1、Designation: D2799 11D2799 12Standard Test Method forMicroscopical Determination of the Maceral Composition ofCoal1This standard is issued under the fixed designation D2799; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the equipment and techniques used for determining the physical composition of a coal sample
3、 interms of volume percent of the organic components and of mineral matter, if desired.1.2 The term weight is temporarily used in this test method because of established trade usage. The word is used to mean bothforce and mass and care must be taken to determine which is meant in each case (the SI u
4、nit for force is newton and for mass,kilogram).1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regul
5、atorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D121 Terminology of Coal and CokeD2797 Practice for Preparing Coal Samples for Microscopical Analysis by Reflected LightD2798 Test Method for Microscopical Determination of the Vitrinite Reflectance of CoalD3174 Test Method for
6、 Ash in the Analysis Sample of Coal and Coke from CoalD3177 Test Methods for Total Sulfur in the Analysis Sample of Coal and Coke (Withdrawn 2012)3E177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study to Determine the Precisio
7、n of a Test Method3. Terminology3.1 DefinitionsFor definitions of terms, refer to Terminology D121.3.2 ClassificationThe classification of the microscopic constituents into groups of similar properties in a given coal is asfollows:Maceral Group MaceralVitrinite Liptinite or (exinite) alginitecutinit
8、eresinitesporiniteInertinite fusiniteinertodetrinitemacrinitemicrinitefunginitesecretinitesemifusinite1 This test method is under the jurisdiction ofASTM Committee D05 on Coal and Coke and is the direct responsibility of Subcommittee D05.28 on PetrographicAnalysisof Coal and Coke.Current edition app
9、roved April 1, 2011Sept. 1, 2012. Published April 2011January 2013. Originally approved in 1969. Last previous edition approved in 20102011 asD2799 10.D2799 11. DOI: 10.1520/D2799-11.10.1520/D2799-12.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service
10、 at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the u
11、ser of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard
12、as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.3 Many laboratories associated with the coke-making industry use the following simplified classification for petrographic
13、analysis of bituminous coal:vitriniteliptinite (other than resinite)resinitesemifusinitemicrinitefusinitemineral matter3.4 Definitions of Terms Specific to This Standard:3.4.1 alginite, na liptinite maceral that is generally spherical or ovoid, frequently having a crenulated border and somewhatirreg
14、ular reflectance and sometimes occurring in clusters reflecting an origin from Botryococcus algae.3.4.1.1 DiscussionAlginite often occurs as degraded fragments derived from colonial or unicellular bodies.3.4.2 cutinite, na liptinite maceral in the form of a sheet reflecting its origin from leaf- or
15、twig-covering plant cuticle,frequently exhibiting reticulation in planar section and a serrated edge in cross section.3.4.3 exinite, nDeprecated term. Use preferred term liptinite; sometimes has also been used as a synonym for sporinite.3.4.4 funginite, nan inertinite maceral occurring as round or o
16、void bodies, frequently containing voids, reflecting an originfrom fungal sclerotia; also occurs (especially in lower rank coals) as interlaced, stringy materials derived from fungal hyphae.3.4.5 fusinite, nan inertinite maceral distinguished principally by the preservation of some feature(s) of the
17、 plant cell wallstructure, and with a particle size greater than 50 m except when it occurs as a fragment within the binder matrix; see alsosemifusinite.3.4.6 inertinite, nmacerals that exhibit higher reflectance than other organic substances in the coal.3.4.6.1 DiscussionIn any coal ranked lower th
18、an anthracitic, inertinite reflectance commonly spans the range from only slightly higher than associatedvitrinite to very high reflectance (often as high as Romax 6 %). In anthracitic rank coals, inertinite reflectance may be lower thanthat of vitrinite, and is then recognized by its morphology and
19、 form of anisotropy. Highly reflecting inertinite commonly exhibitsrelief on polished surface. Its name derives from the fact that most varieties behave inertly in the thermoplastic deformation duringthe coking process (except in its lowest reflecting manifestation). The volatile matter yield of ine
20、rtinite is lower than that of othermacerals in the same coal.3.4.7 inertodetrinite, nan inertinite maceral occurring as individual, angular, clastic fragments incorporated within the matrixof other macerals (commonly vitrinite) or minerals, and in the size range from 2 to 50 m.3.4.8 liptinite, nmace
21、rals that exhibit lower reflectance than other organic substances in a coal, appearing black to dark grayand that fluoresce under blue to ultraviolet light in coals ranked high volatile bituminous and lower.3.4.8.1 DiscussionThe fluorescence of liptinite distinguishes fine-grained liptinite from sim
22、ilar sized, low reflectance, nonfluorescing clay minerals.Liptinite is derived principally from lipid substances forming skins (exines) and resinous secretions or exudates of plants. Liptiniteis sub-classified on the basis of morphology inherited from plant structure. In coals in which vitrinite ref
23、lectance exceeds about1.4 %, liptinite can be indistinguishable from vitrinite. Liptinite has the highest volatile matter yield of the macerals in a coal.3.4.9 maceral, nan organic substance in coal that is distinguished and classified (see maceral classification) on the basis ofits optical microsco
24、pic properties.3.4.9.1 DiscussionMacerals originate from plant tissues, secretions, and exudates that have been altered by geological processes and may contain upto several weight percent of inorganic elements in microscopically indistinguishable form.3.4.10 maceral classification, nThe systematic d
25、ivision of the organic substances (macerals) in coal based on their appearancein the optical microscopic.D2799 1223.4.10.1 DiscussionAlthough macerals may be identified in translucent, thin sections using criteria not defined herein, this test method deals only withidentification and classification
26、based on microscopic appearance on polished surfaces according to Practice D2797. Three majormaceral groups are recognized on the basis of relative reflectance in white light, specifically: vitrinitemoderately reflecting(intermediate gray), liptinitepoorly reflecting (black to dark gray), and inerti
27、nitehighly reflecting (light gray to white). Eachgroup can be subdivided on the basis of other microscopically distinctive features such as: reflectance contrasts (relative shadesof gray); morphology, that is, shape and size (morphologic distinctions in definitions contained herein are idealized bec
28、ausemorphologic appearance depends on the initial form of the source material, its state of preservation, including granulation, and onthe orientation of the cross section presented on the polished preparation); spatial association with other substances; fluorescenceproperties (color, intensity) in
29、blue to ultraviolet light; relief; color tinges; internal reflections; and anisotropic properties.Microscopic criteria provide classification capability without any implication of absolute chemical composition or physicalbehavior, although some properties relative to other macerals in the same coal
30、can be inferred broadly. Substances classified as thesame maceral by microscopic criteria can differ chemically, physically, and behavioristically in coals of different ranks. Someproperties can be estimated by the measurement of reflectance (Test Method D2798).See 3.3 for the classification used by
31、 most practitioners of this test method.3.4.11 macrinite, nan inertinite maceral, generally nonangular, exhibiting no relict plant cell wall structure and larger than 10m.3.4.12 micrinite, nan inertinite maceral, generally nonangular, exhibiting no relict plant cell wall structure, smaller than 10m
32、and most commonly occurring as particles around 1- to 5-m diameter.3.4.13 mineral matter, nin coal, historically considered to be the non-organic fraction composed of physically discreteparticles of minerals, such as clays, quartz, pyrite, etc., and all elements other than, carbon, hydrogen, oxygen,
33、 nitrogen, and sulfurin the organic fraction.3.4.14 resinite, na liptinite maceral occurring as rounded, ovoid, or rod-like bodies assuming the shape of an enclosing celllumen or as irregular shapes filling cracks in the coal.3.4.15 secretinite, nan inertinite maceral occurring as round, ovoid, or o
34、blong bodies, without obvious plant structure,vesicled to non-vesicled, sometimes containing characteristic fractures, slits, or a notch.3.4.15.1 DiscussionSecretinite is considered to be derived by the oxidation of plant resin secretions or humic gels. Vesicular and non-vesicularsecretinite was for
35、merly included in sclerotinite of fungal origin. Secretinite is a common maceral in medium- and high-rankPermian and Carboniferous coals.3.4.16 semifusinite, nan inertinite maceral with morphology like fusinite sometimes with less distinct evidence of cellularstructure, but with reflectance ranging
36、from slightly greater than that of associated vitrinite to some value intermediate to that ofthe brightest fusinite. The particle size is also greater than 50 m except when it occurs as a fragment within the binder matrix.3.4.16.1 DiscussionThe precise reflectance boundary between semifusinite and f
37、usinite has not been universally defined, although some practitionersplace the division at Romax = 2.0 %; hence, semifusinite is somewhat vaguely defined as “fusinite with low reflectance.”3.4.17 sporinite, na liptinite maceral exhibiting various lenticular, oval, or round forms that reflect the cro
38、ss-sectioning of aflattened, hollow, ovoid body; sometimes exhibits rod-like projections that are small relative to the size of the total body.3.4.17.1 DiscussionSporinite originated as a lipid substance that covered, as a skin, ovoid spore or pollen grains which commonly ranged from aroundten to se
39、veral hundred micrometres in diameter. Sporinite often occurs as fragments derived from these initially ovoid bodies.3.4.18 vitrinite, nthe predominant maceral in most coals of intermediate reflectance occurring as substantial volumes of moreor less uniformly reflecting material or as a matrix enclo
40、sing particles of other macerals and mineral matter or as particles or bandsintermixed with other maceral fragments.3.4.18.1 DiscussionBecause most vitrinite is derived from the cellular, structural tissues of plants, it may exhibit relict cell structure. The reflectanceD2799 123of vitrinite is rela
41、ted to the rank of the coal in which it is found. Reflectance increases (from around Romax = 0.3 % in ligniticcoals) in parallel with the increase in fixed carbon yield associated with increasing rank. Because many of the properties of typicalcoals reflect the properties of the dominating vitrinite,
42、 it is common practice to estimate coal properties and process behaviors bymeasuring the reflectance of a representative sampling of vitrinite in the specimen according to procedures described in TestMethod D2798.Pseudovitrinite, a certain variety of vitrinite, is differentiated by some practitioner
43、s. It exhibits slightly higher reflectance thanmost of the vitrinite in the coal and is commonly slitted, with indistinct remnant cell structure and angular or jagged edges.Pseudovitrinite has been postulated to be less thermoplastic in the coking process.The term vitrinite is currently used as both
44、 a maceral and maceral group.4. Summary of Test Method4.1 The components in a representative crushed coal sample, prepared as prescribed in Practice D2797, are identified under amicroscope according to their reflectance, other optical properties, and morphology. The proportions of these components i
45、n asample are determined by observing a statistically adequate number of points, and summing those representative of eachcomponent. Only area proportions of components are determined on a surface section of a sample. However, the area and volumeproportions are the same when the components are random
46、ly distributed throughout the sample.4.1.1 Color photomicrographs of the maceral components of bituminous coals are available from various publications andwebsites.45. Significance and Use5.1 The volume percent of physical components of coal is used as an aid in coal seam correlation and in the char
47、acterizationof coals for their use in carbonization, gasification, liquefaction, and combustion processes.5.2 This test method is for use in scientific and industrial research, not compliance or referee tests.6. Apparatus6.1 MicroscopeAny microscope with a mechanical stage and a vertical illuminator
48、 (that is, metallurgical or opaque-oremicroscope) may be used, provided that the lens combination of objective and eyepiece permits resolution of objects on the orderof 1 to 2 m. A minimum magnification of approximately 400 diameters is recommended. Either a prism or a partially reflectingglass plat
49、e may be used in the illuminator. One eyepiece of the microscope should be fitted with a graticule or crosshair.6.1.1 Eyepiece DiskIf other than crosshairs are used, the eyepiece disk shall contain a Whipple graticule or one of such designthat four points are visible, lying at the corners of a square covering nearly all of the field of view. The minimum effective distancebetween the points, referred to the plane of the specimen, shall be 0.1 mm.6.1.2 Mechanical StageThe mechanical stage shall be of such type that the specimen can be
