資源と素材
Online ISSN : 1880-6244
Print ISSN : 0916-1740
ISSN-L : 0916-1740
114 巻, 7 号
選択された号の論文の9件中1~9を表示しています
  • 石川 峯生
    1998 年 114 巻 7 号 p. 447-454
    発行日: 1998/06/25
    公開日: 1999/10/01
    ジャーナル フリー
    Since 1973, Saganoseki Smelter & Refinery had operated two flash smelting furnaces together to produce 330,000 mtpy of copper. However, in 1990's, economical situation required the smelter more increased productivity to remain competitive. The program to integrate two flash furnaces into one was carried out maintaining the same production. Modifications were done on the pneumatic concentrate drying system, concentrate feeding system, concentrate burner and furnace cooling system, etc. to double the furnace throughput. A new large cryogenic oxygen plant was constructed replacing two old plants. Single flash smelting furnace operation has started in March 1996. As a result, much improvement of productivity and cost reduction were accomplished. This paper describes about details of modifications and operational results.
  • 安田 清隆
    1998 年 114 巻 7 号 p. 455-459
    発行日: 1998/06/25
    公開日: 1999/10/01
    ジャーナル フリー
    Major activities in the direction of developing a commercial nickel-metal hydride rechargeable batteries occurred in the middle 1980s and some Japanese companies started to commercialize these batteries for small computer and electronic appliances in the early 1990s. For most of batteries, MmNi5 (Mm = misch metal) based alloys are exclusively utilized. As metal hydride electrodes could ideally replace the cadmium electrode of nickel-cadmium battery and had much higher electrode capacities, these batteries were easily accepted in commercial. After that, annual production of hydrogen-absorbing alloys has risen drastically. Main research and development for hydrogen-absorbing alloys used in commercial nickel-metal hydride batteries is now directed toward lower price and higher capacity. MmNi5-based alloys are still under development to improve their electrode performances and to reduce the cost of raw materials. Other hydrogen absorbing alloys with higher capacities such as Zr-Mn-Ni, Ti-V-Ni and Mg-Ni systems are also under investigation at both the fundamental and applied levels.
  • Budi SULISTIANTO, 城戸 利夫, 水田 義明
    1998 年 114 巻 7 号 p. 461-466
    発行日: 1998/06/25
    公開日: 1999/10/01
    ジャーナル フリー
    The combination between numerical methods and field measurements have been used by many researchers to analyze rock engineering problems. In numerical analyses, the far field stress state should be postulated at the beginning. As the results, however, it happens that generally the calculated stress does not match correctly with the measured stress. The fault can be addressed to the postulated far field stress state, since the high confidence of in-situ measurement technique has been used. In order to eliminate this difference, a kind of back analysis has been developed by the authors to determine the far field stress state using 3D FSM (3 Dimensional Fictitious Stress Method). The model of topography and the real field case were used to confirm the applicability of the calculation procedure. From this study, it is shown that the method is convenient to determine correctly the far field stress state, if the topography perturbation of the stress state at an arbitrary point A can be modelized using FSM, and if each component of the far field stress state is defined as a linear function of depth.
  • 大賀 光太郎, 平松 章男, 清野 克也, 樋口 澄志, 太田 真治
    1998 年 114 巻 7 号 p. 467-473
    発行日: 1998/06/25
    公開日: 1999/10/01
    ジャーナル フリー
    In order to reduce the methane emission from mining panels into the working area, an effective methane drainage from the coal seam at the high concentrations of methane is needed. One of the methods is to control the pressure at the optimum level in methane drainage pipeline network. We developed a program for calculation of methane gas flow in methane drainage pipelines of an underground coal mine to control the flow rate of gas and concentration of methane in the network. Some cases were calculated by using methane drainage pipelines networks of Taiheiyo Coal Mine. From the results, there is no difference between the calculated results using the developed calculation program and measured results, practically. We believe that using this calculation program leads to good results when they change a part of the methane drainage pipeline network and control the flow rate in the network.
  • 八田 夏夫, 面高 正明, 高津 隆浩, 藤本 仁, 宅田 裕彦, 姜 重錫
    1998 年 114 巻 7 号 p. 475-482
    発行日: 1998/06/25
    公開日: 1999/10/01
    ジャーナル フリー
    This paper is concerned with a numerical model for the steady-state flow characteristics of the gas-liquid two-phase mixture flowing upward in a vertical pipeline with an abrupt enlargement in cross sectional area. The system of governing equations used is based upon the multifluid model and the transitions of gas flow pattern are taken into consideration in the system of governing equations. For the case of an abrupt enlargement in diameter in a coaxial pipeline, the procedure of the numerical calculation to obtain the flow characteristics in the pipeline section after a sudden change in diameter has been proposed in the present investigation. At the same time, the experiments have also been performed using two kinds of lifting pipes in order to confirm the validity of the present numerical model. As a result of the comparison of the calculated results with the experimental data, we have confirmed the applicability of the system of governing equations as well as the validity of the procedure of the numerical calculation proposed here to the prediction of the flow characteristics of the gas-liquid two-phase mixture in a vertical pipe with a sudden change in diameter.
  • 山口 雅嗣, 野中 道郎
    1998 年 114 巻 7 号 p. 483-490
    発行日: 1998/06/25
    公開日: 1999/10/01
    ジャーナル フリー
    River, lake and reservoir environments have been drastically deteriorated along with the economical and industrial developments of the country. The change of the human life style is also another important factor affecting on the pollution of water environments. One of the most effective and economical ways to conserve, improve and purify the water environment should be the enhancement of the dissolved oxygen concentration by aeration. An enhanced aeration system is developed to cope with low efficiency, scale-up difficulty and restricted versatility accompanied with conventional aeration systems. The developed aeration system utilises the centrifugal shear stress to generate an enormous number of fine air bubbles and to establish the high propagation performance of mixing energy. The pressure loss of the cyclone-like aerator is deduced from the dimensional analysis and experimental works, which serves to scale up the aeration system and to evaluate the energy consumption of the whole system. The performance of the aeration system is experimentally evaluated in terms of the maximum aeration rate and the dissolved oxygen transfer rate. The former is confirmed to take a remarkably higher value and the latter is expected to be much faster than those in conventional aeration systems.
  • 石田 秀輝
    1998 年 114 巻 7 号 p. 491-496
    発行日: 1998/06/25
    公開日: 1999/10/01
    ジャーナル フリー
    The global environment is now exerting great influence on our life. It is not an overstatement to say that there would be no meaning in developing new materials unless due consideration is given to the load they exert on the global environment. We have been studying a new manufacturing system which is based on both mankind and earth in the coming unavoidable recirculation based society. One of the solutions is to develop the closed manufacturing system which creates the material where input (fossil energy and natural materials) and output (exhaust gases and waste materials) will be reduced to their utmost limits. In this report, as one of the examples of developing the material considered for both mankind and earth, details of the development and its actual results on the application of hydrothermally solidified soil (Earth Ceramics) to a house floor are discussed. This was developed from the research on the closed manufacturing system. Originally, soil has high abilities such as controlling humidity, preserving heat and so on. It is possible to solidify soil by adding slight amount of Ca(OH)2, mixing, forming and then processing under saturated steam pressure at lower than 200 °C where the original ability of soil is maintained. The solidified material has similar strength to that of ordinary cement and its energy consumption for solidification is almost 1/5 to 1/7 of ceramic manufacturing in general. This solidified material has high humidity controlling ability and relatively high heat capacity and it is possible to control a room climate in a sophisticated way without using fossil energy. After one year application to a house, it was clarified that the application of Earth Ceramics can reduce energy in everyday life almost by 25 %.
  • 池田 攻
    1998 年 114 巻 7 号 p. 497-500
    発行日: 1998/06/25
    公開日: 1999/10/01
    ジャーナル フリー
    The geopolymer binder technique for monolithic materials production was briefly outlined. Monoliths can easily be prepared from mineral powders by mixing them with sodium silicate solutions at ambient temperature. Following 3 sources are necessary for preparation: geopolymer liquor, inactive filler and active filler. The first is sodium silicate solution working as binders. The second is ordinary mineral powders such as quartz, kaolin, pyrophyllite as well as waste powders such as fly ash, red mud and other type of slimes. The last is water quenched granulated blast furnace slag acting as a solidification agent and usually blended so as to be consisting of 10 ∼ 30 percent of total solid powders. Ratio of geopolymer liquor to solid powders were ranging from 0.45 to 0.80 depending on filler characters. Slurries cast into molds solidify in 1 ∼ 3 h to overnight due to slow polycondensation of geopolymer liquor subsequently occurring at ambient temperature. Generally over 4 MPa in flexural strength and over 10 MPa in compressive strength were reached at 28 d age and especially kaolin and pyrophyllite fillers showed extremely high strength, up to 19 MPa for flexural strength and up to 75 MPa for compressive strength. Furthermore, blending these minerals to waste powders such as fly ash was attempted to improve the weak monolith strength and it was found that pyrophyllite is the most effective mineral for such objectives
  • 吉留 久夫, 春田 一吉
    1998 年 114 巻 7 号 p. 501-507
    発行日: 1998/06/25
    公開日: 1999/10/01
    ジャーナル フリー
    Offensive odor as well as noise is now an important environment problem to take countermeasures for preservation of environment. In 1988 NICHIBOH Co., Ltd., developed "Biosoil Deodorizing equipment" which utilizes microorganism in deodorizing. This equipment has been effectively used in deodorizing at sewage disposal plants. This system is improved on the defects of traditional soil deodorizing equipment and is free from maintenance in many years. In the field of air pollution purifying, microbiological technology is used only for deodorizing. A benefit of microorganism deodorizing equipment is lower maintenance costs comparing to the other methods such as activated charcoal adsorption and chemical treatment which have the same level of deodorizing performance, and it has no secondary pollution. In order to realize the system, it is important to set conditions for microorganism and to decide which odor components (which type of industry) we apply. In this paper, the odor regulation standards and deodorizing technology, and characteristics of Biosoil Deodorizing equipment and examples of its actual operation are reported.
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