1、Designation:D279910 Designation: D2799 11Standard 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 revisio
2、n, the year 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
3、 coal sample 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 ca
4、se (the SI unit 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 applicabil
5、ity of regulatorylimitations 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 Tes
6、t Method for Ash in the Analysis Sample of Coal and Coke from CoalD3177 Test Methods for Total Sulfur in the Analysis Sample of Coal and CokeE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a
7、 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) alginitecutiniteresin
8、itesporiniteInertinite fusiniteinertodetrinitemacrinitemicrinitefunginitesecretinitesemifusinite3.3 Many laboratories associated with the coke-making industry use the following simplified classification for petrographicanalysis of bituminous coal:1This test method is under the jurisdiction of ASTM C
9、ommittee D05 on Coal and Coke and is the direct responsibility of Subcommittee D05.28 on Petrographic Analysisof Coal and Coke.Current edition approved Sept.April 1, 2010.2011. Published September 2010.April 2011. Originally approved in 1969. Last previous edition approved in 20092010 asD2799 109. D
10、OI: 10.1520/D2799-101.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.1This document is not an ASTM standar
11、d and is intended only to provide the user 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 o
12、nly the current versionof the standard 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 States.vitriniteliptinite (other than resinite)resinitesemifusinitemicrinitefusinitemineral
13、 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 somewhatirregular reflectance and sometimes occurring in clusters reflecting an origin from Botryococcus algae.3.4.1.1 Discus
14、sionAlginite 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 twig-covering plant cuticle,frequently exhibiting reticulation in planar section and a serrated edge in cross se
15、ction.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 ovoid bodies, frequently containing voids, reflecting an originfrom fungal sclerotia; also occurs (especially in
16、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 plant cell wallstructure, and with a particle size greater than 50 m except when it occurs as a fragment within
17、 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 than anthracitic, inertinite reflectance commonly spans the range from onlyslightly higher than associated vitrini
18、te to very high reflectance (often as high as Romax $6 %). In anthracitic rank coals, inertinitereflectance may be lower than that of vitrinite, and is then recognized by its morphology and form of anisotropy. Highly reflectinginertinite commonly exhibits relief on polished surface. Its name derives
19、 from the fact that most varieties behave inertly in thethermoplastic deformation during the coking process (except in its lowest reflecting manifestation). The volatile matter yield ofinertinite is lower than that of other macerals in the same coal.3.4.7 inertodetrinite, nan inertinite maceral occu
20、rring 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, nmacerals that exhibit lower reflectance than other organic substances in a coal, appearing black to dark grayand th
21、at 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 similar sized, low reflectance,nonfluorescing clay minerals. Liptinite is derived principally from lipid substance
22、s forming skins (exines) and resinous secretionsor exudates of plants. Liptinite is sub-classified on the basis of morphology inherited from plant structure. In coals in whichvitrinite reflectance exceeds about 1.4 %, liptinite can be indistinguishable from vitrinite. Liptinite has the highest volat
23、ile matteryield 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 microscopic properties.3.4.9.1 DiscussionMacerals originate from plant tissues, secretions, and exudates that have been
24、altered by geologicalprocesses and may contain up to several weight percent of inorganic elements in microscopically indistinguishable form.3.4.10 maceral classification, nThe systematic division of the organic substances (macerals) in coal based on their appearancein the optical microscopic.3.4.10.
25、1 DiscussionAlthough macerals may be identified in translucent, thin sections using criteria not defined herein, this testmethod deals only with identification and classification based on microscopic appearance on polished surfaces according toPractice D2797. Three major maceral groups are recognize
26、d on the basis of relative reflectance in white light, specifically:vitrinitemoderately reflecting (intermediate gray), liptinitepoorly reflecting (black to dark gray), and inertinitehighlyreflecting (light gray to white). Each group can be subdivided on the basis of other microscopically distinctiv
27、e features such as:reflectance contrasts (relative shades of gray); morphology, that is, shape and size (morphologic distinctions in definitionscontained herein are idealized because morphologic appearance depends on the initial form of the source material, its state ofpreservation, including granul
28、ation, and on the orientation of the cross section presented on the polished preparation); spatialassociation with other substances; fluorescence properties (color, intensity) in blue to ultraviolet light; relief; color tinges; internalreflections; and anisotropic properties.Microscopic criteria pro
29、vide classification capability without any implication of absolute chemical composition or physicalbehavior, although some properties relative to other macerals in the same coal can be inferred broadly. Substances classified as thesame maceral by microscopic criteria can differ chemically, physicall
30、y, 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 most practitioners of this test method.3.4.11 macrinite, nan inertinite maceral, generally nonangular, exhibiting no reli
31、ct 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 10D2799 112m and most commonly occurring as particles around 1- to 5-m diameter.3.4.13 mineral matter, nin coal, historically
32、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, nitrogen, and sulfurin the organic fraction.3.4.14 resinite, na liptinite maceral occurring as rounded, ovoid, o
33、r 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 oblong bodies, without obvious plant structure,vesicled to non-vesicled, sometimes containing characteristic fract
34、ures, slits, or a notch.3.4.15.1 DiscussionSecretinite is considered to be derived by the oxidation of plant resin secretions or humic gels. Vesicularand non-vesicular secretinite was formerly included in sclerotinite of fungal origin. Secretinite is a common maceral in medium-and high-rank Permian
35、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 from slightly greater than that of associated vitrinite to some value intermediate to that ofthe brightest fusini
36、te. 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 fusinite has not been universally defined,although some practitioners place the division at Romax = 2.0 %; hence,
37、semifusinite is somewhat vaguely defined as “fusinite withlow reflectance.”3.4.17 sporinite, na liptinite maceral exhibiting various lenticular, oval, or round forms that reflect the cross-sectioning of aflattened, hollow, ovoid body; sometimes exhibits rod-like projections that are small relative t
38、o 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 whichcommonly ranged from around ten to several hundred micrometres in diameter. Sporinite often occurs as fragments derived fromthese initially ovoid bodie
39、s.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 enclosing particles of other macerals and mineral matter or as particles or bandsintermixed with other maceral fragments
40、.3.4.18.1 DiscussionBecause most vitrinite is derived from the cellular, structural tissues of plants, it may exhibit relict cellstructure. The reflectance of vitrinite is related to the rank of the coal in which it is found. Reflectance increases (from aroundRomax = 0.3 % in lignitic coals) in para
41、llel with the increase in fixed carbon yield associated with increasing rank. Because manyof the properties of typical coals reflect the properties of the dominating vitrinite, it is common practice to estimate coal propertiesand process behaviors by measuring the reflectance of a representative sam
42、pling of vitrinite in the specimen according toprocedures described in Test Method D2798.Pseudovitrinite, a certain variety of vitrinite, is differentiated by some practitioners. It exhibits slightly higher reflectance thanmost of the vitrinite in the coal and is commonly slitted, with indistinct re
43、mnant 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 a maceral and maceral group.4. Summary of Test Method4.1 The components in a representative crushed coal sample, prepared a
44、s prescribed in Practice D2797, are identified under amicroscope according to their reflectance, other optical properties, and morphology. The proportions of these components in asample are determined by observing a statistically adequate number of points, and summing those representative of eachcom
45、ponent. 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 randomly distributed throughout the sample.4.1.1 Color photomicrographs of the maceral components of bituminous coals are availabl
46、e from various publications andwebsites.35. Significance and Use5.1 The volume percent of physical components of coal is used as an aid in coal seam correlation and in the characterizationof coals for their use in carbonization, gasification, liquefaction, and combustion processes.5.2 This test meth
47、od 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 (that is, metallurgical or opaque-oremicroscope) may be used, provided that the lens combination of objective and eyepiece
48、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 plate may be used in the illuminator. One eyepiece of the microscope should be fitted with a graticule or crosshair.6.1.1 Eyepie
49、ce 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 distance3U.S. Geological Survey, ASTM International Maceral Composition of Coals available from: http:/energy.er.usgs.gov/coal_studies/organic_petrology/photo_atlas.html.D2799 113between the points, referred to the plane of the specimen, shall be 0.1 mm.6.1.2 Mechanical StageThe mechanical stage sha
