦親

出版者

社団法人日本鉄鋼協会

雑誌

鐵と鋼 : 日本鐡鋼協會々誌 (ISSN:00211575)

巻号頁・発行日

vol.91, no.1, pp.83-90, 2005-01-01

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The Japanese traditional steel making method which manufactures steel "Kera" or plg iron "Zuku" from iron sand and charcoal is so called "Tatara" steel making process The influence of the loading ratio of iron sand to charcoal on the "Tatara" steel making was investigated In the case of the loading ratio is equal to 1, high carbon steel "Kera" was produced at the high yield accompanied with viscous slag "Noro" In the meantime, in the case of the loading ratio is equal to 15, the carbon content of the produced steel "Kera" was low at the low yield accompanied with a lot of low viscous slag "Noro" In the case of low loading ratio, so called "light charge", iron sand was well deoxidized and carbonized in the furnace and became to high carbon steel "Kera" at the high efficiently In that case, the slag "Noro" became to viscous one because of the reduction of FeO content on the contrary, in the case of high loading ratio, so called "heavy charge", the deoxidization of iron sand was insufficient and most of iron sand was discharged as a slag "Noro" to the outside of the furnace As the result, produced steel "Kera" yield lowered During the "heavy charge" operation, the composition of the slag "Noro" became FeO-rich, and then the fluidity of the slag "Noro" increased It was clarified that the controlling of the loading ratio was an important factor which affected both to the quality and productivity of steel "Kera" and the fluidity of slag "Noro" on "Tatara" steel making process