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Volume 58, Issue 2
Displaying 1-11 of 11 articles from this issue
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[in Japanese]1979 Volume 58 Issue 2 Pages 63
Published: February 20, 1979
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (224K) -
Chikao YOKOKAWA1979 Volume 58 Issue 2 Pages 64-74
Published: February 20, 1979
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSReview and digest of the preceeding literatures were made in order to demonstrate a physico-chemical aspect of coals.
Appearent density, porosity and specific surface area were considered at a stand point of the way of constructing the coal matrix. True density, reflectance and hardness were regarded, in a connection with their ultimate composition, as functions reflecting the chemical structure of coal molecule. Thermo-plasticity were discussed with solvent-extraction experiments and with chemical constitution for a general understanding of the caking property of coal.
Chemical reactions such as oxidation, pyrolysis, hydrogenolysis and depolymerization were outlined and specific behaviours of various coals of different ranks were discussed.View full abstractDownload PDF (1630K) -
Hideo KIMURA1979 Volume 58 Issue 2 Pages 75-89
Published: February 20, 1979
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSAuthor described the method of petrographic constituent analysis, some property of macerals and the application of coal petrology for fundamental research or industry.
The methods of microscopical measurement for the macerals and reflectance of coal are now studying at the Japanese Committe on coal petrology in the Japan Iron and Steel Federation for the Japanese Industrial Standard (JIS).
Research on the property of macerals of Japanese coal and imported coal is specially important for a prameter both coal rank and caking property in coke industry.View full abstractDownload PDF (3404K) -
Takashi MIYAZU1979 Volume 58 Issue 2 Pages 90-101
Published: February 20, 1979
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThis paper reviews on the problems or difficulties of analysis or testing methods of coal. The main ietms discussed in the neview are as follows;
1) Gemerally speaking, most of the characteristics of coal are the function testing conditions, such as apparatus or prcedures, because no “true value” exists substantially in coal analysis or testing, excluding ultimate analysis. For example, therefore, the testing conditions of “proximate analysis ”should be specified more strictly compared to that of “ultimate analysis, ” because, volatile matter or ash contents can be variable according to the change of specification of analytical method. On the other hand, there are some degrees of freedom on the specification of testing conditions of ultimate analysis, because, the calibrating system using standard substances can be employed in these kinds of analysis method.
2) TIS M8810-8815, M8801 (Analysis and testing of Coal and Coke) are superior standards compare to that of most of the foreign countries, nevertheless, they are not always “reference methods”, but still industrial standards. The specified procedure of them, therefore, should be followed strictly for the commercial use, however, it does not necessarily when the more accurate and precise results are required in such a case of studies of coal.
3) The difference of “caking property” and “coking property” should be noted strictly on the dis cussion of characteristics related to the coking industry, because some confusion has been observed in the former papers. In addition, the use of Signal-Noise ratio as a statistical criterion is recommended for evaluating the sensitivity of the above testing methods.
4) The relationships between many kinds of “caking properties” are discussed and nlotled in the atlached figures.View full abstractDownload PDF (1458K) -
Ryohei TAKAHASHI1979 Volume 58 Issue 2 Pages 102-111
Published: February 20, 1979
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSBecause the coal is composed of several macerals which altered in multifarious grades during the coalification process divided into two stages, bio- and dynamo-chemical one, coals of really manifold physico-chemical natures turn up, according to assemblage of macerals and to degrees of their alterations. Due to recent artificial coalification experiments dynamo-chemical process is governed primarily by temperature and the time during which plant materials were heated, and pressure retards such reactions.
The same maceral in the same coal seam must have experienced the same dynamochemical reaction through the geological progress, it is, therefore, hardly possible to explain existences of the same macerals having different physico-chemical properties, and also of vitrinite and fusinite which are originated equally from woody materials. Intensity of degree of alteration of maceral in the biochemical stage must be accordingly evaluated more seriously.
As biological reactivities in this stage are essentially influenced by geographical and geological circumstances of the depositional basins like as location or movement of the basin, height or nature of ground water, etc, occurence of coal basin is discussed from geotectonical point of view, and coalification process and resulted natures of coals in respective type of basins are also mentioned.
From such discussion and consideration, characteristic nature of Japanese coal may be quite well understood.View full abstractDownload PDF (2105K) -
Yoshiaki MIURA1979 Volume 58 Issue 2 Pages 112-122
Published: February 20, 1979
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSWeathering of coal during storage is an old problem which still remains today from the aspect of coal utilization. Description herein is mainly centered on the weathering phenomena of coking coal during storage and transportation, properties of weathered coal, factors and mechanism of weathering, heat generation in coal pile due to weathering, storage practice and testing method.
A brief description is also given of weathered coal in outcrops of newly developed overseas coal fields.View full abstractDownload PDF (1632K) -
Kinji HOSHIZAWA, Tohru SEMA1979 Volume 58 Issue 2 Pages 123-140
Published: February 20, 1979
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThis paper deals combustion engineering research of coal and prevent air pollutants for thermal power plants. The outline of pulverized coal conbustion engineering is mainly described. Further, in new combustion engineering which will put to practical use in near future, fluidized bed combstion method and coal-oil slurry are described.View full abstractDownload PDF (2359K) -
Yoshiro MORITA1979 Volume 58 Issue 2 Pages 141-147
Published: February 20, 1979
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThis paper is an educational article of coal gasification. Basic reac-tions of coal gasification are classified into thermal cracking, hydrogasification, hydro-methanation, water gas reaction, producer gas reaction and combustion. Concerning each reaction, theoretical treatments on the effects of pressure, temperature and volume of chemical spesies are elucidated. These treatments are applied to illustrate the chemical changes in three types of simplified furnaces of perfect coal gasification, hydrogasification and gasification with desulfurization.View full abstractDownload PDF (1083K) -
Yoshiko KAMIYA1979 Volume 58 Issue 2 Pages 148-157
Published: February 20, 1979
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSOxidation reaction of coal at relatively high temperatures were reviewed from the view point of reaction chemistry.
In the gas phase reaction, coal can be oxidized by mostly dehydrogenating mechanism being quite different from the liquid phase reaction due to free radical mechanism, because coal contains many kinds of easily oxidizable structures as well as many oxidation inhibiting structures.
In the liquid phase reaction, coal is oxidized and dissolved into solution as the high molecular weight compounds so called humic acids, which were further oxidized rather slowly to the lower molecular weight aromatic polycarboxylic acids.
The oxygen-oxidation of bituminous coal in alkaline medium results in a good yield of water-soluble aromatic polycarboxylic acids composed of mostly benzene polycarboxylic acids as the functions of alkali concentration and coalification grade of coal.
Nitric acid oxidation of bituminous coal at high temperatures or with concentrated nitric acid also results in a good yield of acid-soluble aromatic carboxylic acids.View full abstractDownload PDF (1428K) -
Hironori ITOH, Koji OUCHI1979 Volume 58 Issue 2 Pages 158-173
Published: February 20, 1979
Released on J-STAGE: October 21, 2011
JOURNAL FREE ACCESSBasic studies on coal hydrogenolysis and hydrogen donor solvent liquefaction of coal were reviewed.View full abstractDownload PDF (2354K) -
Yuji YOSHIDA1979 Volume 58 Issue 2 Pages 174-179
Published: February 20, 1979
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSFundamental reactions and phenomena in coal carbonization process are reviewed mainly from the view point of coke making. Mechanism of coal pyrolysis, especially formation of tar and gas, was described and changes in the yield and composition of gas with the rank of coal and carbonization temperature were explained.
Strength of coke is influerced not only by caking properties of coal, but also by fissures produced during coking, which depend on the rank of coal, i.e, volatile mattcr content of coal. Blending theory for making hard coke was briefly summarized.View full abstractDownload PDF (825K)
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