1、Designation: D3997/D3997M 97 (Reapproved 2009)Standard Practice forPreparing Coke Samples for Microscopical Analysis byReflected Light1This standard is issued under the fixed designation D3997/D3997M; the number immediately following the designation indicates theyear of original adoption or, in the
2、case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers laboratory procedures for thepreparation of granular samples of cok
3、e for examination witha reflected light microscope. The samples prepared are used foridentifying and quantifying the textural components in coke.This practice does not apply to the preparation of oriented lumpspecimens of coke for structural analysis.1.2 The values stated in either SI units or inch-
4、pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.3 This standard does not purport t
5、o 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:2D121 Ter
6、minology of Coal and CokeD346 Practice for Collection and Preparation of CokeSamples for Laboratory AnalysisD5061 Test Method for Microscopical Determination of theTextural Components of Metallurgical CokeE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3. Terminology3.1 DefinitionsFo
7、r additional definitions of terms used inthis practice, refer to Terminology D121.3.1.1 briquette, na cylindrical block composed of granu-lated coal or coke particles compressed and embedded with anepoxy binder.4. Summary of Practice4.1 Arepresentative sample is crushed to a specified particlesize,
8、oven-dried, mixed with a binder, and formed into a blockspecimen referred to as a briquette. The briquette is thenpolished to a flat, scratch-free surface for microscopical ex-amination under reflected light.5. Significance and Use5.1 Briquettes of granular coke prepared in accordance withthe labora
9、tory procedures of this practice will have flat,scratch-free surfaces suitable for examination with a micro-scope using reflected light illumination. The polished surfaceof briquettes prepared using this practice will contain particlesrepresentative of the original gross sample.5.2 Samples prepared
10、by this practice are used for micro-scopical determination of the textural components in coke (seeTest Method D5061).6. Apparatus6.1 Grinder, Pulverizer, Mill, or Jaw Crusher, or othersuitable equipment for final crushing of the sample to pass a2.36-mm (No. 8) sieve.6.2 Coarse Riffle Sampler, with a
11、t least twelve divisions ofnot less than 12.7 mm 12 in. and not greater than 19.1 mm 34in.6.3 Medium Riffle Sampler, with at least twelve divisions ofnot less than 6.4 mm 14 in. and not greater than 12.7 mm 12in.6.4 SievesA 6.4-mm 14-in. and 2.36-mm (No. 8) U.S.A.Standard Sieve (see Specification E1
12、1).6.5 MoldsContainers to hold the coke/binder mixturewhile the binder hardens. Generally, steel cylindrical molds areused (see Fig. 1). However, it is acceptable to use other moldmaterials that successfully yield the same type of briquette.6.5.1 The mold shall be made of separable parts or someothe
13、r design so that the briquette can be ejected after thebriquette has hardened.1This practice is under the jurisdiction of ASTM Committee D05 on Coal andCoke and is the direct responsibility of Subcommittee D05.28 on PetrographicAnalysis of Coal and Coke.Current edition approved Sept. 1, 2009. Publis
14、hed March 2010. Originallyapproved in 1992. Last previous edition approved in 2004 as D3997 97(2004).DOI: 10.1520/D3997_D3997M-97R09.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume infor
15、mation, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.5.2 The mold shall be large enough to provide a plane areaof4cm2or more on one side of the briquette. (Designs
16、ofsuitable 25- and 32-mm 1- and 114-in. inside-diameter moldsare shown in Fig. 1).6.6 Hydraulic Press, capable of producing a pressure up to28 MPa 4000 psi on the briquette with an attachment to ejectthe briquette after hardening of the binder.6.7 Grinding and Polishing Equipment, having one orsever
17、al laps on which the coke briquette can be ground andpolished to a flat, scratch-free surface. Laps may be made ofiron, brass, or bronze.NOTE 1Equipment that has 203- or 305-mm 8- or 12-in. diameterdisk laps, gear-driven at 160 to 170 r/min, and has an automatic sampleholder attachment is recommende
18、d.6.8 Sample Cleaner, essential for cleaning coke briquettesbetween the different grinding or polishing stages. This may bea simple stream of water or an airjet, but an ultrasonic cleaneris recommended.6.9 ContainersIf samples are to be transported or storedbefore briquettes are prepared, glass jars
19、, bottles, or metal canshaving tight-fitting closures shall be used. Metal cans shallhave plastic liners.7. Materials7.1 BinderAny binding material, such as epoxy resin,fulfilling the following requirements may be used for preparingthe coke briquette:7.1.1 The binder shall hold all coke particles se
20、curelyduring grinding, polishing, and observation.7.1.2 The binder shall not react with the coke or theatmosphere.7.1.3 Under the microscope, the binder shall contrast mark-edly with the coke being observed when immersed in oil.7.1.4 The binder shall be such that a substantially flat andscratch-free
21、 surface can be obtained as a result of the grindingand polishing procedure.NOTE 2Relief, or difference in level, particularly between the cokeand the binder, is undesirable for microscopic observation. Relief dependsa great deal on the polishing technique.7.2 Release AgentAny preparation that does
22、not damagethe molds or adversely affect the coke or mounting mediummay be used to coat the inside of the mold and facilitateejection of the briquette.7.3 Grinding AbrasivesWater-resistant, adhesive-backedsilicon carbide papers of grit Nos. 120, 240, 400, and 600. Thegrinding and polishing sequences
23、recommended are listed inTable 1.NOTE 3It is acceptable to use commercially available diamondimpregnated wheels as substitutes particularly for the coarse grindingabrasive papers if the same polish quality requirements are met asspecified in Section 10.7.4 Polishing AbrasivesAluminum oxide slurries
24、in 0.3-and 0.05-m sizes. The grinding and polishing sequencesrecommended are listed in Table 1.NOTE 4It is acceptable to use commercially available colloidal silicaas a substitute for aluminum oxide if the same polish quality requirementsare met as specified in Section 10.7.5 Lap CoveringsNap-free c
25、loths or chemotextile mate-rial backed with water-resistant adhesive.7.6 DetergentAny nonoxidizing detergent may be usedfor cleaning briquettes after each grinding or polishing stage.8. Sampling8.1 Obtain gross samples of coke in accordance with TestMethod D346, when appropriate.8.2 If the coke appe
26、ars wet, oven-dry the coke until nosurface moisture is evident.8.3 Crush and divide the gross sample in accordance withTest Method D346 to obtain a subsample of 500 gof 2.36-mm (No. 8) sieve size. Particle size reduction is donein such a manner that the production of fines is minimized.8.4 Pass the
27、dried, sieved coke through the medium rifflesampler (see 6.3) to obtain a sample of about 50 g for a set oftwo briquettes about 25 mm 1 in. in diameter.NOTE 1Material: cold rolled or stainless steel. Dimensions a and b(inside diameters) are nominally 32 and 25 mm. If an automatic polishingattachment
28、 is to be used, these dimensions should be specified to yield abriquette fitting snugly in the briquette holder.FIG. 1 Molds Suitable for Briquetting Coke SamplesTABLE 1 Suggested Abrasive Sequences for Grinding andPolishing Coke BriquettesANOTE 1Alternative abrasives and techniques are permissible
29、if thesame polish quality requirements are met as specified in Section 10.Sequence Igrinding with silicon carbide paper:1. No. 120 grit paper2. No. 240 grit paper3. No. 400 grit paper4. No. 600 grit paperSequence IIpolishing with alumina on cloths:1. 0.3-m slurry on chemotextile2. 0.05-m slurry on c
30、hemotextileD3997/D3997M 97 (2009)28.5 A reserve coke sample should be stored as described in6.9.9. Preparation of Coke Briquettes9.1 Prepare a coke briquette using a binder that meets therequirements of 7.1 in such a manner that, when polished, atleast 60 % of the cross-sectional area will be coke.
31、A suitableprocedure for use with epoxy resin is as follows:9.1.1 Add activator or hardener, in the amount recom-mended by the supplier, to about4gofepoxy resin for each 10g of coke. Mix thoroughly with a spatula or disposable woodenstirring stick. Place the riffled coke sample in a suitable smalldis
32、posable container. Thoroughly stir a few drops of resin intothe coke sample. Continue to add resin, a few drops at a time,and stir until all coke particles are wetted and the coke-resinmixture coheres when pressed to the side of the container withthe spatula.9.1.2 Coat the internal surfaces of a mol
33、d (including plung-ers if applicable) with a release agent and insert the lowerplunger. Fill the mold with the coke-resin mixture. Insert theupper plunger, place the mold in the hydraulic press, and applypressure on the briquette for 3 to 5 s. Pressures of less than 28MPa 4000 psi have been found to
34、 be adequate. Release andreapply the pressure; repeat this cycle three times to expel airbubbles.9.1.3 Allow the briquette(s) to harden overnight at roomtemperature or apply heat to harden as recommended by themanufacturer of the epoxy.9.1.4 Eject the coke briquette from the mold using thespecial at
35、tachment on the press and label the briquette.NOTE 5It is acceptable to use 32- or 38-mm 114-or112-in.preformed one-piece molds that do not include separable parts and do notrequire pressure during the coke-briquetting procedure. This type ofbriquette is commonly referred to as a loose mount. It is
36、also acceptableto use other types of binding material other than the commonly usedactivator/resin-based epoxy. Binding powders used in the proper ratio ofcoke to binder with proper heat treatment have also been found accept-able.10. Preparation of Briquette Surface10.1 Grind and polish one of the fl
37、at surfaces of thebriquette on a lap to obtain a surface suitable for microscopicalexamination. Grinding and polishing can be done either byhand manipulation or with an automatic attachment. Use aseries of abrasives of decreasing particle size according to aplan such as the one described in Table 1.
38、 The surface soobtained shall meet the following requirements:10.1.1 Enough material shall be removed from the briquetteto produce a flat surface over the entire area.10.1.2 The surface shall be free of pits caused by loss ofgrains of coke or mineral matter.10.1.3 The surface shall be reasonably fre
39、e of scratcheswhen examined at a magnification of 3500 or more under oilimmersion.10.1.4 The surface shall be reasonably free of relief.10.1.5 The surface shall be free of grinding and polishingcompounds.10.2 After each grinding or polishing step, clean the bri-quette(s) to remove all abrasive and d
40、islodged coke andmineral cuttings. Use of an ultrasonic cleaner filled with waterand detergent is recommended.11. Keywords11.1 briquettes; coke; microscopyASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard.
41、 Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed e
42、very five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible tec
43、hnical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoho
44、cken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D3997/D3997M 97 (2009)3
