著者

花野 峰行

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.9, pp.214-222, 2017-09-01 (Released:2017-09-08)

参考文献数

24

被引用文献数

1

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The Matsukawa geothermal power station has been in commercial operation since 1966. Its geothermal reservoir was discovered by chance, by drilling of hot spring wells by the local administration in 1952. Japan Metals & Chemicals (JMC) noticed this phenomenon and started exploration for a geothermal power development in 1956. Then, JMC and Geological Survey of Japan (GSJ) started collaborative study in 1958. The biggest technical challenge for success in Matsukawa was a decision of drilling target depth for steam production and a casing shoe depth to stop in-flow of shallow cold water. It was examined through measurements of water levels in three exploration wells, borehole temperature profiles and flow rates of rivers. Geological and geophysical studies by GSJ helped this study. Owing to this study, the 1st production well succeeded to produce dry steam in 1964 and led to a success in the first commercial scale geothermal power development in Japan.

著者

佐々木 順悠 村上 進亮

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.8, pp.207-213, 2017-08-01 (Released:2017-08-31)

参考文献数

8

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Mineral prices hit their ceilings and started fluctuating. It forced resource-related companies to reassess their assets. In order to secure the stable supply of resources, it is important for Japan, which is a resource-importing country, to keep an eye on the changes in strategies of resource-related companies, especially mining giants that dominate the global production of various minerals. There are some studies focusing only on risk management at an individual mine level and fluctuation in mineral prices, but few studies focus on asset management of the mining giants as an entity. The purpose of this paper is to analyze and understand the asset management strategies of the mining giants. All assets of the giants, such as mines, smelters and refineries are considered as risky assets, calculating the optimal portfolio under the “Modern Portfolio Theory”. By comparing the derived optimal portfolio with the actual one, we conclude that the mining giants' asset management strategies are almost optimal. We also found out which asset will be on sale from each company, which can be useful for Japanese companies increasing the share in overseas mines.

著者

小林 幹男

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.8, pp.193-206, 2017-08-25 (Released:2017-08-26)

参考文献数

53

被引用文献数

4

---

Recently the treatment of mine drainage, especially acid mine drainage (AMD) is attracting a lot of attention, including the passive treatment that is a cost-effective and energy efficient process. In such a process, the natural geochemical reaction, gravitational flow, bacteria metabolism, etc, are utilized for the active treatment, enabling continuous addition of chemical reagents and maintenance of mechanical facilities, and so on. For a long time, the development of the passive treatment was mainly carried out in North America and Europa, thus, much useful knowledge is cultivated and many experimental and actual sites are operated in these area. In this paper, the useful knowledge, information and instances related to the passive treatment are reviewed. The performance of sulfate reducing bacteria (SRB) is very important for the treatment of the mine drainage from non-ferrous mine sites. Thus, the matters related with SRB, that is, the reaction, the reactor and the operation are also described in detail.

著者

高野 雅俊 尾崎 佳智 浅野 聡 馬場 雄三 久保田 富生子 後藤 雅宏

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.8, pp.188-192, 2017-08-25 (Released:2017-08-19)

参考文献数

9

---

Extraction behavior of cobalt from sulfate media containing excess manganese by mixtures LIX63 and several amines was investigated. The addition of amines shifted cobalt extraction isotherm to higher pH region in all case. The degree of the pH isotherm shifts depended on the basicity of each amine in the case of manganese however did not depend on it in the case of cobalt. The separation ability of cobalt from manganese was highest in case of LIX63 and primary amine system.

著者

荒牧 憲隆 A.K.M. Badrul Alam 玉村 修司 上野 晃生 村上 拓馬 金子 勝比古

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.7, pp.173-181, 2017-07-01 (Released:2017-07-28)

参考文献数

33

---

Peat from highly organic soil is abundant in Northern Hokkaido, Japan. In the past, peat was used in various applications in Japan, such as an artificial culture of soil, as a fertilizer for gardening, and as an energy resource. However, peat is not used by the modern energy and manufacturing sectors in Japan because it has a high moisture content and low calorific value, which lowers its value as a resource considering its material characteristics and handling difficulties. Furthermore, large amounts of peat are generated at the construction sites in this area, and they are difficult to be reused at their generation sites because peat is a very soft soil and not suitable for construction work. Recently, many Japanese research institutions have been carrying out research and development on renewable energy resources including biomass energy. In Hokkaido, there are many biogas plants for methanizing biomass derived from livestock excrement or food waste. Thus, peat which is high in organic matter could potentially be used as an energy resource. In this study, we investigated the potential of utilizing peat as an energy resource for biogenic methane production in regional cities of Northern Hokkaido, while considering both its material characteristics and resource circulation. Batch tests using a hydrogen peroxide solution were performed on peat and silty soil to estimate the quantity of low-molecular-weight organic acids and the producing potential for biogenic methane gas. The oxidative decomposition of the peat produced a high yield of low-molecular-weight organic acids that were used as substrates for methanogenic microorganisms. In addition, a novel resource circulation method was proposed for peat in order to use it as an energy resource. Moreover, the energy resources problem in Northern Hokkaido was discussed in association with geographical parameters and the construction recycling system in Japan.

著者

徳重 晃大 森 康平 大上 悟 松島 寛 鈴木 一成 中野 博昭

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.7, pp.165-172, 2017-07-01 (Released:2017-07-21)

参考文献数

15

被引用文献数

5

---

Cu electrolysis was performed using low-grade copper anode with purity 78.7 mass% at a anode current density of 200 A・m-2 in an unagitated sulfate solution containing 0.596 mol・dm-3 of Ni2+ ions as impurity at 60 ℃, and the structure of anode slime before and after passivation was analyzed. The highly-concentrated Sb, Pb and Ag were dispersed in copper anode before electrolysis. The passivation occurred at short time of 17.7 hours in the case of low-grade copper anode, and it occurred at shorter time of 11.4 hours in the solution containing Ni2+ ions as impurity. At normal dissolution of copper anode, copper parent phase dissolved in the form of dendrite and the framework of anode slime was composed of remained Cu-Ni-Sb-Sn-As compound. Cu2S and single phase of Ag and Pb were observed around this framework. At passivation, Cu, Ni and Sn dissolved from the slime framework composed of Cu-Ni-Sb-Sn-As compound, resulting in formation of Sb condensed phase. These Cu-Ni-Sb-Sn-As compound, Sb condensed phase, Cu2S compound around the slime framework, Ag and needle-shaped PbO dotted in the whole slime suppressed the diffusion of Cu2+ ions, as a result, CuSO4 was formed at interface between the slime and copper substrate. The passivation occurred at slime thickness of approximately 500μm in Ni2+-free solution, while it occurred at slime thickness of approximately 300μm in solution containing Ni2+ ions. This indicates that the passivation do not depend on only the thickness of slime. The thickness of CuSO4 formed at passivation in Ni2+-free solution was almost identical with that from the solution containing Ni2+ ions. In solution containing Ni2+ ions, the passivation occurred at less thickness of slime, showing that CuSO4 is easy to be formed in the vicinity of copper substrate due to decrease in solubility of CuSO4 and diffusion coefficient of Cu2+ ions.

著者

畠山 信夫 清水 賀之 益山 忠

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.7, pp.157-164, 2017-07-19 (Released:2017-07-19)

参考文献数

8

被引用文献数

2

---

The flow through annuli is encountered in drilling operation, in which drilling mud flows between the borehole wall and the drilling pipe. Some drilling muds, depending on their prepared materials, exhibit nonNewtonian characteristics and in many cases may be regarded as pseudoplastic fluids. This study examines the dimensionless flow rate defined by Fredrickson and Bird (Fredrickson and Bird, 1958) on pseudoplastic fluid laminar flow in concentric annuli. A new approximation function is derived to evaluate the viscosity factor, also easy to use without numerical procedures. The function is more precise than the one, which was previously shown by the authors (Masuyama and Hatakeyama, 2003). Further, a new scheme is proposed to evaluate the characterizing coefficients, such as the pseudoplastic viscosity and the rheology constant using flow data. Furthermore, generalized formulas of the Reynolds number and the pipe friction coefficient for pseudoplastic fluid are shown for concentric annuli in order to calculate the pressure drop. They are extendable in the case of circular pipes, also parallel plates.

著者

中村 大樹 山本 英和 田中舘 悠登 羽原 俊祐 小山田 哲也

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.7, pp.151-156, 2017-07-01 (Released:2017-07-08)

参考文献数

6

---

The effect of fine sand of blast-furnace slag (SBFS) on freeze-thaw resistance, sulfate resistance, and sulfuric acid resistance in mortar whose aggregate is replaced in part or in full with blast furnace slag (SBFS) was investigated. Evaluation carried out on small test specimens confirmed that freeze-thaw resistance, sulfate resistance, and sulfuric acid resistance all improve as the SBFS substitution rate increases. However, increased porosity with a larger proportion of pores sized 50 nm or larger was also observed. In the case of the use of molten slag from municipal solid waste (SMSW), no improvement in freeze-thaw resistance was observed with increases in SBFS substitution rate.

著者

川﨑 了

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.131, no.5, pp.155-163, 2015-05-01 (Released:2016-01-01)

参考文献数

84

被引用文献数

3

---

New ground improvement technologies using microbial functions have attracted attention recently both within and outside Japan. In this review paper, an outline of the present status of ground improvement technologies using microbial functions is presented. First, the advantages of ground improvement technologies using microorganisms are described. Second, previous studies on ground cementing technologies using calcium carbonate, silica, or calcium phosphate compounds, which are biominerals and representative eco-friendly cement materials in nature, are explained after being classified into three chapters. The main conclusions of the present review are as follows: most of the previous studies used calcium carbonate as the cement material; the studies were conducted mainly in the laboratory; the techniques fall one-step short of practical use stages. Finally, studies related to the usage of waste and applied to natural beachrock formations are presented as future prospects; similar to the ground improvement technologies mentioned above, these studies may lead to unprecedented new understanding, discoveries, and development through cooperation between microbiology and geotechnical engineering fields in the future.

著者

Le Trung TUYEN 大賀 光太郎 井清 武弘

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.6, pp.140-150, 2017-06-01 (Released:2017-06-29)

参考文献数

17

被引用文献数

2

---

2004 年5 月にホンタイ炭鉱で自然発火が発生して以降,ベトナムの四カ所の無煙炭炭鉱と一カ所の亜瀝青炭炭鉱で自然発火が続発している。これらに対処するため,筆者等は断熱環境下で石炭の酸化発熱試験ができる装置を使用して,各炭鉱の石炭試料について酸化発熱特性の試験を行っている。これらのデータについて実際に自然発火を発生している炭鉱の試料に注目してみると,150 ℃以下の低温領域の酸化反応速度が他の自然発火を発生していない炭鉱の石炭試料に比較して大きいことを見出した。即ち,低温域における石炭の酸化反応速度が自然発火の発生と深い関係があるという結論を得た。既存の自然発火性評価方法との比較も試みた。

著者

木下 尚樹 氏家 勲 河合 慶有 川口 隆 安原 英明 長江 俊勝

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.6, pp.132-139, 2017-06-01 (Released:2017-06-23)

参考文献数

13

被引用文献数

12

---

Industrial waste generated in the domestic paper industry in Japan was 5.1 million tons in 2015, and after reduction and recycling, 152 thousand tons of the waste was consequently disposed. Organic sludge (paper sludge), which occupies two-thirds of the industrial waste generated in the paper industry, is incinerated for the purpose of volume reduction and thermal recycling, and then it becomes paper sludge ash (PS ash). PS ash is recycled as aggregate, roadbed material in the civil engineering field and cement raw material, but it is necessary to further expand the application and reduce the final disposal amount. From the above background, in this research, the strength characteristics, the durability performance and the environmental impact of low carbon concrete produced by reducing cement usage to 45% by using PS ash as admixture in addition to fly ash and blast furnace slag fine powder, were investigated. Experimental results show that the low carbon concrete produced in this research has long term strength development, and that PS ash does not contribute to long term strength. Moreover, the clay mineral contained in the PS ash has an effect of reducing drying shrinkage by water retention and expansion. With respect to durability performance, neutralization is promoted by decreasing the total cement amount, while salt tolerance resistance is improved. Frost damage resistance tends to decrease. The elution amount of toxic substances is less than the soil environmental standard value.

著者

岩野 圭太 永江 純一 福井 勝則 羽柴 公博

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.6, pp.123-131, 2017-06-01 (Released:2017-06-19)

参考文献数

24

被引用文献数

1

---

Although blasting is a quite efficient and economical excavation method, it is rarely applied to tunnel projects close to residential areas due to its environmental impacts, especially with regard to vibration and noise. Two key controls used to mitigate the occurrence of noise and vibration due to blasting are the use of small instantaneous explosives charges and the use of precise delay times to initiate the blast design sequence. An advanced electronic detonator, which has its precision of 0.01% of designed delay time and has made it possible to achieve precise initiation control in blasting, was introduced and used in a tunnel construction site in Japan. Testing of the delay times during blasting was carried out, the test results revealed the specific features and performance of the detonator to control the blasting vibration especially within a short distance of the tunnel face. In previous studies, several ways of simulating blasting waveforms were used. One of these, the Monte Carlo method, in which the production wave was reproduced by superposing a single wave had the potential to give good predictions of the production waves that might occur. Therefore, in this study, a similar way of simulating production waves was carried out. Section peaks in the production waveforms correspond with the detonation of each blasthole. These section peaks were found to follow the Weibull distribution, even though the section peaks might be influenced by amount of explosives, drill alignment, and geological inhomogeneity etc. More detailed simulation with consideration of difference in travel time and the change of the Weibull parameters with distance gives further precise results compared with the real production waves. This study leads more precise method of predicting production waves and of optimum blasting design.

著者

制野 友樹 蟹江 澄志 村松 淳司

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.6, pp.116-122, 2017-06-01 (Released:2017-06-12)

参考文献数

43

被引用文献数

2

---

Cerium-doped barium zirconate (Ce-doped BaZrO3) fine particles with high crystallinity was prepared by a hydrothermal reaction using barium hydroxide, CeCl3, and a Zr-triethanolamine complex. Characterization of the Ce-doped BaZrO3 particles revealed that utilization of the water-stable Zr-triethanolamine complex was an efficient way to introduce cerium ions into the BaZrO3 perovskite crystal structure. The three-way catalytic activity of the Ce-doped BaZrO3 for an exhaust gas conversion reaction was investigated under a stoichiometric condition (CO 0.5%, C3H6 400 ppm, NO 500 ppm, O2 0.49%, H2 0.17%, CO2 14%, H2O 10% in N2). The Ce-doped BaZrO3 exhibited a remarkable low temperature NOx cleaning performance when the Ce-doped BaZrO3 was applied as an alternative for an Al2O3 support.

著者

片岡 みなみ 包 添書 羽柴 公博 福井 勝則

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.6, pp.107-115, 2017-06-01 (Released:2017-06-06)

参考文献数

28

被引用文献数

3

---

The effect of water on the mechanical properties of rocks, such as strength and Young's modulus, has been investigated in many studies. To understand the mechanism of the effect of water on the mechanical behavior of rocks, not only these mechanical properties but also the stress-strain curve, which is one of the most basic data showing the mechanical behavior, should be focused on, and the change of the stress-strain curve with the different water conditions is needed to be known. In this study, the effect of water saturation on the uniaxial compressive strength and the stress-strain curve of rocks was investigated. The uniaxial compression test with alternating loading rate was performed using Sanjome andesite, Tage tuff, Kimachi sandstone and Akiyoshi marble. Inada granite was used for the uniaxial compression test with constant loading rate. The tests were conducted under various water conditions: oven-dried, vacuum-dried, air-dried, air-dried for one day, immersed in water and watersaturated conditions. The test results showed that the stress-strain curve of the andesite, tuff, sandstone and granite changed with the water saturation. On the other hand, the effect of water saturation on the stress-strain curve of the marble was not observed. From the test results, the increase in strength due to decrease in water saturation was discussed. A shift of the peak strength point with the water condition change was investigated, and the relation between the stress-strain curves under the different water conditions was considered based on it.

著者

廣岡 知 山口 達也 渡部 利文 山本 順也 城代 邦宏 保田 尚俊 塚田 和彦 小池 克明 朝倉 俊弘

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.5, pp.98-106, 2017-05-01 (Released:2017-05-31)

参考文献数

12

---

In addition to hydrological characterization of water-sealed type underground rock caverns, their mechanical stability is constantly monitored by measuring several properties, such as earthquake-induced vibration, strain, and tilt. Among them, tilt measurement is the most accurate monitoring method for rock deformation because of the tiltmeter's high resolution of 10-9 rad, which enables the detection of minute deformations caused by earth tide, rock responses to earthquake, change in atmospheric pressure, and artificial disturbance by operation. This study aimed to correctly extract these responses from long-term tilt data measured by a high precision tiltmeter at the Kushikino station and clarify the mechanism of tilt change as a result of deformation of rock mass. Tilt changes due to a small change in the gas phase pressure at the top of the rock cavern, approximately 10 kPa pressure fluctuation, were analyzed and discussed. The gradient response due to the gas pressure change was extracted from the measurement data by BAYTAP-G, and its magnitude was identified as 2 to 8 nrad, which was almost the same tilt response magnitude observed at an issuance of stored crude oil. This tilt response to the increase in tank gas pressure was numerically confirmed to originate from minute elastic deformation of rock masses, by using finite element method. Because fluctuation of the gas phase pressure can be continuously monitored, the effectiveness of tilt measurement was proved as a minute strain sensor for deformation of the water-sealed type underground rock cavern.

著者

早野 明 板倉 賢一

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.4, pp.76-86, 2017-04-01 (Released:2017-04-29)

参考文献数

27

---

Fracture mapping conducted during gallery excavation on construction projects of a large-scale underground facility is based on traditional geological techniques such as visible observations and simple measurements of fracture orientation using a clinometer. Therefore, some difficulties persist, such as securing data quality and worker safety. Three-dimensional (3D) laser scanning, which can instantly acquire point clouds representing the 3D shape of an object surface, is can be effective for resolving these difficulties. In order to confirm the applicability of the three-dimensional laser scanning to the fracture mapping on a gallery wall, this study proposes the method for obtaining attribute information from a point cloud, such as trace length and orientation, associated with the spatial distribution of fractures. In the proposed method, the two-dimensional image is generated from the point cloud to obtain the trace map. After the proposed method was applied to an approximately 50-m-long horizontal gallery excavated into the granitic rock, the reproducibility of the attribute information of fractures obtained solely from the point cloud was examined. Results show that the number of fractures extracted from the point cloud is approximately 80% of those extracted by traditional geological techniques. Although the trace length reproducibility ratio of fractures is approximately 70%, fracture orientations calculated from the point cloud compare favorably with those measured by an on-site researcher. Most fractures that were not extracted from the point cloud do not act as water-conducting fractures because they had short lengths and because they were bonded tightly. Even if the fracture data obtained from the point cloud were applied to modelling for hydrogeological analysis, the results would probably not be influenced strongly. Results of this study indicate the possibility of applying 3D laser scanning to fracture mapping.

著者

平郡 伸一 庄司 浩史 西川 勲 小林 宙 井手上 敦

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.4, pp.68-75, 2017-04-01 (Released:2017-04-29)

参考文献数

19

---

Owing to the continual depletion of resources, low-grade nickel laterite ores are being treated nowadays to extract Ni. High-pressure acid leaching (HPAL) is a suitable process for treating nickel laterite ores. HPAL has the advantage of having a high extraction rate and low chemical consumption associated with the neutralization of iron; the low chemical consumption is owing to the formation of hematite precipitate in the residue. By studying the behavior of iron under pressure acid leaching, it was observed that sulfur and carbon contained in the ore decreased the redox potential and lead to Fe (II) dissolution. Iron concentration in the leached solution was decreased by oxygen rich leaching.

著者

米田 哲朗 前田 寛之

出版者

一般社団法人資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.124, no.12, pp.694-699, 2008-12-25 (Released:2011-02-15)

参考文献数

28

被引用文献数

1 4

---

Compositional and structural properties of clay minerals from hydrothermal systems show highly diverse and systematic variations related to their localities. The chemical compositions of chlorite, one of the most common clay minerals, are thought to have a close relationship with its formational environments such as geological conditions, temperature, chemistry of hydrothermal solution, etc. In this study two chlorite geothermometers were considered by using the chemical composition of chlorites from some hydrothermal ore deposits in Japan. The two chlorite geothermometers are the Cathelineau's thermometer giving an empirical temperature scale of chlorite formation in an active geothermal field, and the Walshe's thermometer giving a thermodynamic temperature scale based on exchange reactions of chlorite solid solutions. On the basis of a comparison of fluid inclusion geothermometry, it is concluded that the two geothermometers can be applied to different compositional types of hydrothermal chlorite. The Cathelineau's thermometer fits well for Mg-chlorite, and the Walshe's thermometer fits for Fe-chlorite, indicating that both two chlorite geothermometers can be used as exploration indicators for geothermal reservoirs and hydrothermal ore deposits. In addition, it must be emphasized that the impurities in the chlorite should be examined in applying the chlorite geothermometers to chlorites.

著者

中村 大 川口 貴之 渡邊 達也 川尻 峻三 山崎 新太郎 山下 聡

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.2, pp.4-11, 2017-02-01 (Released:2017-02-08)

参考文献数

12

---

Recently it has been found that frost heave phenomena can be seen not also in soil but also in rock. It is obvious, however, that the number of researches on frost heaving in rock is much less than that of researches on frost heaving in soil. In the present research, we newly developed test equipment in which a pressure transducer is incorporated into a device for testing frost heave in rock. Frost heaving tests were performed using three types of rocks (Ohya tuff, which is soft rock with high frost susceptibility; Kimachi sandstone, which is medium-hard rock with low frost susceptibility; and Sapporo soft rock, which is non-frost-heaving soft rock) to measure the suction pressure generated in the process of frost heaving. In these tests, we obtained fairly large negative pressures for Ohya tuff and Kimachi sandstone. In mediumhard Kimachi sandstone, negative pressure was generated before frost heaving displacement started. On the other hand, negative pressure was not generated in non-frost-heaving Sapporo soft rock. Therefore we considered that frost heaving in rock might be caused by negative pressure generated in the process of frost heaving.

著者

岸本 章宏 倉満 晶子 土橋 一輝 宇田 哲也

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.132, no.12, pp.199-206, 2016-12-01 (Released:2016-12-26)

参考文献数

33

被引用文献数

3

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A new smelting process of Ti via Bi–Ti liquid alloy is proposed, which comprises reduction of TiCl4 by Bi–Mg alloy, enrichment of Ti in Bi–Ti alloys, and vacuum distillation of the alloys. In this study, the continuous reduction of TiCl4 by Bi–Mg alloys and vessel materials for the reduction step were investigated. Firstly, we demonstrated the reduction of TiCl4 by Bi–Mg alloys and the subsequent recovery of Bi–Ti liquid alloys and MgCl2 repeatedly. As the result, the alloys containing 5.2–7.4 mol% of Ti were obtained. However, it was found that the reduction rate of TiCl4 by Bi–Mg alloys is much slower than that by pure Mg because of MgCl2 layer formed on the alloys, slow mass transfer of Mg in the alloy, and small activity of Mg. For fast reduction of TiCl4, it is required to inject TiCl4 into Bi–Mg alloys. Secondly, we kept Bi–10 mol% Ti alloys in stainless steel, soft steel, and Mo crucibles at high temperatures, and measured solubility of each metal in the alloys. The solubility of Mo in the alloy at 900℃ was 220 ppm, and elution from stainless steels and soft steel was dramatically suppressed at 500℃. However, it was found that most Mo in the alloy remains in Bi9Ti8 at the segregation cell. To decrease Mo content in Ti product, it is required that the vessel is cooled to lower temperatures than 900℃ or the shorter time of contact between Mo and liquid alloys is desired.