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Volume 47, Issue 12
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[in Japanese]1968 Volume 47 Issue 12 Pages 839
Published: August 20, 1968
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (193K) -
Atuo Aihara1968 Volume 47 Issue 12 Pages 840-847
Published: August 20, 1968
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe rise in the rank of coal toward the north where the Ishikari group increases in total thickness within the western wing of the Sorachi anticline have been recognized, and this tendency could be applied to the Noborikawa coal-bearing formation, the lowest of the Ishikari group, and to the Bibai coal-bearing formation that lies about the middle of the group, both of which are the major coal-bearing formations in Sunagawa region, the central part of the above mentioned.
The increase in C percentage per 100 meter coverage of coal seams have been clarified to be 1. 5% in average when calculated individually in the two coal-bearing formations. Consequently, the depth of the coverage is considered to be major factor holding a prominent position in the T. P. conditions in accelerating the degree of coalification. However, should it be so, Noborikawa, in contrast with Bibai, should be much higher in rank.
The cause of the approximation of the rank of coal in the two coal-bearing formations is discussed geologically in the text, and it could be considered that the thickness of each formation thins toward the axis of the Sorachi anticline, resulting in the coverage of the Noborikawa coal-bearing formation becoming near equal to that of the Bibai coal-bearing formation.View full abstractDownload PDF (1214K) -
On the Mechanism of Fine Grinding of CoalToshihiko Maruyama1968 Volume 47 Issue 12 Pages 848-855
Published: August 20, 1968
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe compressive strength have been measured on irregular shaped coals ranging from 0.1mm to 2.0mm particle size for low ash coals in Hokkaido. The results obtained from these experiments and those obtained from the silica ball-mill grinding test for the same coals are summerized as follows:
1) There are linear relationships between mean compressive strength and mean particle size of coals, and the extent of the effect of particle size on the compressive strength increases with increase of H. I.(Hardgrove index) (Fig. 2 and Table 1)
2) The size distribution of broken coals by static compression correlates to M. I. of coals tested.(Fig. 3)
3) For coals showing high H. I. as Naie coal, the weakest link theory could be appricable to the compressive breakage of irregular shaped coals in the range of these particle size. However this theory should not be applicable to coals showing low H. I., because the amount of cracks and flaws in these coals are not so much.
4) Rate of grinding, except for two coals, is approximately proportional to H. I.(Fig. 9)
5) In case of ball-mill grinding, the mode of breakage of low coals under compressive stresses is taking place through breaking process among each coal particles. Under the same grinding condition, the size distribution pattern of ground coals varies with increasing H. I. from the surface grinding pattern to the bulk crushing pattern.
6) Wear of silica balls in the ball-mill grinding decreases rapidly with increasing H. I. up to about 60, and then decreases slightly.(Fig. 10)View full abstractDownload PDF (1023K) -
Hideo Ohuchi, Toshiro Isobe, Junkichi Sohma1968 Volume 47 Issue 12 Pages 856-863
Published: August 20, 1968
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe electrical conductivity of the several Hokkaido coals was measured at room temperature and during heat treatment (see Fig. 2, 3 and 4). The mechanism of electrical conduction in coal was discussed combining the above data with the Eley's tunnell theory which was used to explain electron transport in the organic compounds. From the discussion, the models of the structural units in coals were presented as showed Fig. 8 and 9.View full abstractDownload PDF (1062K) -
Thermo-Plasticity of CoalHidehiko Sugimura, Yoshihiro Osawa, Akira Ikutaand, Hidemasa Honda1968 Volume 47 Issue 12 Pages 864-871
Published: August 20, 1968
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe Thermo-Plasticity of vitrains of five Japanese caking coals and four foreign caking coals have been examined from the ordinary A. S. T. M. test and some other fluidity measurements with the Gieseler plastmeter.
The temperatures showing initial softening, fusion, maximum fluidity and solidification increases with rank of coal.
The fluidity of Japanese coals is higher than that of foreign coals at about same rank. And the coal at about 86 percent carbon content has a maximum fluidity.
This shows that the greater the content of tar and/or liquid-forming constituents in coals is.
Around the initial softening point, the fluidity of coals hardly changes and shows an almost constant value for a long residence time at constant temperature.
Around the fusion point, the fluidity of Miike coal (84.5%C) and Yubari coal (86.2%C) exceptionally increases with residence time up to about 150 minutes and then becomes almost constant up to 250 minutes. Flow curves for these coals at constant temperatures below the fusion points, obtained by measuring fluidities over a range of shear stress, indicate that these coals behave substantially as a plastic fluid.
Above the fusion point, the fluidity of coals increases steeply at first, shows a maximum, and then decreases with increase of residence time at constant temperature.
The time getting to the maximum fluidity increases with rank of coal at a constant temperature and decreases with increase of carbonizing temperature.View full abstractDownload PDF (940K) -
V ariation of ESR at the Early State of CarbonizationChikao Yokokawa1968 Volume 47 Issue 12 Pages 872-879
Published: August 20, 1968
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSNine vitrains (72. 7-90.7%C) were carbonized up to the temperatures between 320 and 600°C in a step of 20°C. The temperature was rised at the rate of 3°C/min. and the final temperature was kept for 10 minutes. The chars thus obtained were examined by X-band ESR spectrometer. ESR spectra were observed in vacuum (10-4-10-5 torr.), in air, in ethylene diamine after heating with it at 180°C and in air after washing with methanol and hydrochloric acid. Spin concentration (No.of spin/g of char) increased with rising temperature and it was noticed that the increase in spin concentration took place considerably even at temperatures as low as 320-380°C where no appreciable weight loss was observed by thermogravimetry. All of the chars, excepting these obtained at temperatures above 540°C, decreased their spin concentration when they were heated with ethylene diamine and the ΔHmsl observed in ethylene diamine kept constant value for each individual vitrains while the ΔHmsl observed in vacuum varied considerably. By washing the chars heated with ethylene diamine the spin concentration was recovered almost quantitatively for the chars obtained at temperature above 460°C, but not quantitatively for the other chars. It was observed that the recovery of spin concentration seemed difficult for some of chars which were obtained at temperatures between 400 and 440°C.
It was assumed that the increase in spin concentration which was observed at low temperatures took place as a result of coming loose of the low molecular materials, on the analogy of the fact that chloroform-extract increases at the temperature. The spin centres which form and exist at temperatures below 500°C were considered to be similar to those exist in original coal in nature although as temperature gets near 500°C they vary gradually. It would be concluded that the spin centres of coal, especially of bituminos coal, are aliphatic or alicyclic in natue at temperatures below 500°C and above 500°C they become aromatic in nature.View full abstractDownload PDF (1084K) -
The Study of Fine Structure of Coals-Density of Coals Measured with Various Liquids?Yuzo Toda, Yuji Yoshida, Hidemasa Honda, Masao Hatami1968 Volume 47 Issue 12 Pages 880-887
Published: August 20, 1968
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDensity of twelve Japanese coals and five foreign coals including wide range of carbon content were measured with methanol, n-hexane and mercury as replacing liquids.
Discussion was done about pore volume of coals from both densities including helium densities (measured by Fujii et al.) and adsorption of carbon dioxide interpreted by Dubinin-Polanyi's equation.
Densities with methanol are the highest in all the coals investigated except a few coals, difference of which are considered to be experimental error.
Apparent excess of methanol densities from helium densities were too large to interprete it ascontraction or adsorption effects of methanol in pore structure of coals.
It was suggested that its excess result from both activated diffusion effect of helium molecules to coal structure and opening of closed pores by swelling effect of methanol.
It was concluded from the data of the pore volume of coals calculated frodensity, carbon dioxide adsorption and density drift in methanol and in n-hexane that mean pore diameter of coals increase with increasing the rank of coal to about 85% carbon content, reaching maximum, and decrease with increasing the rank of coal.View full abstractDownload PDF (949K) -
Kazutoshi Imuta, Koji Ouchi1968 Volume 47 Issue 12 Pages 888-893
Published: August 20, 1968
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe petroleum ether-soluble fraction of Tempoku brown coal depolymerized in phenol with p-toluene sulphonic acid as catalyst was methylated and then fractionated by liquid chromatography. 9-(2-methoxyphenyl)-xanthene, 2-(4-methoxypheny1)-benzofuran, 9-(4-methoxypheny1)-xanthene, xanthone and other four drystalline substances were isolated.View full abstractDownload PDF (701K) -
Seiji Nishida1968 Volume 47 Issue 12 Pages 894-899
Published: August 20, 1968
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSCation exchange properties of several kinds of humic acid were studied in the range of 1/10N-1/2, 000N of metal salts in aqueous solution.
In high concentration of metal salts in aqueous solution, humic acid extracted from HNO3-oxidized coals has more exchange capacity than that obtained from O2-oxidized coal, however, in low concentration of their aqueous solutions, later has more exchange capacity than the former. Variation of KNiH with the concentration of NiCl2 showed that the cation exchange property of humic acids extracted from oxidized coals was different from that of cation exchange resin Amberlite IRC-50. It was found that in low concentration of metal salts in aqueous solutions, the exchange capacity of humic acid obtained from oxidized coals was in order of transition metal<alkaline earth metals< alkaline metal. Carboxyl acidity of O2-oxidized coals was in linear relation with their Ni uptake in 1/1, 000 N NiCl2 in aqueous solution. This result seemes to show that carboxyl groups take part in Ni uptake reaction in ever low concentration of NiCl2 aqueous solution.
These results suggest that coal oxidation products have carboxyl groups to be able to form chelates and exchange cation. As O2-humic acid is better than the other samples in this capacity, it has more metal uptake in low concentration of metal salts in aqueous solution.View full abstractDownload PDF (730K) -
1968 Volume 47 Issue 12 Pages 904-906
Published: August 20, 1968
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (412K)
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