著者

坂田 章吉

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.138, no.7, pp.116-128, 2022-07-28 (Released:2022-07-28)

参考文献数

12

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The Federal Republic of Nigeria (herein after referred to as “Nigeria”) is the largest oil producing country in Africa and 13th in the world. However, community development is delayed especially in the Niger Delta where oil is produced. In this situation, many CSR community development projects of multi-national oil development companies (herein after referred to as “companies”) are implemented there.Frynas (2005) suggested that if the government’s community development (herein after referred to as “development”) is insufficient, people turn to companies for such development. It also suggested that, in general, CSR doesn’t succeed in its role, but if CSR were successful, this might ease the pressure on the government to undertake a development role.Sakata (2020) studied this by interviewing people in Nigeria, however, the sample size was not large enough and more study was required.In this study, Nigerian people in a sufficient sample size were interviewed to determine the ratio of people’s expectations of development by companies and government inside and outside of the Niger Delta, and the reasons for people’s expectations for each, in order to examine the factors of people’s high expectation for companies in the Niger Delta and occurrence of pressure reduction on the government.The study indicates that people’s expectation of development by companies is higher in the Niger Delta than in other areas, and that the most common reason for expectation of development by companies is “demand of compensation for using land and oil and causing environmental pollution in Nigeria by companies”, rather than “reliance on companies’ ability and resignation over the government’s inability to provide development”, which suggests that the factors of high expectation for the companies in the Niger Delta are the insufficient government’s development and the people’s idea that the companies should compensate to the communities and people who are suffered from the oil development in the Niger Delta. In addition, the study indicates that most people recognize that the government has a responsibility for development even though they expect development by companies, which suggests that the reduction in the pressure on the government is limited.

著者

亀山 正義 田原 康博 吉田 堯史 松浦 太一 宮吉 紗綾子

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.138, no.7, pp.103-115, 2022-07-28 (Released:2022-07-28)

参考文献数

19

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In some cases, mine drainage containing heavy metals (arsenic, cadmium, lead, and other metals) continues to flow out from mine mouths and accumulation sites in abandoned metal mines. The local governments that manage the abandoned mines continue to treat mine drainage water day and night. Therefore, practical and realistic measures to reduce the volume of mine drainage are required. A large amount of data on mine drainage has been accumulated for a long time at each mine. Also, several technologies have been introduced that make it possible to understand the actual hydrological water flow of mine drainage and to predict the quantitative effects of countermeasures. Under these circumstances, JOGMEC applied a surface water-groundwater coupled simulation technique to the old Matsuo Mine located in Hachimantai City, Iwate Prefecture. The simulation was used as a part of the results of the "Research and Study on Groundwater Control Technology" of the " Advanced Research and Study for Mine Drainage Treatment in Abandoned Mines Project", a project commissioned by the Ministry of Economy, Trade and Industry of Japan. It was confirmed that the existing countermeasures were efficient and effective under the limited budget. Thus, proving that it was the best practice.

著者

綱澤 有輝 古作 吉宏 坂入 義隆 塚田 浩二 斉藤 瑞稀 蛭子 陽介 三觜 幸平 陳 友晴 所 千晴

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.138, no.6, pp.95-102, 2022-06-30 (Released:2022-06-30)

参考文献数

14

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The high-pressure grinding roll (HPGR) has been known to achieve a high mineral liberation with relatively low energy consumption. However, quantitative methods for evaluating the effect of HPGR grinding on the promotion of the mineral liberation of copper ores have not been fully established. This study aims to establish a quantitative evaluation of promoting the liberation ratio of copper minerals by HPGR grinding. We performed clack observation using the combination of the paint penetration method and the mineral liberation analyzer (MLA). Direct clack observation reveals that HPGR grinding can promote the formation of cracks in the product particles. The liberation ratio of copper minerals is related to the percentage of cracks in the product particles. Besides, the grinding tests using a laboratory ultra-small scale showed that the liberation ratio of copper minerals became larger than that of the ball milling alone. In all conditions where HPGR grinding was conducted before ball milling, the ball milling time became almost half that of the ball milling alone. The grinding kinetic constant of the HPGR milling product in ball milling is also determined. The grinding kinetic constants for 80% passing particle size in HPGR grinding products are larger than that in feed ores, and they are consistent with the trend of ball milling time. This might be because the HPGR milling causes cracks in the particles, which are more easily ground in the subsequent ball milling. Consequently, this study demonstrates that the ratio of clacks and the grinding kinetic constant in the ball milling process after HPGR milling can be used as an index to quantitatively evaluate the effect of HPGR milling on promoting the liberation of copper minerals.

著者

木下 尚樹 安原 英明

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.138, no.6, pp.84-94, 2022-06-30 (Released:2022-06-30)

参考文献数

25

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The purpose of this study is to expand the application of wastepaper sludge ash (WPSA) as a construction material. The strength and thermal conductivity of WPSA solidified by hydration reaction were investigated for use as a ground improvement solidifier and civil engineering material. The mixture of fly ash, silica fume, gypsum, and ordinary Portland cement was also investigated. The effect of the mix proportion and the amount of the powder mixture on the strength was investigated, and the strength development was discussed based on the XRD and SEM-EDX results. The experimental results showed that the uniaxial compressive strength of mortar specimens with a water-powder ratio of 1.0 was 5 MPa to 9 MPa at 28 days of age. The strength of the mortar specimens decreased with the addition of fly ash but increased with the addition of by-products such as silica fume. The strength of the solidified material using WPSA was lower than that of the existing solidified materials. The strength of the solidified material made of WPSA was developed due to the formation of albite by hydration reaction, recrystallization of WPSA, and pozzolanic reaction with fly ash and silica fume. Then, the reflectance and thermal conductivity of the solidified material were measured, and the thermal conductivity was examined by the heat transfer experiments. The thermal diffusivity of the solidified material was also estimated by analyzing the experimental results. It was confirmed that the reflectance of WPSA was higher than that of ordinary Portland cement. In addition, the re-incineration of WPSA showed higher reflectivity. The thermal conductivity of the WPSA paste specimens was smaller than that of cement mortar and larger than that of gypsum. The results of the heat transfer experiments suggest that the thermal insulation property of the re-incinerated WPSA is improved.

著者

木下 尚樹 安原 英明 矢田部 龍一 加賀山 肇

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.138, no.6, pp.70-83, 2022-06-30 (Released:2022-06-30)

参考文献数

19

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It is obligatory to verify the performance of high-energy-absorbing pocket-type rockfall protection nets by full-scale experiments. While the performance verification by full-scale experiments can provide a practical evaluation, it requires a lot of cost and time because it is necessary to conduct the experiments under several conditions depending on the structure of the rockfall protection net. Therefore, the performance verification by combining full-scale experiments and numerical analysis may be a useful tool. In this study, a full-scale experiment of a high-energy-absorbing pocket-type rockfall protection net was conducted to evaluate the net performance with respect to the required capability, and reusability and repairability of the components by understanding the behavior of the net under the action of heavy weights. Throughout the experiment, the deformation of the net, the change of the wire rope tension with time, and the displacement of the top of the net and the top of the pillar were measured in detail. Moreover, it was confirmed that it is possible to evaluate the performance verification based on the performance requirements. Then, the full-scale experiment was replicated by numerical simulations to examine the effects of the rock shape on the behavior and performance of the simulated net. Through the thorough investigations on the deformation of the net, the relation between the maximum tension of the wire rope and the slip length of the shock absorber, the temporal change of the tension of each wire rope, and the absorbed energy of each structural member, it was judged that the reproducibility of the model predictions is adequately high. Specifically, when the impact energy is constant, the effect of the rock shape on the behavior and performance is considered to be small.

著者

狭川 義弘 山冨 二郎

出版者

The Mining and Materials Processing Institute of Japan

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.125, no.8, pp.409-419, 2009-08-25 (Released:2011-02-26)

参考文献数

42

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Block caving is a most cost effective underground mining method and it is expected as a major mining method in the near future by replacing large-scale/massive open pits where a risk of slope failure and waste/ore ratio is higher as pit depth is deeper. The Northparkes Mines is well known as a pioneer of block caving mining in Australia and has ever produced copper-gold ore by using block caving from 1995. The E48 mine is the fourth block caving project in the mines and its development was started in 2006 following the block cave production in the E26 mine. The ore body can be categorised as a porphyry copper-gold deposit and the geometry is almost shaped pipe. The extraction level is located about 600m below the surface and its footprint is sized only 310m x 193m in plan, which means the E48 has very 'tall' mining zone comparing to other block caving projects in the world. The cavability has been assessed by intensive geotechnical studies based on the past experiences in the E26 mine. The extraction level is designed to maximise not only mining recovery but also productivity, taking into account stability of all the drives. Post-undercut method was selected to initiate caving and designed carefully not to damage the extraction level excessively by stress concentration and blasting. In order to improve safety, work environment, productivity and mining cost, all underground electric loaders are unmanned and to be operated remotely from the surface office by only a couple of operators.

著者

渡邉 寛人 早田 二郎 浅野 聡 邑瀬 邦明

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.138, no.5, pp.51-59, 2022-05-31 (Released:2022-05-13)

参考文献数

18

被引用文献数

1

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Ion-exchange process with chelating resins was investigated for recovery scandium from sulfuric acid aqueous solutions. An iminodiacetic acid type chelating resin, Diaion CR11, had a higher Sc adsorption selectivity than other elements. Diaion CR11 had high trivalent ions adsorption, and almost divalent ions other than nickel were not adsorbed. The adsorbed metal ions were eluted with sulfuric acid, and scandium was separated from aluminum, nickel and chromium. Only iron (III) showed a behavior similar to scandium and was difficult to separate with Diaion CR11. The elution behavior was related to the stability constants of the complex of iminodiacetic acid and metal ions.

著者

清水 隆

出版者

The Mining and Materials Processing Institute of Japan

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.123, no.12, pp.614-619, 2007-12-25 (Released:2010-12-17)

被引用文献数

3 5

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The Mitsubishi Naoshima Smelter & Refinery started copper smelting operation in 1917, since then has been developed smelting and refining technologies like Mitsubishi Process, which is an efficient, pollution free continuous copper smelting and converting process. At present, Naoshima Smelter & Refinery has three major activities; copper business, precious metals business and recycling business. In this decade, Naoshima Smelter & Refinery has been utilized the copper smelting technology for recycling business, which consists of the treatment of the industrial wastes and the treatment of copper and/or precious metal-bearing materials. Two recycling plants were constructed as pre-treatment plants for Mitsubishi process. One is the incinerating and melting plant, and the other is washing treatment plant for fly ash from incinerators. The treated industrial waste from these recycling plants is fed to Mitsubishi Process to recover the valuable materials and hazardous heavy metals.

著者

奈良 禎太 加藤 昌治 佐藤 努 河野 勝宣 佐藤 稔紀

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.138, no.4, pp.44-50, 2022-04-28 (Released:2022-04-28)

参考文献数

34

被引用文献数

1

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It is important to understand the long-term migration of radionuclides when considering rock engineering projects such as the geological disposal of radioactive waste. The network of fractures and pores in a rock mass plays a major role in fluid migration as it provides a pathway for fluid flow. The geometry of a network can change due to fracture sealing by some fine-grained materials over long-term periods. Groundwater usually contains finegrained minerals such as clay minerals, and it is probable that the accumulation of such minerals occurs within a rock fracture upon groundwater flow, thereby decreasing the aperture of a fracture and the permeability. It is therefore essential to conduct permeability measurements using water that includes fine-grained minerals to understand the permeability characteristics of a rock; however, this has not been studied to date. In the present study, we use a macro-fractured granite sample to investigate the change of permeability that occurs under the flow of water that includes two different amounts of clay. Findings showed that clay accumulated in a fracture and that the permeability (hydraulic conductivity) of the granite sample decreased over time, which was greater in for the higher clay content. We concluded that the accumulation of clay minerals in the fracture decreased the permeability of the rock. Furthermore, we consider that the filling and closure of fractures in rock is possible under the flow of groundwater that includes clay minerals.

著者

荒牧 憲隆 村上 拓馬

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.138, no.4, pp.33-43, 2022-04-29 (Released:2022-04-28)

参考文献数

18

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We proposed a new gasification method to convert unused organic matter in sedimentary rocks to bio methane gas using microorganisms, known as Subsurface Cultivation and Gasification (SCG). Our approach uses hydrogen peroxide (H2O2) to decompose organic matter rapidly into usable substrates for methanogens. We previously reported that H2O2 would be useful for effective SCG at lignite, and conversion of organic matter from lignite into biogenic methane with the help of microorganisms is expected to be highly profitable. However, physical properties of the sedimentary rock are thought to change with the decomposition of sedimentary rock in the SCG method.A series of one-dimensional compression tests were performed for artificial coal seams prepared using the lignite sampled from Tempoku coalfield in the northern Hokkaido to investigate the stability of coal seam during an industrial production of substrates for methanogens in the subsurface environment. H2O2 was used in the one-dimensional compression tests to produce lower-molecular-weight organic components as a substrate of methanogen. Moreover, H2O2 solution was repeatedly injected into the artificial coal seam under compressive pressure. Oxidative decomposition of the artificial coal seam produced a high yield of low-molecular-weight organic acids. However, settlement of the artificial coal seam subjected constant loading was dependent on concentration and injection amount of H2O2.The biomethane deposits might become mechanically unstable during promoting decomposition of organic matter of coal seams, even if lignite has the greater resource potential for biomethane.

著者

松岡 秀和 三觜 幸平 河田 真伸 高谷 雄太郎 所 千晴

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.138, no.2, pp.12-18, 2022-02-28 (Released:2022-02-10)

参考文献数

31

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Copper sulfide minerals are the major raw materials for copper products. Copper sulfide minerals are mined at copper mines and concentrated by flotation process. In recent years, the mining of refractory copper ores, which is difficult to concentrate by flotation due to their fine grain size, presence of multiple copper mineral species, and fluctuation of the content ratio of these minerals in feed ore. In addition, the hydrophilization of copper mineral surfaces due to oxidation and the mineral content variation of ore result in poor and unpredictable performance of flotation operation. In this study, therefore, we focused on the activation of the copper mineral surfaces using sodium hydrosulfide (NaHS) to render the surfaces hydrophobic and tried to quantify the effect of the fluctuation of mineral content ratio by using a new flotation kinetic model. Two samples showing different content ratios of chalcocite, bornite, and chalcopyrite and having fully oxidized surface were used in the flotation tests. We established a new flotation kinetic model by considering the reaction between the copper mineral surface and NaHS and the depression of floatability by adsorption of hydrogen sulfide ions onto the copper mineral surface. As a result, a good relation was confirmed between the model and the flotation test results for both ore samples. This result showed that our model can accurately predict the flotation results of refractory copper ores and will encourage the further usage of these refractory copper ores in the future.

著者

岩崎 雄一 村田 道拓 川口 智哉 松本 親樹 保高 徹生

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.138, no.3, pp.28-32, 2022-03-31 (Released:2022-03-29)

参考文献数

26

被引用文献数

2

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For a total of 80 legacy mines in Japan, by assuming that untreated mine drainages were discharged and that metal loadings from sources other than mine drainage were negligibly small, we estimated seven element concentrations (Cd, Pb, As, Cu, Zn, Fe, and Mn) at water quality monitoring (WQM) river sites closest to individual mines (hereinafter referred to as the closest WQM sites) based on a simple dilution approach. In addition, for zinc as an example, the concentrations at the closest WQM sites were estimated by taking account into estimated zinc loadings from sources other than mine drainage. Results of the former analysis showed that the concentrations of all four elements (Cd, Pb, As, and Zn) at the closest WQM sites were predicted to be below Japanese environmental water quality standards in 50% of the legacy mines analyzed, which is not a small percentage. However, the result of the latter analysis showed that the contributions of treated mine drainages to the total loadings of zinc at the closest WQM sites were less than 50% in approximately 88% of the legacy mines analyzed. This result suggests that metal loadings from sources other than mine drainages at the closest WQM sites are not trivial in many legacy mines. Even if untreated mine drainages were discharged, estimated zinc concentrations in 72% of the WQM sites, where the annual average of measured concentrations of total zinc was below the environmental water quality standard (0.03 mg/L), were still below the standard. Despite a screening-level assessment based on multiple assumptions such as the simple dilution, results of the present study should be valuable for understanding the impact of discharging untreated mine drainages on metal concentrations in rivers receiving those from the legacy mines toward applying the water-quality management that secures the protection of downstream water use.

著者

髙谷 雄太郎 淵田 茂司 濱井 昂弥 堀内 健吾 正木 悠聖 所 千晴

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.138, no.2, pp.19-27, 2022-02-28 (Released:2022-02-26)

参考文献数

42

被引用文献数

3

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In decades, various studies on passive treatment methods of acid mine drainage (AMD) have been actively conducted in order to reduce the cost of AMD treatment. Open limestone channel is one of the most common methods and has already been implemented mainly in overseas. On the other hand, it is difficult to secure large channels in Japan due to its topography, we need to consider the use of alkaline materials with higher acid neutralization potential which enables successful treatment with narrower space. In this study, therefore, PAdeCS, a cement-derived environmental remediation agent, was used to remove the harmful metal elements by neutralization treatment. Then, we developed a simulation model assuming a combined system of open limestone channel and alkaline material (PAdeCS) channel and predicted the behavior of harmful metal elements within the combined channel. The simulation results showed that PAdeCS has extremely high acid neutralization potential, that high temperature is advantageous for neutralization treatment of harmful metal elements, and that the channel design needs to be changed depending on the initial drainage composition. Finally, a new flowchart for selecting the appropriate passive treatment method was proposed, which consists of three steps of the preferential removal of Fe, neutralization by limestone, and additional treatments.

著者

中野 博昭 大上 悟 西野 友朗 福島 久哲 小林 繁夫

出版者

The Mining and Materials Processing Institute of Japan

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.128, no.10_11, pp.590-595, 2012-09-25 (Released:2013-10-28)

参考文献数

15

被引用文献数

3 5

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Electrodeposition of Cu was conducted in a synthetic electrorefining solution to investigate the effect of gelatin, thiourea and chloride ions on the polarization curve for Cu deposition, morphology, texture, surface roughness and the throwing power of the deposited Cu. In a solution containing both gelatin and chloride ions, the cathode potential for Cu deposition was significantly polarized at current densities above 200A/m2, while the thiourea depolarized the potential for Cu deposition at 200 to 1000A/m2. In a solution containing the three additives, i.e. gelatin, thiourea and chloride ions, the potential for Cu deposition was polarized at 500A/m2. It is supposed that the synergistic effect of gelatin and chloride ions on the polarization prevailed over the depolarization effect of thiourea. In the Cu deposited at initial stage, the chloride ions promoted the field-oriented texture with the orientation of direction. However, Cu deposited at initial stage from the solution containing gelatin, thiourea and chloride ions was composed of both the inclined texture type and the epitaxial growth type of crystals. The surface roughness and throwing power of the deposited Cu was most improved in the solution containing gelatin, thiourea and chloride ions, showing the synergistic effect of three additives. The thiourea had an effect on decreasing the surface roughness of the deposited Cu, and chloride ions improved the throwing power of Cu.

著者

中尾 信典

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.138, no.1, pp.10-11, 2022-01-31 (Released:2022-01-28)

著者

佐藤 晃 森 拓実 中里 計麻

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.138, no.1, pp.1-9, 2022-01-31 (Released:2022-01-18)

参考文献数

16

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Limestone is one of the most important mineral resources, and it is only one mineral that can be fully supplied by domestic producers. Generally, a certain amount of ores is stored in the ore passes temporally after blasting excavation, and extraction is carried out from the bottom of the ore pass. However, the hang-up phenomena in the ore passes sometimes occurred and some cases are recently reported. Once the hang-up phenomena in the ore passes occur, it will cause serious problems. In this study, ore flow experiments in the vertical ore passes were conducted using ore pass models which was composed of transparent acrylic tubes, and the conditions of hang-ups were discussed. Since the ore passes were assembled with transparent tubes, it was also possible to observe the hang-up phenomenon directly. To discuss the effect of cross-sectional shapes of ore passes, two kinds of ore-passes, that is, circular and square shapes of cross-sections, are prepared. Using various sizes of ores, the relation between ore size and cross-sectional area was also discussed. It was found that the hang-up phenomenon almost did not occur when the ratio of ore pass size to the mean grain size of ores exceeds the value of 5. It was also found that the circular-shaped ore passes were a little preferable to avoid ore pass hang-ups compared with the square ore pass. The same procedure was applied to the mixed ores which two types of ores with different mean diameters are mixed. In this case, also, the results were almost the same as the results obtained by single-size ores. 3D-DEM analysis was also conducted, and the validity of the experiments was discussed.

著者

淵田 茂司 門倉 正和 所 千晴

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.137, no.12, pp.116-122, 2021-12-25 (Released:2021-12-25)

参考文献数

15

被引用文献数

2

---

Acid mine drainage (AMD) generation is a serious problem from the environmental and economic perspectives, because it contains a large amount of heavy metals and because there are high costs associated with maintaining the facilities, purchasing neutralizing agents, and disposing sludges; which are required for the treatment process. In this study, changes in AMD quantity and quality for the next decades were predicted by a three series tank model in three stages, by combining the first order kinetic calculation of sulfide minerals' dissolution for two metal mines (X and Y) in Japan. Results from the AMD quality model represented the decrease of heavy metal concentrations below the effluent standard values in 30–140 years, by considering dilution and/or additional dissolution by heavy rain and snow melting, although these predicted values diverged by our previous model. However, the low correlation coefficient values (0.23–0.63) observed between the measured values of heavy metal concentration and the values calculated by our new model, mean that other chemical reactions, such as sulfate and/or carbonate mineral dissolution could greatly affect the AMD quality. In fact, there was no correlation between the metal potential calculated by our model and the real distribution of sulfide minerals at X mine. Our results therefore indicate that specific geochemical reaction and geological information should be included in the AMD quality prediction model, to estimate more accurately the fluctuation of each heavy metal concentration during different seasons.

著者

葛巻 星 西岡 宣泰 藤代 史 武部 博倫

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.137, no.11, pp.110-115, 2021-11-30 (Released:2021-11-30)

参考文献数

27

被引用文献数

2

---

A stabilized zirconia oxygen probe was used to measure the oxygen partial pressure (OPP) at an electrode submerged in a copper slag melt at 1300 ℃. The OPP was controlled in the range of 10−10–10−5 atm owing to the presence or absence of a powdered carbon layer on the slag melt using a high-purity alumina crucible in argon (Ar) gas flow. Under suppression of magnetite formation at an OPP of approximately 10−10 atm, the viscosities of the copper slag and FeO-Fe2O3-SiO2-Al2O3 slag melts were measured between 1200 ℃ and 1300 ℃. The obtained values were in the range of 1.0×102–7.8×102 mPa・s. The dependences of total Fe/SiO2 mass ratio and Al2O3 concentration on viscosity were qualitatively interpreted from the aluminosilicate network structure viewpoint.

著者

宮本 真之 北田 敦 安達 謙 深見 一弘 邑瀬 邦明

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.137, no.11, pp.103-109, 2021-11-30 (Released:2021-11-30)

参考文献数

25

被引用文献数

2

---

CaCl2 is a low-toxic, inexpensive reagent that dissolves in large amounts in water to form highly concentrated aqueous solutions, or hydrate melts electrolyte. In this work, it was investigated that the concentrated CaCl2 aqueous solutions (aq) as novel lead (Pb) electrodeposition baths. While PbCl2 is poorly soluble in water at room temperature, PbCl2 dissolved up to 0.452 mol kg−1 ([Pb(II)] = 93.7 g kg−1) by the formation of PbCl42− complexes in the concentrated CaCl2 aq due to its high Cl− activity. Electrochemical measurements confirmed that the apparent exchange current density and the limiting current density of Pb electrodeposition decreased with increasing CaCl2 concentration. Since the diffusion of Pb(II) species was limited due to the high viscosity and ionic strength of the solution, agitation was effective in improving ion transport and electrodeposition rate. The presence of chloride ions in Pb electrolysis is usually detrimental due to the low solubility of PbCl2, however, the highly concentrated CaCl2 solution can be a potential candidate electrolyte for PbCl2-based electrolytic processes.

著者

山下 雄 高橋 純一

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.137, no.10, pp.98-102, 2021-10-29 (Released:2021-10-29)

参考文献数

10

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A pyrometallurgical process of metal recycling from waste lithium-ion batteries (LIB) has been developed. Basic process is that Co, Ni oxides which are from cathode materials of LIB and Cu which is from anode current collector are smelted and are reduced to metal, and the metal is refined in a next hydrometallurgical process. Since Al and Li contained in LIB are distributed to slag as oxides in the melting process, it is important to know the influence of these elements on the melting temperature of slag in determining the operating conditions. Therefore, the effects on the slag melting temperature when these elements and the amount of flux are changed are investigated and compared with the calculation results in FactSage (thermodynamic calculation software). In addition, based on the obtained melting temperature, waste LIB and flux were mixed and melted, and it was confirmed whether the metal and slag could be separated.