Journal of the Mining Institute of Japan
Online ISSN : 2185-6729
Print ISSN : 0369-4194
ISSN-L : 0369-4194
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Volume 66, Issue 744
Displaying 1-4 of 4 articles from this issue
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  • Studies on Bog-iron-ores (Report 2)
    On the hydrated structure of Bog-iron-ore
    Masao MUKAI
    1950 Volume 66 Issue 744 Pages 202-207
    Published: May 25, 1950
    Released on J-STAGE: July 13, 2011
    DOIhttps://doi.org/10.11508/shigentosozai1885.66.202
    JOURNAL FREE ACCESS
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    The crystal form of Bog-iron-ore has been considered, in the previous report of our studies, as a Goethite ferm with lower degree of crystallization. In the present report, its hydrated structure is discussed from the dehydration curves of thermobalance-and differential-thermo-analyses, and from dehydration-and moisture-reabsorbtion-tests. Main results obtained are as follows:
    1. The adhesive A-vdier of Bog-iron-ore may be devided into three types: moisture, absorbed water, and binding water. Nearly equal amounts of water are found in each type of hydration.
    2 When Bog-iron-ore is heated slowly, the moisture is lost under 100°Cand the absorbed wa-ter is lost gradually over the range between 100°C and about 220°C.The binding water is lost suddenly at about 220°C.
    3. The binding water which has been considered to be combined in the crystal lattice of Goethite, is suposed to be a sort of absorbed water finely dispersed in crevices of crystallite of Goethite. Therefore, it can be said that the lattice in its crystallite of Goethite has a definite type of crystal form other than that of hematite and has the special structure in its secondery crystal form.
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  • On the Phenomenon of the Air Ejection in the Deep Well-Sinking by Air Jet
    Goro OMORI
    1950 Volume 66 Issue 744 Pages 208-216
    Published: May 25, 1950
    Released on J-STAGE: July 13, 2011
    DOIhttps://doi.org/10.11508/shigentosozai1885.66.208
    JOURNAL FREE ACCESS
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    To succeed in the deep well-sinking method in shaft-opening, it is very important that let the skinfriction due to the earth pressure on the periphery of the well be as small as possible, that is, let reduction efficiency for the skin friction by the air which is ejected in the ground and ascends allong the Qutside wall of the well be max. For this purpose, position, distance, number of the air pocket, and pressure, capacity, of the air reservoir must be decided rationally. This paper give the solution for the most important problem which is to be base in those rational decision. That ist (1) the relation between the pressure, the velocity, of the air which ejects from the orifices in the airpockets and the external pressure on the periphery of the well sunk in the ground, (2) the relation between the pressure of the air pressure and the time accompaning to thus ejection.
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  • Scientific Control of Mill Operations
    Hidehiko MINO
    1950 Volume 66 Issue 744 Pages 217-231
    Published: May 25, 1950
    Released on J-STAGE: July 13, 2011
    DOIhttps://doi.org/10.11508/shigentosozai1885.66.217
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  • [title in Japanese]
    1950 Volume 66 Issue 744 Pages 232-235
    Published: May 25, 1950
    Released on J-STAGE: July 13, 2011
    DOIhttps://doi.org/10.11508/shigentosozai1885.66.232
    JOURNAL FREE ACCESS
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