ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1983.tb04590.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARYFluorescence analysis of the liptinite maceral content of various U.S. coal seams has shown that these macerals are consistently under‐counted in conventional white‐light analysis. Fluorescence analysis revealed a greater variety of liptinite macerals as well as a large amount of fluorescing vitrinite in all of the coals studied. However, pseudovitrinite was not observed to fluoresce. Textures and structures not visible in normal viewing are also seen in fluorescence analysis. Quantitative spectral analysis of single coals has shown that most liptinite macerals can be both petrographically and statistically separated on the basis of fluorescence parameters, with the wavelength at maximum intensity and the red/green quotient being the most significant. In coals of the Illinois Basin, one or more forms of fluorinite, resinite, sporinite and cutinite can be distinguished.As the rank of the coal increases, the fluorescence intensity decreases and the spectral maxima shift toward longer wavelengths. In some Rocky Mountain coals these effects occur at a much lower rank (<0.85% reflectance) than in the coals of the Appalachian Basin. Similar changes in fluorescence properties have also been found in naturally weathered coals. Fluorescence analysis of resinite‐rich Rocky Mountain coals has shown that two major forms of resinite are present; one is the ‘normal’ resinite, and the other is a much more abundant fissure‐filling resinite that carries coal xenoliths, shows flow structure, and has a spectral maximum well below that of the ‘nor

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1983.tb04591.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARYRodlets from fusain and carbominerite bands or lenses in bituminous coal beds of the central part of the Appalachian coal field in the eastern United States were studied in three dimensions using both light microscopy and scanning‐electron microscopy (SEM). Infrared studies and chemical analyses complemented reflectance measurements. The rodlets are found strati‐graphically from the Pocahontas no. 3 coal bed (Pocahontas Formation, Lower Pennsylvanian or Namurian B&C) to the Washington coal bed (Washington Formation, Lower Permian). The most common rodlets are noncellular, range in diameter from 60 to 440 μm, and, when polished, have the relief and high reflectances typical of the inertinite maceral group. They have characteristic notches, ovoid shapes, distinctive fracture patterns, dense (oxidized) rims, vesicles, cavities and canals, some of which contain minerals (tentatively identified by SEM semiquantitative X‐ray and infrared analyses). Some rodlets show a cellular cast on their longitudinal surfaces. Due to different exposures in variously‐oriented polished sections, this type of rodlet is classified as sclerotinite of the inertinite maceral group. Comparison of the sclerotinites from the central part of the Appalachian coal field with the fusinitized resin rodlets from coal and coal balls of the Illinois basin (Kosanke&Harrison, 1957) and with the ‘sclerotioids’ of the St Rose no. 5 coal of Nova Scotia indicates that they represent the same bodies. All are interpreted to be rodlets of resinous origin belonging to one or more of the genera of medullosan seed ferns of Carboniferous and Permian age. We suggest using the existing terms ‘resino‐sclerotinite’ and ‘fungo‐sclerotinite’ for two distinct maceral varieties of the inertinite maceral group because of their distinguishing properties and their different paleobotanical origins. Two types of cellular rodlets, woody splinters and sclerenchyma strands, are also documented in this study because of their close association with the resino‐sclerotinites of the central part of

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1983.tb04592.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARYThis paper reports a systematic study of variation of morphological and optical properties of low and medium rank sporinites (carbon = 830 and 87.1% d.a.f.) and vitrinites (carbon = 79.6 and 86.6% d.a.f.) of same coals carbonized over temperatures ranging from 300 to 950°C for 1 h at a heating rate of 5°C/min in an atmosphere of nitrogen. Contrasts are drawn between the molecular structure of carbonized residues of sporinites and vitrinites of the same coal based on variation of morphological and optical properties. For the same carbonization conditions, carbonized residues of sporinites eventually develop better ordered molecular structures than do the carbonized vitrinites, due to the greater level of fluidity of sporinite than vitrinit

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1983.tb04593.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARYA classification for the carbonaceous solid residues from coal hydrogenation is proposed, based on that introduced by Mitchellet al.(1977). A more precise and restricted definition is applied to the proposed terminology. This systematic classification may lead to a better understanding of the dissolution and thermal alteration of macerals in a closed system and should also ensure meaningful comparisons between quantitative point count data.

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1983.tb04594.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARYThe capabilities of Rapid Scan, a system of automated reflectance microscopy, has been extended to the actual mapping of petrographic variation across polished coal surfaces. This is accomplished through computer control of a microscope stepping stage and the storage of binary reflectance data on disc in a matrix form which permits the proper spatial arrangement of values to be re‐created. The maps depict lithotype variation, and the distribution of mineral occurrences, cracks and cleat. An image processor can be employed in further map analysis such as the compilation of reflectance profiles from selected area

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1983.tb04595.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARYPrimary or True QIs, and also the so‐called ‘dirt’ were separated from seven tar sources available in Canada from four different steel companies, by filtering hot tar solution of quinoline and other good solvents. After washing with quinoline and acetone and drying, the filter cake was examined under scanning electron microscope (SEM) and analysed for inorganic impurities by wave length and energy dispersive X‐ray spectrometers. A limited amount of work was carried out on a production pitch blend, utilizing optical microscopy.After the filtration process, the filtrates which represented the QI free tars were subjected to distillation at atmospheric pressure and various pitches were prepared with a softening point range of 70–100°C. The pitches were dissolved in quinoline and analysed for QIs. The small amount of QI from each pitch was extracted and dispersed with solvent onto a microscope slide. The samples then were subjected to SEM and in one case to optical microscope studies; the sizes and shapes of the QIs were determined and compared with the QIs originally found in the individual tars. Photographs have been taken during the scanning work to record findings which have been considered typical and demonstrative of the findings.In order to gather further information on the role of QI in tars and pitches, particle size distribution was determined of QI extracted from a tar and a production pitch by a Coult

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1983.tb04596.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARYThermal processing of coal and coal products can lead to the formation of ordered carbons through the mesophase mechanism. The performance characteristics of metallurgical coke may be improved by the extent of this ordering; however, in the direct hydroliquefaction of coals the objective is to make species of low molecular weight, and coking is an undesirable retrograde reaction. This study is concerned with fundamental mechanisms of coke formation and their roles in these two processes.Most studies of mesophase formation have involved the heat treating of samples followed by quenching and examination at room temperature. This project has used hot‐stage microscopy and the production of a 16‐mm colour film to study the dynamics of mesophase growth and coalescence.Various solvent‐refined coal (SRC) and SRC fractions were carbonized in gold tubes at 450°C and 34.5 MPa, and the pyridine‐insoluble fractions (semi‐coke) examined microscopically. Greater molecular mobility, manifested by lower proportions of anisotropic carbon and larger domain sizes, was evident for SRCs which had undergone more extensive hydrogenation at the pilot plant, and for SRC fractions of lower functionality.The performance of metallurgical coke in the blast furnace can be related to its inherent carbonaceous structure. Coals which give cokes of marginal quality include low‐rank bituminous coals which form an optically isotropic coke. One method of improving the carbon ordering in these cokes is the use of a carbonizing additive. In this study SRC was used as the additive, giving improvements in the coke structure and mi

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1983.tb04597.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARYThe importance of the porous structure of coke in industrial usage has been recognized for many years but the difficulties involved in determining by manual microscopic methods, quantitative details of the structure precluded comprehensive and detailed studies. With the advent of computerized image analysis systems it has become possible to overcome many of the practical difficulties associated with the determination of structural data for a material as heterogeneous as metallurgical coke. Techniques based on reflected light microscopy and automatic image analysis have been developed to the extent that representative and reliable structural characterization of coke can be achieved. The data so obtained have been used to derive strength/structure relationships which enable coke strength to be predicted with a standard error comparable with that of the experimental determination and the structural characterization now offers an additional means of defining coke quality with potentially significant industrial applications.

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1983.tb04598.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARYPetroleum pitches on carbonization form anisotropic cokes. Structure in these cokes is dependent upon the method of carbonization. For example, the delayed coker can produce needle‐cokes from suitable feed‐stocks. Structure in cokes cn be studied as the optical texture of polished surfaces using optical microscopy, the optical texture being descriptive of macro‐crystallinity within the coke. These polished surfaces of cokes when studied using polarized light indicate the orientation of the constituent lamellar molecules of the macrocystallinity to the plane of the polished surface. This approach has limited application in assessments of structure in three dimensions. The study describes how the techniques of etching of polished surfaces of coke, mapped initially by optical microscopy, using a solution of chromic acid followed by examination of the same area by scanning electron microscopy, reveals structure in anisotropic

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1983.tb04599.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY