Hokkaido Polytechnic College

Hokkaido, Japan

Hokkaido Polytechnic College

Hokkaido, Japan
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Van Long T.,Tohoku University | Van Long T.,Pohang University of Science and Technology | Palacios J.,Centro Regional Of Investigacion Para El Desarrollo Sustentable Of Atacama | Sanches M.,University of Concepción | And 5 more authors.
ISIJ International | Year: 2012

Slags as the by-product of copper making have been produced in large amounts in Chile, and about 5 million tons of slags are estimated to be disposed every year and about 50 million tons have been already accumulated near the mine site. Typical Chilean copper slag contains about 0.3 mass% Mo which is the same to the grade of primary mine production of molybdenite and the copper slags also contain about 40 mass% of Fe and 1 mass% Cu. Recovery of Mo from Chilean copper slags is quite attractive to secure a stable Mo supply. The feasibility of the recovery of Mo from copper slags as Fe-Mo alloys by carbothermic reduction is investigated in the present study. Mo in the copper slag is found to be fully recovered as Fe rich Fe-Mo alloy. The recovered alloy contains about 0.60 mass% Mo and 2.4 mass% Cu. To use the recovered Fe-Mo alloy effectively in the special steel industry, which is the most important market for molybdenum, Cu in the produced Fe-Mo alloy is successfully decreased from 2.4 mass% to 0.1 mass% by using FeS-Na 2S flux. Thus, Mo recovery from Chilean copper slag can be promising. © 2012 ISIJ.


PubMed | Saitama Prefectural Showa Water Filtration Plant, Japan National Institute of Materials Science, Yokohama Harbor Polytechnic College, Tohoku University and 2 more.
Type: | Journal: Scientific reports | Year: 2016

The lifetimes of ionic vacancies created in ferricyanide-ferrocyanide redox reaction have been first measured by means of cyclotron magnetohydrodynamic electrode, which is composed of coaxial cylinders partly exposed as electrodes and placed vertically in an electrolytic solution under a vertical magnetic field, so that induced Lorentz force makes ionic vacancies circulate together with the solution along the circumferences. At low magnetic fields, due to low velocities, ionic vacancies once created become extinct on the way of returning, whereas at high magnetic fields, in enhanced velocities, they can come back to their initial birthplaces. Detecting the difference between these two states, we can measure the lifetime of ionic vacancy. As a result, the lifetimes of ionic vacancies created in the oxidation and reduction are the same, and the intrinsic lifetime is 1.25 s, and the formation time of nanobubble from the collision of ionic vacancies is 6.5 ms.


Matinde E.,Metals | Sasaki Y.,Pohang University of Science and Technology | Hino M.,Hokkaido Polytechnic College
ISIJ International | Year: 2012

Effects of pre-melting operation on the vaporization behavior of phosphorus from standard and Fe 2O 3-added incinerator ash of sewage sludge were investigated. The sewage sludge ash samples were prepared by pre-melting at 1723 K in LaCrO 3-heated electric furnace for 3 h using alumina crucibles and argon gas flow rate of 100 m1/min. The vaporization behavior of phosphorus gas species from pre-melted incinerator ash of sewage sludge samples was compared with that from the as-received samples. Results show that the P2 and P4 gas species vaporized more easily from pre-melted standard Sample B than from pre-melted Fe 2O 3-added Sample A. The pre-melting operation stabilized the phosphorus compounds in the solid state reduction process and had a strong effect on the vaporization behavior of molecular phosphorus gas species at higher temperatures.


Matinde E.,Tohoku University | Hino M.,Tohoku University | Hino M.,Hokkaido Polytechnic College
ISIJ International | Year: 2011

This paper proposes a novel process for the pre-treatment of high phosphorus iron ore by pre-reduction, air jet milling and screening methods. The dephosphorization behavior was evaluated as a function of such parameters as the milling gas kinetic energy, E k and specific energy consumption, E sp. At a fixed milling gas kinetic energy, the dephosphorization treatment behavior was highly dependent on the solids feed rate and the degree of sintering of the pre-reduced phases. The proposed pre-treatment process involves a pre-reduction process by carbonaceous materials at 1200°C, and air jet milling using E k of 325.24 kJ and E sp of 3.24 kJkg -1h followed by fine screen separation using a 25 μm screen size. © 2011 ISIJ.


Seok S.-H.,RIST | Seok S.-H.,Tohoku University | Miki T.,Tohoku University | Hino M.,Tohoku University | Hino M.,Hokkaido Polytechnic College
ISIJ International | Year: 2011

The Ti deoxidation equilibrium of Fe-Ni, Fe-Cr and Fe-Cr-Ni alloys saturated with 'Ti3O5' and Ti2O3 phase was clarified in previous researches. Solubility of Fe, Cr and/or Ni oxides in 'Ti3O5' phase equilibrated with liquid Fe-Ni, Fe-Cr and Fe-Cr-Ni alloys at 1823 K to 1923 K were measured by SEM-EDS. It was confirmed that the solubility of Fe, Cr and/or Ni oxide in 'Ti3O 5' phase at low Ti content increase with decrease of Ti content in alloys. Titanium content that dissolution of Fe, Cr and/or Ni oxide into 'Ti3O5' phase becomes apparent increases with increase of Cr and/or Ni content of the alloys. The activity of Ti deoxidation product, 'Ti3O5' phase, equilibrated with Fe-Ni, Fe-Cr and Fe-Cr-Ni alloys was also evaluated by Redlich-Kister type polynomial. Equilibrium between Ti and O at low Ti content of those alloys was analyzed using the activity of 'Ti3O5' phase. © 2011 ISIJ.


Takase Y.,TOBISHIMA Corporation | Wada T.,Hokkaido Polytechnic College | Ikeda T.,TOBISHIMA Corporation | Shinohara Y.,Tokyo Institute of Technology
Journal of Structural and Construction Engineering | Year: 2012

Recently, it has become increasingly important to instigate more widespread seismic retrofitting for seismically weak structures in Japan, which is frequently subject to massive earthquakes. Generally, post-installed anchors are used to connect the seismicretro fitting members to existing members. However, no computational models of post-installed anchors have yet been proposed in previous studies to evaluate stress-displacement relationships. Accordingly, we developed a new mechanical model for post-installed anchors. In this model, the kinking behavior of anchor bolts, bearing behavior of concrete, and tensile behavior of anchor bolts are considered. The proposed model can reasonably simulate the mechanical behaviors of the previous test results.


Kumadaki M.,Muroran Institute of Technology | Yoshino M.,Hokkaido Polytechnic College | Sato K.,Muroran Institute of Technology | Itoh H.,Muroran Institute of Technology
IEEJ Transactions on Fundamentals and Materials | Year: 2014

We deposited SiCN thin films by RF plasma CVD (Chemical Vapor Deposition) method using a mixture of Tetramethylsilane (TMS), nitrogen, and hydrogen gas. Deposited films were measured some properties with Fourier-Transform Infrared Spectroscopy (FT-IR), X-ray Photoelectron Spectroscopy (XPS), Ellipsometry and Atomic Force Microscope (AFM). We found that the temperature of substrate increased elimination and absorption reaction on the surface, and a fine film could be deposited at the temperature of 973K. To deposit SiCN with lower temperature, we changed H2 flow rate. As results, we found that H2 flow rate had great influence on the efficiency of decomposition of TMS. Moreover, the roughness of substrate was affected by the mixture rate of TMS. We could obtain the films nearly similar to the 973K ones at the state of 100Pa of pressure, 773K of substrate temperature, 80sccm of H2 flow rate, and TMS mixture rate of 3% to 5%. In particular, 5% of TMS mixture rate could be considered as the best condition on this experiment. © 2014 The Institute of Electrical Engineers of Japan.


Inao T.,Muroran Institute of Technology | Kumadaki M.,Muroran Institute of Technology | Satoh K.,Muroran Institute of Technology | Yoshino M.,Hokkaido Polytechnic College | Itoh H.,Muroran Institute of Technology
IEEJ Transactions on Fundamentals and Materials | Year: 2014

Recently, as a great demand for high-strength and high-hardness materials is rising, improvement in performance of tools which manufacture those materials is being needed. Generally, tools to manufacture such materials are given high-hardness coating. Diamond and DLC (diamond like carbon) film are regarded as typical high-hardness materials, though, they can't be given to iron tools because carbons contained in them have high reactivity to iron. Consequently, the boron-nitride film which doesn't contain any carbons is expected as a coating material which can be adapted to iron tools. In this research, we prepared boron-nitride thin films on Si substrate using RF plasma CVD (chemical vapor deposition) method apparatus with a gas mixture of argon, nitrogen and trimethylborate (TMB: B(OCH3)3). © 2014 The Institute of Electrical Engineers of Japan.


Kusama Y.,University of Tokyo | Ishidoya Y.,Institute of Indoor Climate | Miura M.,Hokkaido Polytechnic College | Miyazaki T.,Hokkaido Polytechnic College
Journal of Environmental Engineering (Japan) | Year: 2016

The objective of this study is to report the passive thermal storage effects when applying PCM plastered wall on the surface of a wall. First, the measurement method of the basic thermal performance test of thermal storage building materials was examined. The examination revealed that the material required to be heated at a rate of 20 [min. /K], and for more than 10 [K] width except in the phase change region at the thermo-hygrostat. Second, the heat balance of the window was measured in the experimental module. The heat balance of the integrated value during the measurement period was +16.2 [MJ/m2]. By measuring the natural room temperature, it was found that PCM plastered wall demonstrated indoor environmental improvements. Finally the heat flow of the PCM layer was measured, and the thermal performance of PCM plastered wall was verified. It was revealed that after applying the PCM plastered wall, the energy savings were estimated at 17% for this module in Otaru, Hokkaido, which is a snowy cold region in Japan.


Takase Y.,Chiba Institute of Technology | Wada T.,Hokkaido Polytechnic College | Ikeda T.,Chiba Institute of Technology | Shinohara Y.,Tokyo Institute of Technology
Proceedings of the 8th International Conference on Fracture Mechanics of Concrete and Concrete Structures, FraMCoS 2013 | Year: 2013

Recently, it has become increasingly important to instigate more widespread seismic retroftting for seismically weak structures in Japan, which is frequently subject to massive earthquakes. Generally, post-installed anchors are used to connect the seismic retroftting members to existing members. However, no computational models of post-installed anchors have yet been proposed in previous studies to evaluate stress-displacement relationships. Accordingly, we developed a new mechanical model for post-installed anchors. In this model, the kinking behavior of anchor bolts, bearing behavior of concrete, and tensile behavior of anchor bolts are considered. The proposed model can reasonably simulate the mechanical behaviors of the previous test results.

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