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Volume 65, Issue 739
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Nobuo Fusamura1949 Volume 65 Issue 739 Pages 381-384
Published: December 25, 1949
Released on J-STAGE: July 13, 2011
JOURNAL FREE ACCESSThe term “ Amount of produced coal dust” in coal mining has been carelessly used without any definite idea when the amount of suspending or settling coal dust in coal mine was measured. By generalizing some experiments and calculations, we devise some formulas to be enough to presume the true amount of produced coal dust accompaning with coal mining in the long wall working face. With this method we can easily calculate the total amount of coal dust during a con, tant time, and then the 'amount of coal dust per one ton of coal mining. This figure gives an important idea for the prevention of coal dust explosion in coal mine.
Some of the important formulas for the calculation of true produced coal dust are as follows:-Wt=α· WL· L/1-e-α L α=4.6/L log10 (WL/WL/2-1) where Wt=Total amount of produced coal dust during t hours.
WL, WL/2=Total amount of suspending coal dust passed at the end and the middle of a long wall working face during t hours.
L=Length of the working face.
α=Coefficient of dust settling per unit distance.
Supposing the amount of coal exploited during this t hours is C tons, the amount of produced coal dust per one ton of coal mining, K, is given by the next formulas. K=WL· L/C·α/1-e-α LView full abstractDownload PDF (830K) -
Onzo Jyo1949 Volume 65 Issue 739 Pages 385-391
Published: December 25, 1949
Released on J-STAGE: July 13, 2011
JOURNAL FREE ACCESS1. The ζ potentials of coal particles and air bubbles in the ageous f;o1utions of tarioits electrolytes were studied.
2. The flotation test of coal was carried out to know the effect of ζ potential on the recovery of coal.
3. In the flotation of coal, ζ potential have the serious effect on the recovery of coal.View full abstractDownload PDF (1741K) -
Metallurgy, Part I. Equilibrium of the Reaction 1/2 S2+2C02=2C0+S02Yoshiyuki Umetsu1949 Volume 65 Issue 739 Pages 392-398
Published: December 25, 1949
Released on J-STAGE: July 13, 2011
JOURNAL FREE ACCESSThe reduction eguilibrium of solid cuprous sulphide by carbon dioxide has been studied by means of the kinetic method at various temperatures ranging from 700°C to 1050°C, and the following relation between the common logarithm of equilibrium constant K and absolute temperature T was obtained.Cu2S (s) +2CO2=2Cu (s) +2CO+SO2 logK=-17, 401/T+6.226
By the result above described and some known thermodynamical data, the following relation between the equilibrium constant, K of the gas reaction 1/2S2+2C02=2CO+SO2 and absolute temperature T was calculated. logK=-10, 941/T+4.805View full abstractDownload PDF (1172K) -
Takuzo Shimzu1949 Volume 65 Issue 739 Pages 399-402
Published: December 25, 1949
Released on J-STAGE: July 13, 2011
JOURNAL FREE ACCESSIn roasting Kuromono with NaCl, Zinc ferrite is not produced at 400 to 700°C. When the mixture of Kuromono, CaCO3 and NaCl is roasted and leached with dil. HCl, the % extraction of Zn does not vary with the roasting temperature, but that of Fe is minimum, and that of Cu is maximum at 550°C. When the mixture of Kuromono, Ca (OH) 2 and NaCI is roasted and leached, the % extraction of Zn, Cu and Fe varies with Fe roasting temperature. The % extraction of Zn is maximum at 600°C, that of Cu is maximum at 550°C, and that of Fe is minimnm at 600°C.View full abstractDownload PDF (862K) -
[in Japanese]1949 Volume 65 Issue 739 Pages 403-413
Published: December 25, 1949
Released on J-STAGE: July 13, 2011
JOURNAL FREE ACCESSDownload PDF (2596K)
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