ASTM D4715-1998(2017) Standard Test Method for Coking Value of Tar and Pitch (Alcan)《测定焦油和硬沥青(Alcan)焦化值的标准试验方法》.pdf

1、Designation: D4715 98 (Reapproved 2017)Standard Test Method forCoking Value of Tar and Pitch (Alcan)1This standard is issued under the fixed designation D4715; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi

2、on. 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 determination of the cokingvalue of tar and pitch having an ash content not over 0.5 %, asdetermined

3、by Test Method D2415.1.2 Coking values by this test method are higher than thoseobtained by Test Method D2416. See the bias statement inSection 13.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not pu

4、rport 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, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international stand

5、ard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Re

6、ferenced Documents2.1 ASTM Standards:2D850 Test Method for Distillation of Industrial AromaticHydrocarbons and Related MaterialsD2415 Test Method for Ash in Coal Tar and PitchD2416 Test Method for Coking Value of Tar and Pitch(Modified Conradson)D4296 Practice for Sampling PitchE11 Specification for

7、 Woven Wire Test Sieve Cloth and TestSieves3. Summary of Test Method3.1 A test portion of the tar or pitch is heated for a specifiedtime at 550 C 6 10 C in an electric furnace. The percentageof residue is reported as the coking value.4. Significance and Use4.1 This test method is useful for indicati

8、ng the relativecoke-forming propensities and for evaluating and characteriz-ing tars and pitches. The test method can also be used as oneelement in establishing the uniformity of shipments or sourcesof supply.5. Apparatus5.1 Porcelain Crucible, tall form, 30 mL capacity, height of37 mm and diameter

9、43 mm, with lids of the overlapping type.5.2 Nickel Crucible, 100 mL to 130 mL capacity, height of64 mm and diameter of 60 mm, with lids.5.3 Wire SupportStainless steel wire support, fitting intothe nickel crucible, used to keep the porcelain crucible (5.1)inplace within the nickel crucible (5.2). T

10、his support shall allowa separation of 10 mm 6 1 mm between the bases of the twocrucibles (see Fig. 1).5.4 Crucible TrayA suitable crucible tray to support thenickel crucibles should be made so that there is at least 7 mmof space between the bottom of the crucible and the base of thefurnace.5.5 Elec

11、tric Furnace, capable of being controlled at 550 C6 10 C.5.6 Sieves1 mm (U.S. Standard No. 18), 300 m(U.S. Standard No. 50) and 212 m (U.S. Standard No. 70),conforming to Specification E11.6. Reagents and Materials6.1 Calcined Petroleum CokeUse the fraction whichpasses a 1 mm mesh sieve (U.S. Standa

12、rd No. 18) and isretained by a 212 m mesh sieve (U.S. Standard No. 70).7. Bulk Sampling7.1 Samples from shipments shall be taken in accordancewith Practice D4296, and shall be free of foreign substances.Thoroughly mix the sample immediately before removing arepresentative portion for the determinati

13、on or for dehydration.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.Current edition approved Oct. 1, 2017. Publishe

14、d November 2017. Originallyapproved in 1987. Last previous edition approved in 2012 as D4715 98 (2012).DOI: 10.1520/D4715-98R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informatio

15、n, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization es

16、tablished in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.18. Dehydration of Sample8.1 Hard PitchIf the solid bulk sample contains freewater, air-dry a represent

17、ative portion.8.2 Soft PitchIf the presence of water is indicated bysurface foam on heating, maintain a representative portion ofthe bulk sample at a temperature between 125 C and 150 C inan open container until the surface is free from foam. Take carenot to overheat, and remove heat source immediat

18、ely whenfoam subsides.8.3 TarDehydrate a representative portion of the bulksample at atmospheric pressure using a simple side-armdistillation apparatus similar to the one in Test Method D850and stop the distillation when the temperature reaches 170 C.Separate any oil from the water that has distille

19、d over (ifcrystals are present, warm sufficiently to ensure their solution),and thoroughly mix the oil with the residual tar in the still afterthe latter has cooled to a moderate temperature.9. Preparation of Working Specimen9.1 Hard PitchIf the pitch can be crushed at roomtemperature, prepare a 20

20、g 6 1 g working specimen bysuitable crushing, mixing, and quartering of a representativeportion of the dry specimen. The crushing can be performedwith a small jaw crusher and a mortar and pestle. No particlein the representative specimen should be larger than 5 mm inany dimension. Crush this specime

21、n so that it will pass a300 m (U.S. Standard No. 50) mesh sieve. If the ambienttemperature is high, the operation can be facilitated by chillingthe sample beforehand.9.2 Soft Pitch and TarFor soft pitch and tar samples, meltthe sample and take a sufficient amount of the molten mass forthe test. The

22、melting temperature must not exceed 150 C andthe melting period not longer than 10 min. It is also possible totransfer the required portion of a soft pitch directly to theporcelain crucible, without preliminary treatment.9.3 Preservation of SamplesStore samples as large lumpsor as solidified melts i

23、n closed containers. Discard workingsamples 24 h after crushing and sieving as changes in compo-sition sometimes occur in pulverized pitch.10. Procedure10.1 For greater accuracy, carry out the determination induplicate.10.2 Heat a clean porcelain crucible with its lid in theelectric furnace, control

24、led at 550 C 6 10 C, for 2 h. Aftercooling to ambient temperature in a desiccator, weigh to thenearest 1 mg.10.3 Weigh into the crucible, to the nearest 1 mg, a repre-sentative portion of 1 g 6 0.05 g of the test specimen. Place thewire support in the nickel crucible and make a bed 10 mm 61 mm thick

25、 on the base of the crucible with the petroleum coke.Place the porcelain crucible containing the test portion in thewire support so that it sits on the bed of petroleum coke. Coverthe porcelain crucible with its lid and completely fill the spacebetween the two crucibles with the petroleum coke so th

26、at theporcelain crucible is completely embedded. Take care to avoidcontamination of the sample by the coke. Cover the nickelcrucible with its lid.10.4 Place the prepared crucible on the crucible support andplace the whole in the electric furnace controlled at 550 C 610 C, as quickly as possible, in

27、order to avoid heat losses.10.4.1 There should be a space of not less than 7 mmbetween the nickel crucible and the floor, walls, and roof of thefurnace. The space between the crucible and the door, and theback wall of the furnace should not be less than 5 cm.10.5 After 2.5 h, remove the nickel cruci

28、ble from thefurnace and allow to cool for 5 min to 10 min. Lift theporcelain crucible out of the coke by means of the wiresupport, brush and wipe free from adhering coke powder,taking care to avoid contamination. Place the crucible andcontents, covered, in a desiccator and allow to cool to ambientte

29、mperature. Weigh to the nearest 1 mg.NOTE 1To clean the porcelain crucibles and lids, discard the residuesand burn off carbonaceous matter by igniting at 700 C to 1000 C in anelectric furnace.11. Calculation11.1 Calculate the coking value of the sample as follows:Coking value, mass% 5 100A/B (1)wher

30、e:A = mass of residue, g, andB = mass of sample, g.11.1.1 If the determination was carried in duplicate, reportthe mean value.12. Report12.1 Report the coking value to the nearest 0.1 % by mass.13. Precision and Bias13.1 The following criteria shall be used for judging theacceptability of results (9

31、5 % probability).13.1.1 RepeatabilityDuplicate values by the same opera-tor shall not be considered suspect unless the determinedpercentages differ by more than 1.2 % absolute.13.1.2 ReproducibilityThe values reported by each of twolaboratories, representing the arithmetic average of duplicatedeterm

32、ination, shall not be considered suspect unless thereported percentages differ by more than 2.3 % absolute.FIG. 1 Assembly of Nickel and Porcelain CruciblesD4715 98 (2017)213.2 BiasCoking values by this test method are about 2percentage points higher than those obtained by Test MethodD2416.14. Keywo

33、rds14.1 Alcan; coke-forming; coking value; fixed carbon;pitch; residue; tarASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity

34、 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 andif not revised, either reapproved or withdrawn. Your comments

35、 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 committee, which you may attend. If you feel that your comments have not

36、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 19428-2959,United States. Individual reprints (single or multiple copie

37、s) 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 Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 98 (2017)3