著者
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.136, no.1, pp.1-7, 2020-01-31 (Released:2020-01-31)
参考文献数
26
被引用文献数
2

Time dependence, probability distribution, and size effect have been investigated by many researchers and are still important issues in rock engineering. These seem to be different characteristics of rock but were found to be closely related to each other through laboratory tests with rock specimens in recent studies. In this paper, the theoretical aspects on the time dependence, probability distribution, and size effect of rock strength were explained, and some of the theoretical results were compared with the previous experimental results. The theoretical formulae based on the rate process theory that represent the failure progression of rock were introduced, and their relation to the theories of visco-elasticity and visco-plasticity was described. The exact solutions of the loading-rate dependence of strength and the creep lifetime were derived from the formulae and were compared with the experimental results of andesite. In addition, the exact solutions of the probability distribution of strength and creep lifetime and their relation to the statistics of extremes were described; the exact solutions of the size effect of strength and creep lifetime and their relation to the comminution theory were also described. The authors clarified what issues have been or have not been verified in previous studies and presented the subjects of future investigation.
著者
三宅 正男 石井 俊匡 山上 慶 平藤 哲司
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.135, no.12, pp.109-115, 2019-12-31 (Released:2019-12-26)
参考文献数
20

Leaching of copper anode slime using hydrochloric acid (HCl) and hydrogen peroxide (H2O2) is performed to recover Au. It is imperative to reduce the amount of the costly oxidizing agent, H2O2, used in this leaching. In conventional conditions, the Se contained in the slime is oxidized and dissolved by the leachant as well as Au. If Au alone can be selectively leached, it should reduce the use of H2O2. The calculation of equilibrium potentials showed that when the concentration of HCl is high, it is possible for Au to be selectively leached, while the dissolution of Se is suppressed. The selective leaching of Au was demonstrated by experiments using 8 mol L-1 and 12 mol L-1 HCl solutions with various amounts of added H2O2. In the selective leaching, the increase in the leaching rate of Au with increasing amounts of H2O2 diminished after the leaching rate reached 80%. This may be because Au remained inside the Se particles, and the contact between Au and the leachant was physically inhibited by the Se layer encompassing the Au atoms. However, a leaching rate of Au of greater than 95% was achieved, even when the leaching rate of Se was less than 30%. From these results, it was confirmed that the use of H2O2 can be reduced by the selective leaching of Au compared to the cases in which all Se in the slime is dissolved.
著者
中田 英喜 横島 美香 鈴木 祐麻 新苗 正和
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.135, no.11, pp.101-108, 2019-11-30 (Released:2019-11-28)
参考文献数
24
被引用文献数
3

The objective of this study was to deepen the understanding of the immobilization process of selenium (VI)contaminated soil when using immobilization agents consist of MgO and iron (II) compounds. The objective was achieved by introducing diffusion cells that allows us to physically separate soil and immobilization agent, and measuring the valence of selenium as well as the concentrations in liquid, soil, and immobilization agent phases. Experimental data showed that the addition of immobilization agents induced desorption of selenium (VI) from the contaminated soil, and the desorbed selenium (VI) was reduced into selenium (IV) by iron (II) compounds. The formed selenium (IV) was then effectively immobilized by re-sorbing on soil particles and immobilization agents. Also found was that more amount of selenium (IV) was sorbed on the immobilization agents as hydration reaction of immobilization agents proceeded. These insights obtained in this study are fundamental but important information to fully elucidate the selenium (VI) immobilization mechanisms that are required to improve the reliability of immobilization technology.
著者
高橋 良尭 山口 耕太郎 笹岡 孝司 濱中 晃弘 島田 英樹 一ノ瀬 政友 久保田 士郎 佐分利 禎
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.135, no.10, pp.94-100, 2019-10-31 (Released:2019-10-31)
参考文献数
19

Rock blasting is one of the most common techniques for rock breakage in the open-pit mining excavation. On the other hand, the application of the technique has been restricted by law since it may cause a serious impact on surrounding environment, such as flyrock, ground vibration and noise. According to the statistics, more than 70% of accidents relating to the usage of explosives is flyrock. This accident may cause serious damage to buildings, human beings, and objects in the surrounding area. However, a detailed guideline for prevention of flyrock has not been developed yet. From these points of views, a series of field experiments was conducted and initial velocity and flying direction of fragmented rock were discussed by considering blasting standard and rock mass conditions such as strength, fractures/cracks and joints. The result shows that powder factor and burden have strong influence on the initial velocity of fragmented rock. Not only blasting designs but also rock mass conditions, cracks/joints strongly effect on the initial velocity. In addition, it was also made clear that the existence of fractures/cracks/joints in the blasting face have an obvious impact on the direction of fragmented rock.
著者
夏井 俊悟 梨元 涼太 問谷 一偉 澤田 旺成 菊地 竜也 鈴木 亮輔
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.135, no.8, pp.71-82, 2019-08-31 (Released:2019-08-27)
参考文献数
72
被引用文献数
1

The transient behavior of the multi-interfacial flow can be modeled using recent Smoothed Particle Hydrodynamics (SPH) model. This developed numerical method is fully-Lagrangian particle-based approach, which can track the movement of many fluid phase directly. The advantage of this simulation model is a direct calculation in both of dispersed phase and continuous phase seamlessly. Thereby this model estimates transient behavior of interfacial behavior by predicting the changes of each interface shape. For example, numerical simulations have been performed for different conditions corresponding to different values of surface tension, viscosity and density, and the predicted topological changes as well as the theoretical interfacial shape of droplets can be validated. Based on this model, we carried out relatively large-scale interfacial flow simulations, investigated case studies of metallurgical processing, and evaluated the non-steady state flow of formed from various dispersed phase.
著者
中村 大 川口 貴之 千葉 貴久 伊藤 陽司 渡邊 達也 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.132, no.1, pp.14-21, 2016-01-01 (Released:2016-01-16)
参考文献数
5
被引用文献数
1

In this study, we conducted a follow-up survey of brick cracking on a brick wall in the parking space of JR Kitami Station and installed temperature sensors on the surface of the brick wall in order to measure changes in the brick wall temperature during late winter. In addition, we attempted to reproduce the brick cracking observed on the brick wall by conducting an indoor freeze-thaw experiment. The field investigation confirmed that the brick cracking on the brick wall occurred on the south-facing wall in the period from the coldest season to late winter. It was also confirmed from the records of the measured surface temperatures of the brick wall that, even in winter, the bricks could thaw in daytime and re-freeze at night, depending on the weather, solar radiation, and depth of snow coverage. Furthermore, we were successful in reproducing the brick cracking observed on the brick wall in the parking space of JR Kitami Station in the indoor freeze-thaw experiment. Our experience outlined above has demonstrated that frost damage can occur on the brick wall at JR Kitami station by a mechanism caused by the phenomenon of closed-system freeze-thaw, which the authors propose.
著者
林 良和 郭 柄霖 平島 剛 伊藤 竜也 中村 壮志 笹木 圭子
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.135, no.7, pp.63-70, 2019-07-31 (Released:2019-07-31)
参考文献数
23

Removal of borate in mine drainages by co-precipitation with hydroxyapatite (HAp) was developed from a laboratory scale to a pilot scale. Weakly acidic initial pH facilitated to enhance dissolution of Ca(OH)2 and decrease the dissolved carbonate concentration, leading to efficient immobilization of borate and arsenate. The NH4H2PO4 lowered best the equilibrium B concentration among different phosphate sources, avoiding the lattice strain of HAp. The added molar ratio of P/Ca significantly influenced the decreasing behavior of the B concentration, showing the optimal value of 0.3. In case of P/Ca larger than 0.30, the excess concentration of PO43- was probably adsorbed on Ca(OH)2 particles to prevent the dissolution, resulting in inhibiting the formation of HAp. In case of P/Ca smaller than 0.30, the production of HAp was limited, leading to less immobilized borate. All the optimized conditions as above were applied to the pilot scale with a 250 L reactor, where borate concentration was effectively reduced in also both batch and continuous tests.
著者
片岡 みなみ 尾原 祐三 Leona VAVRO Kamil SOUCEK Sang-Ho CHO Sang-Sun JEONG
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.135, no.5, pp.33-41, 2019-05-31 (Released:2019-05-25)
参考文献数
32
被引用文献数
5

岩石のモードI破壊靭性を評価するための試験法がこれまでに数多く提案されてきているが,同じ岩石の破壊靭性を異なった試験法で評価し,得られた結果が比較されることはまれである。このため,破壊靭性に及ぼす試験法の違いが明らかにされているとは言い難い。また,岩石の破壊靭性は試験法の違いだけでなく,用いる供試体寸法によっても影響を受けると考えられる。これらの影響を明らかにするために,様々な破壊靭性試験が行われてきた。しかし,これまでの実験では,同じ岩石で作製された供試体数が十分でなかったり,あるいは供試体寸法の違いの範囲が狭かったために,それらの影響を明らかにするまでに至っていないと考えられる。 本論文では,来待砂岩を供試体として用い,3種類の破壊靭性試験法,すなわち,CB試験,SCB試験およびSNDB試験を実施し,破壊靭性に及ぼす試験法の影響を検討するとともに,半径12.5mm〜150mmの範囲の供試体を用いたSCB試験を実施し,供試体寸法の影響を検討した。この結果,CB試験とSCB試験による破壊靭性はほぼ同等の結果を得ることができたが,SNDB試験の破壊靭性はそれらの値より小さく評価されることを示した。また,供試体寸法が大きくなるとともに破壊靭性も増大することを明らかにした。
著者
佐藤 康晴 清野 文雄 小笠原 啓一 山本 佳孝 佐藤 徹 平林 紳一郎 清水 賀之
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.129, no.4, pp.124-131, 2013-04-01 (Released:2014-04-14)
参考文献数
20
被引用文献数
5 9

The motion of a single MH-bubble in quiescent fluid was examined experimentally. If a methane-gas bubble is placed under the condition that hydrates nucleation can initiate, typically at high pressure and low temperature, a thin methane hydrate film is formed on the bubble surface and it alters the motion of the bubble in the fluid drastically. It behaves as if solid did.To clarify the fluid dynamics of MH-bubbles, we devised the special apparatus which enabled us to observe the three dimensional behaviours of the MH-bubbles under high pressure condition. The three dimensional motions of the MH-bubbles were captured by two high-speed cameras whose resolution was 1024*1024 pixel at 500Hz. To analyze the motions of the MH-bubbles, Direct Linear Transformation Method was adopted.Equivalent diameter of the MH-bubble was altered from 3.8 to 7.8 mm, which corresponded to the range from 555 to 1155 in Reynolds number, by replacing the nozzles with different diameters.The MH- bubbles in this range exhibited the zigzag motion, while methane bubbles the spiral motion. Main findings in this research are as follows:(1) The aspect ratio, the height to width ratio, decreased linearly with the increment of the equivalent diameter of a MH-bubble. This reflects the fact that the shape of the MH-bubble shifts from spherical to ellipsoidal. (2) Strouhal number which characterizes the zigzag motion of the MH-bubbles increased with Reynolds number. (3) The drag coefficients were measured up to the Reynolds number of about 1000. The drag coefficient of a MHbubble departs from the standard drag curve when the shape deformation become notable. After that, it rise in accordance with the progress of the deformation. These phenomena also have been observed in the behaviour of a bubble with a surfactant.
著者
武山 詳 坂口 清敏 渡邉 則昭 土屋 範芳
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.135, no.3, pp.25-30, 2019-03-31 (Released:2019-03-29)
参考文献数
26

Gypsum aggregate specimens have been used in the present study, because brittle, semi-brittle and ductile stress-strain behaviors of the specimen can be controlled only with confining stress level at the room temperature. At confining stresses up to 40 MPa, tri-axial compression and fluid flow experiments have been conducted on the intact specimens and single fracture specimens. It has been indicated that stress-strain behavior is independent of existence of fracture. Moreover, permeability of the single fracture specimen is much higher than intact specimen at conditions of brittle, semi-brittle, intermediate state between semi-brittle and ductile and ductile condition. On the other hand, permeability of the single fracture specimen is not so different from that of the intact specimen at conditions of a transitional behavior between semi-brittle and ductile stress-strain behaviors. As for the geothermal reservoir in the semi-brittle and ductile region, it was suggested that the fracture is retained and permeability is maintained when fracturing occurs due to hydraulic crushing or the like.
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.135, no.2, pp.15-24, 2019-02-28 (Released:2019-02-28)
参考文献数
16
被引用文献数
1

The rheological properties of cement slurries (including fresh concrete and high concentration paste for filling etc.) are complicated, therefore they are approximated by the Bingham plastic model. In recent years, the application of Herschel-Bulkley model is recommended for drilling mud. The rheological coefficients of these models are obtained by using measurement results of the rotational viscometer or experimental results of the flow in a circular pipe, and the pressure loss in pipe flows is obtained from these rheological coefficients. Therefor it is essential to properly select the model in order to design the slurry transportation. In the field of well drilling, the flow in a concentric annulus with a relatively large pipe diameter ratio is approximated by the flow in a parallelplate, so it is also necessary to consider the flow in a parallel-plate. In this study, first, a method to determine the rheological coefficients by the least squares method from measurement results of the rotational viscometer using the function provided in a spreadsheet is shown and a method to quantitatively select the rheological model using Akaike's information criterion is also shown. Next, after the exact solutions of flows in a circular pipe and in a parallel-plate is summarized, an approximate expression of wall shear stress is derived and the error analysis is performed, and its effectiveness is confirmed by using past experimental data. In addition, a method of calculating the rheological coefficients by the least squares method from measurement results of flows in a circular pipe and in a parallel-plate using spreadsheet is shown and this method is practiced by using the experimental data of the flow in pipes.
著者
大久保 敬祐 高橋 弘樹 田口 正美
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.135, no.2, pp.8-14, 2019-02-28 (Released:2019-02-21)
参考文献数
27
被引用文献数
1

Pushed by human activities, the atmospheric CO2 concentration has reached levels which have made extreme weather events more likely, and which threaten permanent climate changes for the world. In order to combat this, CO2 emissions must be reduced significantly. Electricity production and industry are two sectors which contribute greatly to the production of CO2, thus a reduction in the amount of CO2 produced by thermal power plants and factories could make a significant contribution to combatting climate change. The electrochemical reduction of CO2 in those sources is considered very likely to be a solution to the problem. In this study, the activity of a Pt oxide electrode in the electrochemical reduction of CO2 was investigated in a sulfuric acid solution. Pt oxide electrodes have shown superior activity for the methanol oxidation reaction, which is the reverse reaction of CO2 electrochemical reduction. Cyclic voltammetry of the Pt oxide electrode in a CO2-saturated H2SO4 solution showed a definite anodic peak at 0.6-0.8 V vs. SHE, which was not observed in an Ar-deaerated electrolyte. Thus, it was determined that the anodic peak could be related to the re-oxidation of the reduction product of CO2 during cathodic polarization. The activity of the Pt oxide electrode for CO2 reduction was much higher than that of the Pt electrode. It was concluded that the residual oxygen, which was hardly detected in the Pt electrode, improved the activity for CO2 electrochemical reduction on the Pt oxide electrode. Gas chromatography-mass spectrometry of the electrolytic solution after CO2 reduction revealed that the reduction product was mainly CH3OH. These results should be very useful for developing a new electrochemical reduction system for converting CO2 into CH3OH.
著者
藤原 達央 大川 浩一 加藤 貴宏 菅原 勝康
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.135, no.1, pp.1-7, 2019-01-31 (Released:2019-01-31)
参考文献数
33
被引用文献数
4

This study investigated an effective method to desorb CO2 from low-concentration (0.2 mol/L) monoethanolamine (MEA) solutions using calcium chloride (CaCl2) and ultrasound irradiation at 25 ºC. The pH value of the solution had a large influence on the desorption ratio of CO2 from MEA solution under ultrasound irradiation. CO2 was successfully desorbed up to pH8.2, and it was impossible to desorb CO2 at pH over 8.2. It was clarified that CO2 desorption by ultrasound irradiation is useful for the concentration of MEA solution of up to 2.0 mol/L, because the pH rises above 8.2 when the concentration of MEA solution is increased to above 2.0 mol/L. It also became evident that the addition of small amount of CaCl2 further increases the amount of CO2 desorbed during ultrasound irradiation.
著者
森田 進 大塚 武夫 前田 治
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.707-710, 2007-12-25 (Released:2010-12-17)
参考文献数
3
被引用文献数
1 1

Japan New Metals (JNM) was established in 1963, as a joint venture between Mitsubishi Materials and Awamura Mining, and has consistently produced tungsten, tungsten carbide and molybdenum powder from raw materials. Based on the nonferrous manufacturing technologies, we have produced high purity tungsten powder, heteropolyacids and several non-oxide ceramics powders. These are used for electronics devises, hard components and chemicals. In order to avoid the risk related to the supply of tungsten raw materials greatly dependent on China, JNM started a recycling business since 2002. Tungsten is recovered from cemented carbide scraps by the chemical process in the Akita plant.
著者
尾原 祐三 吉永 徹 濱地 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.134, no.12, pp.222-231, 2018-12-31 (Released:2018-12-27)
参考文献数
19
被引用文献数
4

This paper described the use of a drone in collecting data and analyzing images for monitoring of rock slope. The drone consists of four electric rotors and equips with 4K camera. Firstly, the fundamental experiments were performed by the developed monitoring system with the drone. A measurement accuracy was discussed for method of collecting and using image data. As the results, it is made clear for obtaining a high measurement accuracy that the distance between slope surface and drone is less than 20m for collecting data, and that the overlap of images is 80%, and that GPS data and coordinates of GCP (Ground Control Point) are used in analyzing images. After that, the system was applied to rock slope of an open pit mine and a quarry. The three dimensional model can be constructed with a high accuracy. Furthermore, the change of shape of rock slope can be estimated with the lapse of time. Basing on these results, it is concluded that the developed system is very effective for monitoring rock slope.
著者
成田 光好 大鹿 淳也 豊原 哲彦 岡本 信行 白山 義久
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.12, pp.634-638, 2015-12-01 (Released:2016-01-01)
参考文献数
9
被引用文献数
2

Japan Oil, Gas and Metals National Corporation (JOGMEC) conducted the Environmental Impact Study research from 2008 fiscal year under contract to the Ministry of Economy, Trade and Industry (METI) for the commercialization of Seafloor Massive Sulphide (SMS). It is necessary to consider the potential impacts of mining on the surrounding environment and to promote the project for long-term perspective. Particularly, because the specific chemosynthetic ecosystem and the unique biological communities exist around the hydrothermal area, the quantitatively evaluations of the environmental impacts and the conservation measures of biodiversity to avoid or reduce the effects on them as much as possible is required. The environmental assessment programs consist of baseline survey, environmental impact modeling, and the methodological concepts that will be applied to conserve biodiversity. In this paper, we will introduce the review of the project during 2008-2012 and the future prospects of EIA project for SMS mining.
著者
清水 賀之 畠山 信夫 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.134, no.10, pp.142-150, 2018-10-31 (Released:2018-10-26)
参考文献数
21
被引用文献数
5

A numerical analysis is conducted to examine an air-lift pumping system for mining rare-earth rich mud under 6000m deep seabed around the Minami-Tori-Shima. The numerical scheme in the analysis adopts the one-dimensional drift-flux model, which solves pressure and velocities as well as volumetric fractions of each phase in the air-slurry two-phase flow along a lifting pipe. The empirical formulas derived from experiments using rare-earth rich mud around the Minami-Tori-Shima estimate the pseudoplastic viscosity and the rheology constant as a function of volumetric concentration of mud in slurry. They are devised in the scheme to evaluate the pressure drop in air-slurry two-phase flow as the power-law fluid. Parametric studies were conducted to examine steady characteristics of the air-lift pumping system by changing the air flow rate, the water depth where the air was injected and back pressure. As a result, the basic characteristics of the air-lift pumping system were clarified. For example, with the air flow rate of 6kg/s, depth of water where air was injected of 3000m, back pressure of 0.2MPa (G), 6040m lifting pipe out of which 6000m is submerged, and 40m is above sea level, pipe diameter below the depth where the air was injected of 0.15m and above that depth 0.2m, it was found that the maximum mud flow rate was 1.01x103t/d, volumetric concentration of mud was 6.2%, slurry velocity was 3.8m/s, mixture velocity at the exit of the lifting pipe was 52m/s and power required was 2.0x103kW. In addition it was found that the performance of the system decreases when using the scheme as the power-law fluid compared with the one using the Mori-Ototake formula as Newtonian fluid. Furthermore, specifying back pressure is useful because of increased efficiency of the system, as well as for keeping the mixture velocity down at the exit of the lifting pipe.
著者
杉尾 学 豊田 典明 梶谷 啓介 大和谷 誠 中原 健一
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.130, no.10_11, pp.453-464, 2014-10-01 (Released:2015-10-02)

Sumitomo Osaka Cement Co., Ltd. (SOC) Kokura Mine and Mitsubishi Materials Corporation (MMC) Higashitani mine adjoiningly operate limestone mine at Hiraodai area in Kita-Kyusyu city, Fukuoka prefecture. MMC Higashitani mine need to replace underground facilities when bench down from current mining level in order to secure future minable deposit. SOC Kokura mine has undeveloped mining area between Higashitani mine, but cannot utilize their plenty minable deposit since there is no way to carry limestone to their cement plant because Kokura mine is located inland. In order to solve above issues, both mines started joint development project by focusing on the following five points. 1 Utilize the limestone deposit in SOC's undeveloped mining area and boundary area of both mines. 2 To plan production and shipping quantity for the purpose that all joint develop area can end mining at the same time. 3 Confirm content of installed facilities and investment cost between both companies and clarify way of cost allocation. 4 Ensure the safety operation and seek minimum cost. 5 Joint work to acquire necessary license/Approval and to solve social issue with local community. This joint project is not only aim to secure the limestone deposit, but also enable us to built long term supply system, obtain new customers and improve operating ratio by joint use of their facilities. And this approach would be the one of the ideal model of limestone mine.
著者
石川 明良 谷繁 岳志 田井 朝香 鈴木 祐麻 新苗 正和
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.134, no.9, pp.131-136, 2018-09-30 (Released:2018-09-27)
参考文献数
13
被引用文献数
4

Chloride is one of the effective medium in which platinum group metals (PGMs) can be brought into a solution, thus chlorocomplexes are particularly important in the process chemistry of PGMs separations. Rh (III) chlorocomplexes are poorly extracted into organic solvents, which is due to the charge of the complex as well as those inert character in a solution, that is, formation of RhCl6-n(H2O)n(3-n) - (n=1-6) . The problem of solvent extraction of Rh from chloride solutions has not yet been solved and there is no effective industrial extractant for Rh. PGMs are traditionally separated from one another and the other metals by a complex series of selective precipitation techniques. These are generally inefficient in terms of the degree of separation achieved. Solvent extraction applied to refining process for PGMs offers several advantages over the traditional precipitation methods. Adding Sn (II) to a Rh (III) feed is a good procedure which can be used to make Rh react more easily to extraction, however, stripping of Rh from the loaded organic pahse is very difficult. In the present study, the extraction of Rh from hydrochloric acid solutions with tri-n-octylamine (TOA) and tri-octyl methyl ammonium chloride (TOMAC) were tested to clarify the effect of addition of Sn (II) on the extraction of Rh and stripping of Rh.