著者

三村 均 福森 充 大谷 登蔵 菅野 卓治 Hitoshi MIMURA Mitsuru FUKUMORI Tozo OTANI Takuji KANNO 東北大学選鉱製錬研究所 東北大学工学部原子核工学科:(現)日本データスキル株式会社 東北大学大学院工学研究科:(現)日揮株式会社 東北大学選鉱製錬研究所

出版者

東北大學選鉱製錬研究所

雑誌

東北大學選鑛製錬研究所彙報 = Bulletin of the Research Institute of Mineral Dressing and Metallurgy, Tohoku University (ISSN:0040876X)

巻号頁・発行日

vol.35, no.1, pp.19-26, 1979-09-22

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The distribution of cesium ion and the properties of ion exchange was studied in various kinds of zeolites, i.e. synthetic mordenite, natural mordenites and clinoptilolites. The distribution coefficients of cesium (K_<Cs>) exceeded 10^3 even in acidic region (pH~1), though the K_<Cs> values somewhat decreased with increasing acidity. The dynamic properties of ion exchange were examined by zeolite-column process and the break-through curves were obtained at different flow conditions. The break-through capacity, the total capacity and the column utilization increased with the increase in column temperature and with the decrease in the flow rate. Heat treatment resulted in an increase in the strength of zeolites, which was desirable for handling them. The zeolites heated at 300℃ and 500℃ increased in their total capacity of ion exchange of Cs and the granulated zeolites heated at 500℃ improved in its exchange rate and column utilization.

著者

八嶋 三郎 荒井 豊 堀田 浩充 橋本 等

出版者

東北大學選鉱製錬研究所

雑誌

東北大學選鑛製錬研究所彙報 = Bulletin of the Research Institute of Mineral Dressing and Metallurgy, Tohoku University (ISSN:0040876X)

巻号頁・発行日

vol.40, no.2, pp.191-198, 1985

著者

南部 松夫 岡田 広吉

出版者

東北大學選鉱製錬研究所

雑誌

東北大學選鑛製錬研究所彙報 = Bulletin of the Research Institute of Mineral Dressing and Metallurgy, Tohoku University (ISSN:0040876X)

巻号頁・発行日

vol.19, no.1, pp.1-12, 1963-10-28

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The bedded manganese oxide deposits of Iwasaki distrct, Aomori Prefecture occur in most cases in tuffaceous sandstone of the upper Miocene age. The mother rock of these deposits is slightly affected by the hydrothermal alteration, and the ore is characterized by the mineral composition of a single manganese mineral, todorokite. The mineral is identified mainly by the X-ray powder method and chemical and differential thermal analyses. The chemical formula is (Mn^<2+>_<0.58> Ca_<0.09> Mg_<0.20> Ba_<0.04>)_<0.90> Mn^<4+>_<3.06> O_<7.00>・2.1 H_2O which agrees well with Mn^<2+>Mn_3^<4+>O_7・2-xH_2O given by L.T.Larsen in 1962.

著者

梅津 良昭 李 自強 徳田 昌則

出版者

東北大學選鉱製錬研究所

雑誌

東北大學選鑛製錬研究所彙報 = Bulletin of the Research Institute of Mineral Dressing and Metallurgy, Tohoku University (ISSN:0040876X)

巻号頁・発行日

vol.47, no.1/2, pp.58-65, 1991-12-27

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Thiourea leaching of silver sulfide was studied in weakly acidic sulfate solutions containing ferric sulfate as a moderate oxidant. In the presence of ferric ions, the sulfide sulfur was converted into elemental sulfur and the silver was extracted as its thiourea complex ion, Ag(NH_2CSNH_2)_3^+. In the leaching without oxidant, silver sulfide was leached according to the H_2S forming reaction, where the elimination of H_2S from the leach liquor, for instance by nitrogen gas flow, significantly favored the leaching. In the both cases, the presence of thiourea was necessary for the extraction of silver from the sulfide. The moderate leaching conditions such as fairly low acid concentration at a level around 0.06mol/l and the operation temperature not higher than 50℃, and a high concentration of thiourea promoted the silver extraction mainly due to the increased stability of the thiourea complex ion of silver. It was also observed that silver sulfide was easily extracted in the oxidative thiourea leaching where sulfide ore consisting mainly of pyrite, arsenopyrite, stibnite and chalcopyrite coexisted.

著者

李 正吉 伊藤 公久 徳田 昌則

出版者

東北大學選鉱製錬研究所

雑誌

東北大學選鑛製錬研究所彙報 = Bulletin of the Research Institute of Mineral Dressing and Metallurgy, Tohoku University (ISSN:0040876X)

巻号頁・発行日

vol.44, no.2, pp.237-245, 1989-03-25

著者

南部 松夫 伊藤 建三

出版者

東北大學選鉱製錬研究所

雑誌

東北大學選鑛製錬研究所彙報 = Bulletin of the Research Institute of Mineral Dressing and Metallurgy, Tohoku University (ISSN:0040876X)

巻号頁・発行日

vol.16, no.1, pp.1-8, 1960-08-25

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The crystallization process of poorly crystallized ferric oxide formed by the dehydration of three α-type limonites obtained from different localities was studied by means of X-ray powder method. The results are as follows : 1) α-type limonite changes into a mixture of poorly crystallized hematite and amorphous ferric oxide by its thermal decomposition in the temperature range 390-405℃. These two heated products arise from crystalline goethite and amorphous ferric oxide hydrate contained respectively in original limonite. 2) Variations in the degree of crystallization of hematite changed from limonite by heating depend on the difference in the crystallinity of original goethite. 3) At low temperature from 350 to 550℃, the transformation of amorphous ferric oxide into hematite crystallite is predominent, compared with the growth of hematite crystallite. 4) The hematite crystallite formed at low temperature has a tendency of the two dimensional lattice up to about 750℃, and then grows gradually with rising temperature. 5) The crystallization process of poorly crystallized hematite and amorphous ferric oxide formed by thermal dehydration of α-type limonite may be shown as follows : [numerical formula]

著者

芦塚 正博 大谷 正康 Masahiro ASHIZUKA Masayasu OHTANI

出版者

東北大學選鉱製錬研究所

雑誌

東北大学選鉱製錬研究所彙報 (ISSN:0040876X)

巻号頁・発行日

vol.25, no.1, pp.53-65, 1969-10

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The resistance ΔR, which exists at the electrode-electrolyte interface and is dependent to the frequency used, is an important factor to be considered besides the resistance of the solution in the conductivity measurement of the electrolyte by alternating current. The present authors discussed in detail on the source of the resistance ΔR and its effect on the electrical conductivity. The results obtained are as follows : 1) Warburg's equation, Rs=a/√<ω>, Cs=b/√<ω>, is only available to the system, in which the slagmetal interface is at equilibrium potential and the exchange current density is large. Here, Rs, Cs, and W are the resistance, capacity and the frequency in radiance per second, respectively. 2) ΔR is not directly proportional to l/√<ω> and might be attributed to the surface roughness of the solid electrode. 3) The apparent activation energy of the conductivity is clearly affected by the frequency for melts with high conductivity such as Na_2O-SiO_2 melts.

著者

三本木 貢治 Koji SANBONGI

出版者

東北大學選鉱製錬研究所

雑誌

東北大学選鉱製錬研究所彙報 (ISSN:0040876X)

巻号頁・発行日

vol.8, no.1, pp.39-46, 1952-06

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The author had already performed some investigations on the reduction equilibrium of iron oxides and proposed the reduction equilibrium diagram of Fe-C-O system. But the equilibrium on systems of Fe_3O_4-liquid oxide-CO/CO_2 mixed gas and wustite-liquid oxide-CO/CO_2 mixed gas, and the relation between oxygen pct. in liquid oxide and CO/CO_2 mixed gas had not been measured. These relations were shown by concluded lines in the diagram. Recently these equilibrium were measured by Darken and Gurry and the relations between oxygen pct. in wustite and CO/CO_2 mixed gas were clecked from the view point of the statistical thermodynamics by Takeuchi and Igaki. Referring to these results, the author corrected the reduction equilibrium diagram of Fe-C-O system, then established the reduction equilibrium diagram of Fe-H-O system by the calculation.