1、Designation: C561 91 (Reapproved 2010)1An American National StandardStandard Test Method forAsh in a Graphite Sample1This standard is issued under the fixed designation C561; 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.This standard has been approved for use by agencies of the Department of Defense.1NOTEUpdated units of measure throughout the
3、standard editorially in May 2010.1. Scope1.1 This test method provides a practical determination forthe ash content in a graphite sample.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to a
4、ddress 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:2C562 Test M
5、ethod for Moisture in a Graphite Sample3. Significance and Use3.1 This test method provides a practical estimate of non-burnable residues in commercially available graphite materials.The ash values determined by this test method are of use incomparing the relative purity of various grades of graphit
6、e. Tofacilitate use, this test method institutes simplifications thatpreclude the ability to determine absolutely the ash values ofthe test graphite material due to uncontrolled sources of tracecontamination.3.2 This test method is not intended for use in determiningthe ash content of purified graph
7、ites, for example, nuclearmaterials. The relationship between the mineral content of agraphite sample and the ash content of that sample is unknownand is not determined by the application of this test method.4. Interferences4.1 Although permitted within the scope of this test method,the use of alumi
8、na ceramic crucibles may affect results due todifficulties in obtaining repeatable or proper weights, or both,because of (1) the hygroscopic nature of some ceramiccrucibles, and (2) the possible chemical combination of traceelements with the ceramic crucible.4.2 Any ash or trace elements introduced
9、to the sample willinfluence results. Contamination can occur during drilling toobtain the sample and during pulverization. (See 6.1.)5. Apparatus5.1 Alumina Ceramic or Platinum Crucible or Dish, suit-able for holding sample (subsequently called sample holder).5.2 Analytical Balance, capable of weigh
10、ing to 60.0002 g.5.3 Muffle Furnace, capable of reaching 950C with con-troller capable of maintaining a temperature of 950 6 20C.5.4 Platinum or Stainless Steel Wire.5.5 Desiccator, charged with indicating desiccant.5.6 Drying Oven, air convection type, capable of beingcontrolled to 110 6 2C.6. Samp
11、ling6.1 Samples may be solid or particulate. Solid bodies maybe sampled by removing one or more solid pieces from thebody by, for example, sawing, turning, milling, or fracturing.Particulate samples may be generated from solid bodies bydrilling, using a carbide drill to minimize contamination, or by
12、other crushing and grinding methods.7. Procedure7.1 Dry the sample in accordance with Test Method C562,or for a minimum of 16 h in a drying oven at 110 6 2C, andallow the sample to cool to room temperature in the desiccator.7.2 Tare a dried sample holder using an analytical balance to60.002 g. As so
13、on as the sample has cooled to roomtemperature, remove it from the desiccator and weigh a 25- to50-g sample into the tared sample holder. Reweigh the sampleand sample holder to 60.002 g.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the d
14、irect responsibility of SubcommitteeD02.F0 on Manufactured Carbon and Graphite Products.Current edition approved May 1, 2010. Published May 2010. Originallyapproved in 1965. Last previous edition approved in 2005 as C56191(2005). DOI:10.1520/C0561-91R10E01.2For referenced ASTM standards, visit the A
15、STM 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 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Uni
16、ted States.7.3 Introduce a slow stream of air into the muffle furnace(Note 1). Place the sample holder containing the sample intothe furnace, then heat the furnace so that the sample reaches500C in 1 h and 750C in 2 h.NOTE 1The stream of air into the furnace should be carefully adjustedso that the s
17、ample or ash will not be blown from the dish. The air streammay be admitted by leaving the door of the furnace open a slight amount.Exercise care when placing a sample into a warm furnace so that nosample material will be lost due to drafts.7.4 To aid in oxidation, stir the sample periodically with
18、thewire. The absence of black flecks indicates that ashing iscomplete; at that time raise the furnace temperature to 950Cfor1h.7.5 Remove the dish containing the ash from the furnace,(see Note 1) and cool to room temperature in the desiccator.Following removal from the desiccator, weigh the dish wit
19、h theash as rapidly as possible.7.6 Replace the sample in the furnace at 950C for 30 minand repeat the procedure prescribed in 7.5 until a constantweight is obtained to 60.002 g.8. Calculation8.1 Calculate the percentage of ash as follows:Ash, % 5 C 2 A!/B 2 A!# 3 100 (1)where:A = weight of the samp
20、le holder,B = weight of the sample holder and dried sample,C = weight of the sample holder and ash.9. Report9.1 The report shall include the following:9.1.1 Proper identification of the sample, and9.1.2 Results obtained from at least two ash determinationsand their averages.10. Precision and Bias310
21、.1 The precision of this test method was determinedduring a round-robin test among four laboratories testingsamples split from a common sample which was ground to passa No. 60 (250-m) sieve. This sampling method was used forthe round-robin to minimize variations among samples pro-vided to participat
22、ing laboratories.10.2 On this sample the mean, standard deviation betweenlaboratories and standard deviation within laboratories were,respectively:Mean 0.7286%Between laboratories 0.0159%Within laboratories 0.0127%10.3 No bias was noted during this round-robin test; how-ever, the method is empirical
23、 and there is no suitable referencematerial that can be used to determine the bias of this testmethod.11. Keywords11.1 ash; carbon; graphiteASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this
24、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 every five years
25、 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 technical committe
26、e, 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 Conshohocken, PA 19428-
27、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/).3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:C05-1008.C561 91 (2010)12
