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Volume 52, Issue 12
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[in Japanese]1973 Volume 52 Issue 12 Pages 883-884
Published: December 20, 1973
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (2099K) -
Kojiro Kojima, Hiroshi Ogoshi1973 Volume 52 Issue 12 Pages 885-895
Published: December 20, 1973
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSWhen we attempt to predict coking properties of a coal by the petrographical method, sometimes we confused and got miss evaluation after the coal had been oxidized.
Japanese iron works used to employ many kinds of coals through all over the world which are more or less oxidized.
We studied transitions of physical and chemical properties of coals which were artificially and naturally weathered, especially from petrographical view point. The artificial weathered coals were prepared under air below of 70°C.
The results are as follows:
1) The “Reflectance” of Vitrinit decreased at the first time and then increased. The distribution of the “Reflectance” of a coal was spreaded.
2) The amount of the “Psudo-vitrinit” increased as the coals were oxdized.
3) The Volatile Matter decreases, Oxygen contents increase, the “Free swelling Index” decreases, moreover the “maximum fluidity” in a coals measured by “Giessler plastometer” remarkably decreases as they were weathered.
4) Cokes of weathered coal by microscopy, and noticed that the particles of the oxidized coal did not swell and did not adhere together.
5) By means of X-ray diffraction, the graphitization of the cokes from the low rank weathered coals decrease, but in the cokes from the high rank weathered coals this tendency can not be found.
6) We studied by means of the Infra-Red absorption, what kinds of chemical changs took place during weathering. The absorption of the wave number 1720cm-1 increased. This will indicate the increase of the amount of -C=0 bond.
7) The compensative calculation method to predict a coking property of a weath-ered coal11 from C/O ratio of elementary analysis has been veparted, but the oxygen analysis is uncertain, so we propose a following method: if we could exactly distinguish the “Psudo-Vitrinit” or oxidzed coal from the “Vitrinit”, so these “maceral” should be considered as “Inerts” and wecan predict the coking property more exactly. Now we measure the distributtion of the reflectances of a coal and the Vitrinit of which the reflec-tances are higher 0.2 than the mean reflectance of them should be considered as “Inerts”.View full abstractDownload PDF (1598K) -
Saturated Hydrocarbon FractionKazutoshi Imuta, Shiro Takahashi, Koji Ouchi1973 Volume 52 Issue 12 Pages 896-905
Published: December 20, 1973
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSHigh boiling fraction (265-316°C, 0.3 mmHg) of benzene extract of Yubari coal was fractionated by column chromatography and the saturated part was separated to urea adduct and to non adduct. The former is the n-paraffine mixture which contains C15 to C70, having a maximum at C35-C40. The latter is supposed to be mainly a mixture of isoprenoids of which the mean supposed structure is
CH3-(CH3-CH-CH2-CH2-CH2-) 5-CH3
The following fraction which has UV absorption of naphthalene nucleus, was examined by IR, UV, NMR and mass spectrum. The results of structural analysis of that fraction and of a supposed mean structure
coinside very well.
From the another lowest boiling fraction (-100°C, 4 mmHg) of benzene extract, adamantane was separated and confirmed. The amount of adamantane in the original coal is 0.16ppm.View full abstractDownload PDF (1267K) -
Susumu Yokoyama, Noriaki Ounisi, Gen Takeya1973 Volume 52 Issue 12 Pages 906-916
Published: December 20, 1973
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe present paper describes the structure of solvent fractionation products from coal to clarify the relationship of molecular structure and structural units of coal constitution.
Chloroform-soluble, petroleum ether-insoluble portion (γ2-4 part) of pyridine extract from akabira coal was separated into fractions according to their respective molecular weight by gel permeation chromatography (GPC) and the individual fractions obtained were analysed for structural units and molecular structure respectively using the results of high resolution NMR, elementary analyses and molecular weight. From these struc-tural analyses, the chemical structure of γ2-4 part were discussed.
Each fraction showed good separation as indicated by narrow elution curves by analytical GPC and has s molecuular distribution from high molecular weight (M: 1910) to low molecular weight (M: 310) by increasing the elution volume (Fr. No.) of prepa-rative GPC. It is obvious from the analyese of structural parameters of an average unit structure which have approximately the same values except for the high molecular weight fraction, that each fraction consist of a constitution having a structural unit of homologus chemical structure.
And also by taking into account the results of molecular weight, the average molecular structure f or each fraction were analysed. It was shown thown that the various structural parameters for aromatic rings and aliphatic structure substituted to aromatic rings per molecule increase gradually according to the shift from low molecular constitu-tions to high molecular constitutions.
From these structural analyses, it may be said that the constitution of γ2-4 part consists of 2 or 3 aromatic rings which were substituted by the number of 2 or 3 aliphatic side chains having 3 carbon number in chain lengtn as its unit structure and were bounded repeatly by the number of 2 to 4 of these unit structures.View full abstractDownload PDF (1398K) -
Yoshihisa Hasegawa, Shigeru Ueda, Yosuke Maekawa, Toshio Sato1973 Volume 52 Issue 12 Pages 917-925
Published: December 20, 1973
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDetermination of organic oxygen in coal is specially important for advanced utilization of coal. However, the direct and indirect analyses conventionally used are not always reliable presumablly because of the thermal decompofition of ash in coal in the processes of the analyses. The present investigation has been carried out to establish an accurate determination of organic oxygen in coal by using a low temperature asher which has recently been developed.
A IPC model 1101 plasma asher was used for this pwrpose and the fast neutron activation analysis and the thermal decomposition method were used for the determination of oxygen content. First, several clay minerals and their mixtures with pure carbon wese treated in a stream of oxygen plasma in a total high frequency power range between 200 and 900 watt for six sample chambers. The reaction temperatures were deduced by checking melting point of pure substances in amples under the similai reaction conditions.
From these results and also results on the differential themal and the products, it was conclusively found that the oxygen flow rate of 600 ml/min and the high frequency power of 600 watt were most snitable for complete oxidation of organic matter without prodneing the thermal decomposition of ash in coal and organic oxygen content of coal was accurately determined as the difference beween the total oxygen content of coal and the oxygen content of ash in the coal.View full abstractDownload PDF (1278K) -
Yohichi Gohshi, Kenjiro Yanagase1973 Volume 52 Issue 12 Pages 926-931
Published: December 20, 1973
Released on J-STAGE: February 23, 2011
JOURNAL FREE ACCESSChemical states, especially oxidation states, are knowm to have various effects on x-ray spectra from sulfur. The efiects, however, are not large and it is rather difficult to observe them with a conventional commercially available x-ray spectrometer. A high resolution two-crystal x-ray spectrometer recently constructed was used for the observation of these phenomena in order to utilize them for the chemical state analysis of sulfur in coal.
Pressed samples were excited with x-rays from a Cr target tube. Resultant fluorescent x-rays (SKα) were analyzed with the two-crystal spectrometer (prototype of Toshiba AFV 701) equipped with Ge (111) or ADP (101) crystals. A gas flow proportional counter was used as a detector. Pulses from the detector were stored in a multichannel pulse height analyzer (multiscaler mode. In case of a low intensity, the spectrometer was scanned repeatedly and pulses were accumulated several times.
The energy of SKα increases with the increase of oxidation number. The spectrum from Na2S2O3, which contains S2- and S6+, shows two components which correspond to S2- in FeS and S6+ in Na2SO4. This fact means that qualitative and quantitative chemical state analyses can be performed by measuring SKα spectra precisely.
SKα from coal has a strong peak and a weak shoulder which is on the short wavelength side of the intense main peak. These two components were concluded to be due to S2- and S6+ by comparing their positions with the spectra of known compounds.
Ouantitatne analyses of S2- and S6+. were performed with a non-linear least square method. The result for variaus coals were discussed (total S: 0.6-3. 3%, S6+: 5-28).View full abstractDownload PDF (772K) -
Hiroshi Tsukashima, Tsutomu Kato, Susumu Odera, Yasuo Ohashi1973 Volume 52 Issue 12 Pages 932-944
Published: December 20, 1973
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe present report deals with the carbonization of coals such as Tempoku coal (C%, 71. 8), Taiheiyo coal (C%, 77.5) and Yabari (C%, 84. 3) at about 20, 600, 800, 1000 kg/cm2 in order to examine the effects of carbonization pressure.
From the results of proximate analyses, ir analyses, x-ray diffraction analyses, nmr measurement and structural analyses using densimetric method of carbonization products and their pyridine extracts andresidues, it proved that carbonization products of both Tempoku coal (low rank coal) and Y-abari coal (coking coal) were affected by carboni-zation pressure, and that the latter was more sensitive under high carbonization pressure.
In the case of Tempoku coal, the yield and the aromaticity varied under high carbonization pressure while the volatile matter did not changs. Then it would actually be difficult to find what parts of the coal substances had been affected carbonization pressure.View full abstractDownload PDF (1707K)
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