1、Designation: D 5061 07Standard Test Method forMicroscopical Determination of the Textural Components ofMetallurgical Coke1This standard is issued under the fixed designation D 5061; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t
2、he year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the equipment and proceduresused for determining the types and amounts of coke car
3、bonforms and associated recognizable coal- and process-derivedtextural components in metallurgical coke in terms of volumepercent. This test method does not include coke structuralcomponents such as coke pores, coke wall dimensions, or otherstructural associations.1.2 This standard does not purport
4、to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 121 T
5、erminology of Coal and CokeD 3997 Practice for Preparing Coke Samples for Micro-scopical Analysis by Reflected Light3. Terminology3.1 DefinitionsFor additional definitions of terms used inthis test method, refer to Terminology D 121.3.2 Definitions of Terms Specific to This Standard:3.2.1 anisotropi
6、c, adjexhibiting optical properties of dif-ferent values when viewed with an optical microscope havingmutually exclusive polarized light, for example, crossed nicols.3.2.2 binder phase, na continuous solid carbon matrixformed during the thermoplastic deformation of those coalmacerals that become pla
7、stic during carbonization.3.2.2.1 DiscussionThe binder phase material is formedfrom the thermoplastic deformation of reactive (vitrinite andliptinite) and semi-inert (semifusinite) coal macerals of metal-lurgical bituminous coals. During thermoplasticity, the inertcoal maceral and mineral are partly
8、 or wholly incorporated intothe binder phase.Also, most of the coke pores are located in thebinder phase.3.2.3 carbon form, nmicroscopically distinguishable car-bonaceous textural components of coke, but excluding mineralcarbonates.3.2.3.1 DiscussionCarbon forms are recognized on thebasis of their r
9、eflectance, anisotropy, and morphology. They arederived from the organic portion of coal and can be anisotropicor isotropic.3.2.4 circular anisotropic phase, na group of binder-phase anisotropic carbon textures that are distinguished byapproximately circular domains (that is length equals width)and
10、composed of fine circular (0.5 to 1.0-m), medium circular(1.0 to 1.5-m), and coarse circular (1.5 to 2.0-m) sizecategories.3.2.5 coke pore, na microscopically distinguishable voidthat is a structural element of coke.3.2.5.1 DiscussionCoke pores are considered to be nearlyspherical-shaped voids creat
11、ed by the entrapment of gaseousvolatiles during the solidification of thermoplastic coal. How-ever, other types of voids can be distinguished in coke thatinclude fractures or cracks, interconnected and elongatedpores, and the open cell lumens of fusinite and semifusinite.The size and shape of the vo
12、ids are coal rank and grade, and tosome degree, process dependent. Pore sizes vary from tens ofangstroms to tens of millimetres in any given coke.3.2.6 coke reactivity, na measure of the mass loss whencoke, held at a designated temperature, is contacted withgaseous carbon dioxide over a specific tim
13、e interval.3.2.7 coke wall, na predominantly carbonaceous layerthat encloses a coke pore and which is a structural element andessence of coke.3.2.8 depositional carbon, na group of carbon forms thatare formed from cracking and nucleation of gas-phase hydro-carbon molecules during coal carbonization.
14、1This test method is under the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct responsibility of Subcommittee D05.28 on PetrographicAnalysis of Coal and Coke.Current edition approved Oct. 1, 2007. Published Ocotber 2007. Originallyapproved in 1992. Last previous edition approved
15、 in 2005 as D 5061 - 05.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Ba
16、rr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.8.1 pyrolytic carbon, nan anisotropic carbon form thatis formed by the deposition of carbon parallel to an inertsubstrate causing the resulting texture to appear ribbon-like.3.2.8.2 sooty carbon, nan isotropic carbon f
17、orm com-prised of approximately spherical particles of less than 1-mdiameter sometimes referred to as combustion black.3.2.8.3 spherulitic carbon, na spherical anisotropic car-bon form sometimes referred to as thermal black that is formedby the deposition of carbon concentrically around a nucleus.3.
18、2.9 domain, na region of anisotropy in a carbon formthat is distinctively marked by its isochromatic boundary andcleavage.3.2.10 filler phase, na discontinuous solid formed fromcoal macerals and minerals that do not deform thermoplasti-cally during carbonization.3.2.10.1 DiscussionThe filler phase m
19、aterial is formedfrom coal macerals that are inert with respect to developmentof thermoplasticity (inertinite), the inorganic components ofcoal (minerals), as well as normally reactive coal entities thatare noncoking or have been rendered inert by thermal oxida-tion, natural weathering or brecciatio
20、n. These inert materialspossess their original morphologies, but their reflectance andchemical properties have been altered prior to or duringcarbonization.3.2.11 green coke, ncarbonaceous binder or filler phasematerial that has exceeded the temperature of thermoplasticity,but has not obtained the t
21、emperature of metallurgical coke.3.2.11.1 DiscussionGreen coke is recognized on the basisof relative reflectance in comparison to fully carbonized coke.Green coke exhibits varying degrees of lower reflectance thanfully carbonized coke.3.2.12 incipient anisotropic phase, na binder-phase car-bon textu
22、re having a domain size (less than 0.5 m) that is nearthe measuring resolution of the light microscope.3.2.13 isotropic phase, na binder-phase carbon texturethat exhibits optical properties that are the same in all direc-tions when viewed with an optical microscope having mutuallyexclusive polarized
23、 light, for example, crossed nicols.3.2.14 lenticular anisotropic phase, na group of binder-phase anisotropic carbon textures distinguished by their lens-shaped domains (that is, length (L) to width (W) ratio of 2W 4W), and subdivided based on domain width as fine ribbon(2.0 to 12.0-m), medium ribbo
24、n (12.0 to 25.0-m), and coarseribbon (25.0-m) size categories.3.2.16 textural component, nthe collective term used todescribe carbon forms and recognizable coal- and process-derived components (binder-phase, filler-phase, and miscella-neous material) in coke.3.2.17 vitrinite type, nreflectance class
25、es of vitrinitewhich span 0.1 % reflectance intervals.3.2.17.1 DiscussionThis term is commonly referred to asV-Type. For example, V-type 6 includes vitrinite reflectancevalues from 0.6 through 0.69 %.4. Summary of Test Method4.1 The textural components of coke (coke carbon formsand associated coal-
26、and process-related components) in arepresentative crushed particulate coke sample, prepared in theform of a briquetted, polished specimen as described inPractice D 3997, are identified under a microscope accordingto their degree of anisotropism, carbon form domain sizes,boundary size, color of indi
27、vidual isochromatic domains, theirmorphology, relative reflectance, and other optical properties.The proportions of these textural components in a sample aredetermined by observing a statistically adequate number ofpoints, and summing those representative of each component.Only area proportions of c
28、omponents are observed on thebriquette surface. However, the area and volume proportionsare the same when the components are randomly distributedthroughout the sample.4.1.1 Color photomicrographs of the textural components ofmetallurgical coke illustrating their microscopic features areavailable fro
29、m various publications and websites.3,45. Significance and Use5.1 The determination of the volume percent of the texturalcomponents in coke is useful to characterize the opticalproperties of coke as it relates to utilization. Specifically, thetechnique has been used as an aid in determining coal ble
30、ndproportions (after correcting for coke yield), and recognition offeatures present in the coke that can be responsible for cokequality or production problems such as reduced coke strengthor difficulty in removing coke from commercial coke ovens, orboth. The study of coke textures is also useful in
31、promoting abetter understanding of coke reactivity, and the relationshipbetween coal petrography and its conversion to coke.45.2 This test method is used in scientific and industrialresearch, but not for compliance or referee tests.6. Apparatus6.1 MicroscopeA high quality reflected-light microscopew
32、ith a vertical illuminator and rotating mechanical stage isused, provided that the objective and eyepiece lenses permitresolution of objects on the order of 0.5 m. The objective lensshall be of such construction that samples can be studied in oilwith plane-polarized light. A minimum total magnificat
33、ion ofapproximately 500 diameters is recommended. Use of anaccessory plate (quartz, gypsum, or mica), an analyzer, andpolarizer combination is recommended to achieve optimumoptical effect for discriminating among the various texturalcomponents. Either a prism or a partially reflecting glass platemay
34、 be employed in the illuminator. One eyepiece of themicroscope must be fitted with a special ruled graticule disc.3Crelling, J.C., Petrographic Atlas of Coals, Cokes, Char, Carbons, andGraphites available from http:/mccoy.lib.siu.edu/projects/crelling2/atlas/.4Gray, R. J., and DeVanney, K. F., “Coke
35、 Carbon Forms: MicroscopicClassification And Industrial Applications,” International Journal of Coal Geology,Vol 6, 1986, pp. 277297.D50610726.1.1 Eyepiece DiscThe eyepiece shall contain a ruledgraticule disc to enable size estimations and to provide afield-of-view grid for point counting. The desig
36、n may be asquared pattern (10 by 10 squares) containing a boldercrosshair with one of the squares near the center crosshairintersection divided into 25 subsquares. The ruled portion ofthe disc shall cover at least one third of the field of view.6.1.2 Mechanical StageThe mechanical stage shall be ofs
37、uch type that the specimen can be quickly advanced bydefinite fixed increments in two perpendicular directions (re-ferred to as the X and Y directions).6.2 CounterThe counter shall be capable of recordingcounts for at least eight components (preferably twelve ormore) equipped with a totalizer. The c
38、ounter design can eitherbe mechanical or electrical.6.3 Immersion OilThe oil shall be a nondrying, noncor-rosive, noncarcinogenic type having similar properties as usedfor coal microscopic techniques.7. Organization of Analysis47.1 Textural components are grouped into three majorcategories; (1) bind
39、er phase carbon forms, (2) filler phasecarbon forms (including coal-related inorganic material), and(3) miscellaneous materials. These categories are shown insummary form in Table 1. Volume percent of the various typesof binder phase carbon forms should be determined during thefirst microscopic anal
40、yses. The volume percent of the fillerphase (including coal-related inorganic material) should bedetermined as a second analysis. The miscellaneous materialsare commonly determined during analysis of the filler phase.7.1.1 Binder Phase Carbon Form DeterminationsThecomponents counted and kept separat
41、e shall be the following:isotropic, incipient, circular anisotropic (fine), circular aniso-tropic (medium), circular anisotropic (coarse), lenticular aniso-tropic (fine), lenticular anisotropic (medium), lenticular aniso-tropic (coarse), ribbon anisotropic (fine), ribbon anisotropic(medium), ribbon
42、anisotropic (coarse). These binder phasecategories relate to parent coal rank. When other components(filler phase, including coal-related inorganic material, andmiscellaneous materials) are encountered, they are to beallocated to the appropriate binder phase category within whichthey are incorporate
43、d.7.1.2 Filler Phase Carbon Form Determinations (IncludingCoal-Related Inorganic Material)The components countedand kept separate shall be the following: one category for allbinder phase carbons (no discrimination to specific binderphase components is necessary), organic inerts (fine), organicinerts
44、 (coarse), inorganic inerts (fine), inorganic inerts (coarse),miscellaneous inerts (by type, such as noncoking vitrinite,coked oxidized coal, coked brecciated coal, etc.), and others.Filler phase materials relate back to the parent coal type.7.1.3 Miscellaneous Materials DeterminationThe com-ponents
45、 counted and kept separate shall be the following:depositional carbons (by type, that is, sooty, spherulitic, orpyrolytic) and any other observations such as additives (breeze,anthracite, petroleum coke, etc.), coal, and green coke (byrelative degree). Due to the normally small occurrences orabsence
46、 of these components, they are commonly countedduring the filler phase counting procedure described in 7.1.2.These miscellaneous materials generally relate to coke plantprocesses and operational practices not directly related toparent coal rank or type.NOTE 1The degree of detail necessary will dicta
47、te the specificcomponents quantified. The specified components to be counted in thistest method assume that the operator is generating a detailed analysis. Itmay be practical to lump some components together. This is up to thediscretion of the operator or based on agreement between such partiesinvol
48、ved.8. Procedure8.1 Mount the coke briquette on a glass slide containingmodeling clay, level using a specimen leveling press, and placeon the stage of the microscope. Use a few drops of immersionoil on the briquette surface.8.2 Adjust the microscope polarizer and analyzer to acrossed polarized posit
49、ion. Mount the accessory plate betweenthe polarizer and the analyzer to the position that yields optimalretardation and color enhancement.8.3 Binder Phase CountingPosition the coke briquette bymeans of the mechanical stage to the starting position. Identifyfour points per field under the special graticule or whipple disc(the intersection at each of the outermost corners). The exactdirections traversed on the briquette are up to the preference ofthe operator. An example of one type of surface traverse is tomove the mechanical stage 1 mm to t
