資源と素材
Online ISSN : 1880-6244
Print ISSN : 0916-1740
ISSN-L : 0916-1740
112 巻, 10 号
選択された号の論文の13件中1~13を表示しています
  • 秩父地区残壁研究会
    1996 年 112 巻 10 号 p. 665-669
    発行日: 1996/09/25
    公開日: 2011/01/27
    ジャーナル フリー
    In Japan, some of limestone quarries have difficulties in development of new areas due to environmental restrictions. Cooperative development and operations at Mt. Bukoh are one of the development examples which meet environmental requirements and natural resource conservation.
    Mt. Bukoh of which original elevation was 1336m S.L. is located in the western part of Saitama pref. In the early days of development, each company commenced quarrying halfway up the mountain and ended up with only a small amount of mineable reserve. In order to fully exploit the whole resource and to maintain the final slope stability, it was required for the three companies to commence quarrying from top of the mountain maintaining the same operation level together with the same slope design and reforestation plan of the final slope.
    Owing to the geological structure, it is inevitable that a large final slope which is 2 to 3 km wide and 700 to 800m high-will be formed as quarrying progresses. Therefore it is vital for the three companies to secure slope stability for a long time in harmony with environment protection. All the data acquired through the series of surveys and studies were put into the computer and a comprehensive analysis was implemented. And a automatic survey system which monitors movement of the final slope started for measurement of distances from the station of a surveyor to various survey points on the slope.
  • 伊藤 右橘
    1996 年 112 巻 10 号 p. 670-674
    発行日: 1996/09/25
    公開日: 2011/01/27
    ジャーナル フリー
    Recovery of such valuable metals as zinc, lead and iron from steelmaking dust is, in other words, treatment of industrial wastes. The basic requirement in its implementaion is, therefore, not to generate another type of wastes from this operation.
    1. Using the St. Joe process, Toho Zinc Co., Ltd. had established the technology to recover zinc, in the from of zinc oxide, contained in leaching residues generated from electrolytic zinc refining. In this process, zinc is vaporized in the strong reduction atmosphere in the vertical electro-thermic furnace. The remarkable feature of this technology is that most of iron content in the clinker, which is generated from the process as final waste, is metallic and thus can be recycled as iron raw meterial.
    2. In the meantime, to manufacture chemical grade zinc oxide from steelmaking dust, it was necessary to combine the St. Joe process with an additional technology aimed to remove impurities.
    3. Theory of selective choridizing vaporization during the roasting process had been established as such additional technology, however, this theory had never been applied to manufacturing in any industrial scale. To implement the theory in the industrial scale, we conducted a fundamental test using a boat as well as two feasibility tests using rotary kilns with the dimensions of 0.43m.I.D.×10.8mL and 1.8m.I.D.×25mL, respectively. As a result of a series of tests, we concluded that the technolgy of selective chrolidizing roasting of lead, cadmium, etc. is feasible, and implemented the commercial production.
    4. Favorable results are being obtained in the oxidzing atmosphere at the temperature of 1100-1150°C in the rotary kiln with the dimension of 2.5m.I.D.×38mL. More than 95% of lead is vaporized and quality of zinc oxide produced is found satisfactorily stable.
    5. The chemical grade zinc oxide plant was installed in 1974 in the Onahama factory to treat steelmaking dust. The plant is currently treating approximately 50, 000-60, 000 tons of dust annually to produce 16, 000 tons of chemical grade zinc oxide per year.
    6. The above achievement is the result of renovation in our technology and rationalization at our plant over the past 22 years. We are committed to continuing steady efforts to make further progress in such areas as recovery and utilization of heat energy, the rate of recovery of valuable metals, and quality of the product.
  • 岩崎 巌
    1996 年 112 巻 10 号 p. 675-681
    発行日: 1996/09/25
    公開日: 2011/01/27
    ジャーナル フリー
  • 正路 徹也, 小林 祥一, 孟 憲国, 金田 博彰
    1996 年 112 巻 10 号 p. 683-687
    発行日: 1996/09/25
    公開日: 2011/01/27
    ジャーナル フリー
    The availability of GPS (Global Positioning System) has been examined in three areas. The first is a fixed point on the roof of a building of the University of Tokyo. The second area is around the Hishikari gold mine, southwestern Japan. The area was selected because topographic maps (1/25, 000) are published. The topography consists of gentle hills. The third area is Yunnan Province, southwestern China, where foreigners are prohibited to use topographic maps. The surveyed area is mostly mountainous. Measured values at the fixed point are scattered within 100m from the true position. The average point is located 30m south from the true position. In the Hishikari area, each GPS value is compared with the coordinates given by a topographic map. The deviation between the GPS value and the coordinates is within 300m. The reason why the deviation is larger than the error at the fixed point is that the coordinates given by a map includes error. In Yunnan, the accuracy was checked by the reproducibility. At many sites, satellites were not found because of steep slopes and high trees. A relatively wide space was located, however, within 300m from each site. When 4 satellites were found in wide areas, values were scattered in a circle with a diameter of 200m. When 4 satellites were found in narrow areas, the diameter was 500m. When only 3 satellites were found, the diameter was 1, 000m. These values are larger than the error of the pacing (less than 10 m for 100m distance). The result suggests that the GPS can provide location data with the accuracy enough to geoscience discussions in regional scales.
  • 坑底情報解析技術に関する研究 (第3報)
    唐澤 廣和, 大野 哲二, 小杉 昌幸
    1996 年 112 巻 10 号 p. 688-694
    発行日: 1996/09/25
    公開日: 2011/01/27
    ジャーナル フリー
    The main objectives of this report are to confirm the applicability of the methods for the estimation of rock strength and tooth wear to insert bits. These methods were obtained from the test results of the milled tooth bits with different tooth wear as described in the 2nd report. Therefore, drilling tests were conducted using 101.6mm-dia insert bits with different tooth wear. The main results obtained from the tests are as follows: 1. The relation between the effective axial energy per revolution divided by bit diameter (Feu/Nd) and the effective rotary energy per revolution divided by cross-sectional area of bit squared ((8Te/d2)2), is the information which shows the rock strength independent of tooth wear. The drilling strength of rock (Ds) can be obtained from the relation between them.
    2. The relations between Ds and the penetration strength of rock (Is), Ds and the specific energy calculated from the effective rotary energy (Se), Ds and the threshold weight per unit length of bit diameter (Fc/d), are effective information to estimate the tooth wear quantitatively.
    From these results, it became clear that the methods for the estimation of rock strength and tooth wear obtained from the milled tooth bits are applicable to the insert bits.
  • 岩盤開発設計のための予測とモニタリング (その8)
    水田 義明, 岡崎 幸司, 永田 邦博
    1996 年 112 巻 10 号 p. 695-699
    発行日: 1996/09/25
    公開日: 2011/01/27
    ジャーナル フリー
    Especially for open pit mining, one can not always develop every ore deposit distributed on the surface and so, one usually tries to excavate down to greater depth in order to get larger volume of the material from the deposit which is already begun to develop. Since slope stability decreases with increase of height of the rock slope, it is important to know how to excavate in order to stabilize the rock slope and how deep one can mine down.
    As the properties of the rocks of which the slope consists can not completely be determined from observation of a section of the slope because those are greatly different if the positions are different. It suggests that prediction of stabilility of rock slope is difficult in comparison with case of soil slope.
    However, recent rapid progress in higher performance and larger capacity of computer enables to deal with the problems which are complicated to some degree, that is, it is possible to do approximate prediction for a problem through numerical simulation by putting some assumed conditions into calculation and it is mostly effective measure.
    The authors carried out three dimensional elastic analysis by the boundary element system developed by them, in which soft layer is modeled as the joint elements, making an existent limestone quarry an object of study. They carried out numerical simulation of behavior of rock slope and showed the predicted results on the stability of the slope currently remained and on the stability decreases for the cases that rock slope becomes higher with progress of mining in future.
  • 砂岩の変形・強度特性と組織に関する基礎的研究 (第3報)
    萩野 克彦, 中村 章, 石島 洋二
    1996 年 112 巻 10 号 p. 701-706
    発行日: 1996/09/25
    公開日: 2011/01/27
    ジャーナル フリー
    The rate of Maximum Stress Drop (RMSD), which is drived from the complete stress-strain curve and indicates the severity of unstable brittle fracture, is function of confining pressure. It becomes maximum when the confining pressure corresponds to about half the overburden pressure. RMSD also depends on the fracturing mode, being relatively larger when it is of single-shear type, which is the dominant mode when the rock fabric shows anisotropy.
    Based on a model study to simulate the post-failure behavior, an index named “brittleness” was derived which is defined as the ratio of the stored strain energy to the one required to create the fracture surfaces. It is shown that the relationship between brittleness and confining pressure is similar to the one between RMSD and confining pressure, implying that brittleness is an index to effectively measure the severity of unstable fracturing. Also, the magnitude of the brittleness is larger when simple shear-type is assumed as the fracturing mode. Finally, the prediction of the magnitude of the confining pressure at the point of brittleductile transition coincided with the measured one.
    Concerning to the effects of geological processes on the mechanical properties, the following was noted. Firstly, the magnitude of the confining pressure at the brittle-ductile transition point is approximately equal to the overburden pressure corresponding to maximum depth of burial. Secondly, the value of the confining pressure, which corresponds to the bending point of the peak strength criterion, correlates with the overburden pressure at the site where the samples were collected from.
  • 竹原 孝, 菅原 勝彦
    1996 年 112 巻 10 号 p. 707-713
    発行日: 1996/09/25
    公開日: 2011/01/27
    ジャーナル フリー
    The abrasive jet, which is one of the water jet technology, is widely used in the industry for materials cutting and drilling. Since the abrasive jet is formed by mixing solid particles with a high velocity water jet, erosive effect of the abrasive jet is higher than that of conventional water jet. However, few basic studies, such as flow characteristics of abrasive jet, similarity low of fluid mechanics and so on, have been carried on.
    In this paper, experimental study is performed by the abrasive jet with silica sand particles to investigate flow characteristics and erosive action of the abrasive jet. The time-averaged velocity of the abrasive jet in the experiment is 70m/sec to 250m/sec, determined by means of the impact force measurement.
    The theory is proposed to estimate the energy loss and the velocity of abrasive jet, the momentum and the kinetic energy of abrasive, in terms of abrasive mixing rate. Moreover, the distance attenuation of the velocity of the abrasive jet is clarified by means of the impact force measurement, then the dispersion of the abrasive jet is discussed comparing the erosion shape of targets. Analyzing the relation between the velocity of the abrasive jet and erosion speed of the target is analyzed, it is concluded that the erosion speed is proportional to the kinetic energy for ductile materials such as metals, and proportional to the momentum for brittle materials such as fine ceramics.
  • き裂網モデルによる石炭のガス透過性の研究 (第1報)
    今井 忠男, 中島 巌, 朝倉 國臣, 後藤 龍彦
    1996 年 112 巻 10 号 p. 714-718
    発行日: 1996/09/25
    公開日: 2011/01/27
    ジャーナル フリー
    The purpose of the present study is to prove the mechanism of gas permeability of coal by effect of stress. Practically, Crack network model was supposed for the pore structure in coal. Gas permeability of coal was investigated by calculating the flow admittance which was simulated by the crack networks.
    As the results of these simulations, a linear relationship was found between a number of crack per unit area and a flow admittance in the case of the crack network made by Monte Carlo method. This result correspond to effect of a failure fracture on gas permeability of coal. Moreover, a exponential relationship was found between a number of block crack for a grid network and a flow admittance in the case of the crack network made by percolation process. This result correspond to effect of compression on gas permeability of coal.
  • Ezequiel Cruz SANCHEZ, 杉山 和正, 齋藤 文良
    1996 年 112 巻 10 号 p. 719-722
    発行日: 1996/09/25
    公開日: 2011/01/27
    ジャーナル フリー
    メカノケミカル的に活性化したタルクから, 0.5mol/dm3硫酸あるいは0.5mol/dm3塩酸を用いて, 298Kと333Kの温度下でマグネシウム抽出実験を行った。遊星ミルによるタルクの30分乾式粉砕では, タルクの結晶構造はほぼ無定形な状態へと変化する。この変化は, タルクの結晶構造におけるマグネシウム環境構造の変化を表し, したがって, 酸浸出過程では, マグネシウムが選択的に抽出されることを示唆する。硫酸並びに塩酸を用いた抽出実験では, 抽出時間は30分で十分であり, 未粉砕産物からのマグネシウム抽出は, ほとんどなく, 粉砕時間30分では約40%まで増大する。3時間粉砕処理した試料を常温で上記濃度の硫酸と塩酸により浸出すると, マグネシウム抽出率は, それぞれ約70%, 約63%となる。それでもシリコンの抽出は依然として3%以下に抑制される。
  • 銅製錬自溶炉のシャフト内の反応解析 (第3報)
    森 芳秋, 家守 伸正
    1996 年 112 巻 10 号 p. 723-728
    発行日: 1996/09/25
    公開日: 2011/01/27
    ジャーナル フリー
    A two-particle reaction model proposed by one of the authors was discussed on the basis of available information and then used to simulate oxygen pressure profiles along the reaction shaft. In the simulation an equilibrium state between reacted particles and gas phase was assumed. Oxygen pressure profiles obtained by equilibrium calculations were compared with those measured in a commercial furnace.
    The following results were obtained.
    1. The two-particle model can explain quantitatively the decreasing profiles of oxygen pressure along the reaction shaft.
    2 The calculated results show that the oxygen pressure of the molten particles flying downwards in the shaft approaches quickly to the oxygen pressure of the slag stored in the settler when the unreacted particle ratio decreases rapidly in the upper zone of the shaft. As predicted by the two particle model, a concentrate burner showing such a tendency in the oxygen pressure profile was found to have good operating results in terms of dust generation.
    3. In designing a concentrate burner, it is indispensable to take mutual reaction of the particles in the shaft into consideration.
  • 大上 悟, 秋山 徹也, 福島 久哲, 後藤 靖人, 友清 芳二
    1996 年 112 巻 10 号 p. 729-734
    発行日: 1996/09/25
    公開日: 2011/01/27
    ジャーナル フリー
    The morphology and the structure of the Al-Mn alloys electrodeposited from the molten A1Cl3-NaCl-KCl-MnCl2 salts were investigated using scanning electron microscope, X-ray diffraction.
    The alloys became lustrous with an increase in Mn content. X-ray diffraction patterns of these alloys showed that the alloys of lower Mn content consisted of α-Al crystalline phase. With an increase in Mn content, the intensities of the diffraction peaks from the crystalline phase decreased, while a broad peak appeared.
    Further, the microstructures of electrodeposited Al-Mn alloys of various Mn content were observed by transmission electron microscope. The electron diffraction pattern of ca. 7 mass % Mn alloy showed α-Al polycrystalline phase. With an increasing Mn content in deposit, the alloy phases changed from a-Al to amorphous phases. These phases showed lamellar structure which was parallel to the substrate.
    In electron diffraction images of Al-Mn alloy of ca. 30 mass % Mn, four broad rings were observed and they werereflected from microcrystalline intermetallic compound Al6Mn with the grain size of 3 to 5nm.
  • 福井 康隆, 福田 洋一, 猿木 友理恵, 加藤 悦朗
    1996 年 112 巻 10 号 p. 735-737
    発行日: 1996/09/25
    公開日: 2011/01/27
    ジャーナル フリー
    In the preparation of Ag Pd powders by coprecipitation from a reducing solution, the addition of ammonium acetate as a buffer in a reacting solution using ammonium formate and hydrazine as a reducing agent gave powders which can be changed to alloy at lower temperature. In this paper, the study of the relation between homogeneity of Ag/Pd composite powders and temperature changing to alloy is reported.
    Under the reacting condition, by addition of ammonium acetate in reacting solution, using ammonium formate and hydrazine as a reducing agent, the contact of Ag and Pd is close. As a result, homogeneous Ag/Pd composite powders produced were changed to alloy easily by the heat treatment.
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