Shigen-to-Sozai
Online ISSN : 1880-6244
Print ISSN : 0916-1740
ISSN-L : 0916-1740
Volume 108, Issue 8
Displaying 1-8 of 8 articles from this issue
  • Hideo HIRAYAMA
    1992 Volume 108 Issue 8 Pages 567-573
    Published: August 25, 1992
    Released on J-STAGE: January 27, 2011
    JOURNAL FREE ACCESS
    Saganoseki Smelter & Refinery, one of the largest smelters in the world, had its annual copper smelting capacity of 300, 000 metric tons in 1983. Thereafter, it had been operated at low production rate because of the economic deterioration for 6 years.
    During these years, technological and operational improvement, progress of facilities maintenance, and Mdevelopment of advanced operation control system have been carried out under the firm belief that the storm could be weathered. First of all, the principal concept for reforming the Smelter was established and all of effort were concentrated in this direction. Process technology developments were attained in all of unit processes, such as the prevention of dust accretion at flash furnace boiler, and the prolongation of anode mould life.
    As a result, much improvement in smelting cost reduction and productivity has been accomplished. Moreover, copper smelting capacity was reinforced to 330, 000 tonnes per annum without the increase of the number of main smelting facilities.
    The concept for smelter innovation, the summary of process technology progress, and the general idea of computer integrated manufacturing system are presented in this paper.
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  • Zenji HORII
    1992 Volume 108 Issue 8 Pages 575-578
    Published: August 25, 1992
    Released on J-STAGE: January 27, 2011
    JOURNAL FREE ACCESS
    This is to describe a Large Offroad Dump Truck Unmanned Navigation System used in Torigatayama Limestone Quarry.
    The system has been developed with cooperation of Nittetsu Mining Co., Ltd. and Shin Caterpillar Mitsubishi Ltd. and equipped on CAT 777B (85 tons payload). The system has been in production use.
    The Unmanned Truck enables high speed travelling under severe climatic conditions.
    The Unmanned Dump Truck Navigation System has following features.
    1) The system is an Autonomous Guidance System and does not need large ground facilities such as guiding lines.
    2) The system is of all weather type and can be used day and night under severe climatic conditions in quarries.
    3) The system is composed of multiple fail-safe constructions.
    4) The system is fleet system that controls a set of trucks as a fleet.
    5) The system has a learning function of a loading position.
    6) The system has maximum ground speed of 30 km/hr in forward and 10km/hr in reverse, which enables high speed travelling.
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  • Sukeyuki MORI, Tsuyoshi HARA, Goichi TSUJI
    1992 Volume 108 Issue 8 Pages 579-583
    Published: August 25, 1992
    Released on J-STAGE: January 27, 2011
    JOURNAL FREE ACCESS
    In Japan, limestone is one of the self-sufficient mineral resources, but is used mostly as a raw material for cement production. Other more valuable use for this resource must be found. We thought pulverization of limestone was the most important subject, so we pulverized it by the Tower Mill (Type KD-1) in dry semi-continuous systems, and examined factors affecting the weights or the particle diameters of the pulverized products. In every experiment, we made the weight of steel balls in the pulverizer and the number of revolutions of the screw constant, and varied the weights of limestone and the air flow rates (Um) in the tower. We found that decreasing the value of Um decreased the weight and the particle diameter of the pulverized product. We also found that the maximum value of the particle diameter (Dmax) of the pulverized product was dependent on the value of Um. We obtained the minimum value of Dmax, 16μm, when the weight of limestone was 1.0kg and the value of Um was 0.10m/s.
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  • Keiichiro TANIGUCHI, Harushige KUSUMI, Katsumi TERAOKA, Takao OHASHI
    1992 Volume 108 Issue 8 Pages 585-592
    Published: August 25, 1992
    Released on J-STAGE: January 27, 2011
    JOURNAL FREE ACCESS
    In the determination of the shear strength of rocks, a lot of similar specimens are needed to obtain satisfactory results, but the preparation of the specimens of same characters involves great difficulties, especially in the case of discontinuous rocks. It is desirable if the strength envelopes could be obtained from only one specimen.
    In this study, we carried out two types of CFS tests, and a series of constant stress shear tests for plaster specimens with regular triangular joint. In addition to these tests, we carried out multi-stage shear tests for rock specimens with artificially generated irregular joint. We made comparison of the results obtained by these tests, and examined the applicability of CFS tests.
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  • Study based on large-scaled models
    Takahiro SUGIURA, Yoji ISHIJIMA, Gota DEGUCHI
    1992 Volume 108 Issue 8 Pages 593-600
    Published: August 25, 1992
    Released on J-STAGE: January 27, 2011
    JOURNAL FREE ACCESS
    Large-scaled model experiments have been conducted to study the strata behaviors accompanying longwall mining in a flat coal seam at a great depth, leading to the following results: With the face approaching, the abutment pressure appeared which was recognized by the increase of the in-situ stress, P-wave velocity and amplitude. With the face passing, the roof failure occurred which was characterized by the rapid decrease of P-wave velocity and amplitude. And then they were regained in the closed goaf. When the bonding strength between the seams was relatively large, roof caving hardly occurred in the goaf. It resulted in the maximum abutment stress of about five times the virgin stress. But, when the bonding strength was small, the bed seperation and the roof caving easily occurred with the face advancing, and the corresponding abutment stress was restricted twice the virgin stress.
    In the field observations on stress changes and caving at Yotsuyama pit of Miike Colliery, the phenomena which are similar to those of the models were gained.
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  • Seisuke OKUBO
    1992 Volume 108 Issue 8 Pages 601-606
    Published: August 25, 1992
    Released on J-STAGE: January 27, 2011
    JOURNAL FREE ACCESS
    Some constitutive equations focusing on time-dependent behaviour of rock have been proposed by early workers. However, most of them can be applied to restricted loading condition, that is, a constitutive equation can be applied to only creep or only constant strain rate test. Moreover, few of them can be solved analytically. This is one of the reasons why the relation of time-dependent behaviour or rheological phenomena between different loading conditions still remains open to discussion.
    In this study, a very simple constitutive equation of variable compliance type is discussed, which has been proposed by the author. The constitutive equation can be solved analytically for several loading conditions such as creep, relaxation, constant strain rate, constant stress rate and allows to examine the relations of time-dependent behaviour among these loading conditions.
    It is well known that strength increase with loading rate in constant strain rate. Also, it is known that life time in creep decreases with increase of creep stress. By means of analytical solution of the proposed constitutive equation, it is shown that these two phenomena are closely related and life time in creep can be estimated by the result of constant strain rate test. Also, strength obtained by constant strain rate test and constant stress rate, life time of creep test and relaxation test, relation between creep strain and width of stress-strain curve, etc are discussed.
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  • Recovery of functional double oxides from their slicing dusts by flotation method
    Feng GU, Isao MATSUOKA
    1992 Volume 108 Issue 8 Pages 607-610
    Published: August 25, 1992
    Released on J-STAGE: January 27, 2011
    JOURNAL FREE ACCESS
    In order to recover functional double oxides, such as gadolinium gallium garnet (GGG) from its slicing dust by flotation method, the depression of green carborundum (GC) which is an abrasive has been investigated by using various organic colloids.
    Corn starch was the most effective depressant for GC. The adsorption of corn starch on GC surface was low in the alkaline pH range and increased as pH decreased. It is considered that the adsorption of corn starch on GC surface through hydrogen bonding between hydrogen atoms in corn starch molecule and oxygen atoms on GC surface becomes favorable as pH decreases, because the electrostatic repulsion between corn starch and GC decreases owing to the decrease of negative charge on GC surface. On the other hand, the adsorption of corn starch on GGG surface was high in the alkaline pH range and low in the acidic pH range. The decrease in the adsorption of corn starch on GGG in the acidic pH range may be explained by the reason that hydrogen ions are strongly adsorbed on the oxygen sites on GGG surface so that corn starch can not be adsorbed. Also, the adsorption of corn starch in the acidic pH range was further decreased by the specific adsorption of sulfate ions. Accordingly, corn starch may be adsorbed on GC surface in preference to GGG surface in the acidic pH range, particularly, when sulfuric acid is used as a pH regulator.
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  • Feng GU, Isao MATSUOKA
    1992 Volume 108 Issue 8 Pages 611-615
    Published: August 25, 1992
    Released on J-STAGE: January 27, 2011
    JOURNAL FREE ACCESS
    In order to recover lithium niobate (LN) from slicing dust, flotation separation of YAG from green carborundum (GC) has been investigated by using dodecylammonium acetate (DAA) as a collector.
    The zeta potential of LN was negative at pH above 2.8 in the presence of potassium nitrate. The floatability of LN with DAA was high in the weakly acidic to the alkaline pH range and decreased remarkably with decreasing pH in the pH range less than 4. The floatability of LN could not be activated with multivalent anions, such as sulfate ions, but it was activated by fluoride ions, resulting in high flotation recovery in the acidic pH range. The activation with fluoride ions may be caused not only by the increase in negative charge on LN surface (enhancement of electrostatic adsorption of DAA), but also by the chemical interaction between fluoride ions adsorbed specifically and DAA. LN was selectively floated from GC by using corn starch as a depressant in the presence of fluoride ions at pH 2 to 4.
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