1、Designation: D3279 121Standard Test Method forn-Heptane Insolubles1This standard is issued under the fixed designation D3279; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indica
2、tes the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTESection 8.1 was editorially corrected in March 2016.1. Scope1.1 This test method covers determination of the masspercent of asphaltenes as defined by insolubility in norm
3、al-heptane solvent. It is applicable to all solid and semi-solidpetroleum asphalts containing little or no mineral matter, to gasoils, to heavy fuel oils, and to crude petroleum that has beentopped to a cut-point of 343C or higher.1.2 The values stated in SI units are to be regarded as thestandard.
4、No other units of measurement are included in thisstandard.1.3 This standard does not purport 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-bi
5、lity of regulatory limitations prior to use. See Section 7 for aspecific hazard statement.2. Referenced Documents2.1 ASTM Standards:2C670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction Materials3. Summary of Test Method3.1 The sample is dispersed in n-heptane a
6、nd filteredthrough a glass-fiber pad. The insoluble material is washed,dried, and weighed.4. Significance and Use4.1 This test method is useful in quantifying the asphaltenecontent of petroleum asphalts, gas oils, heavy fuel oils, andcrude petroleum. Asphaltene content is defined as those com-ponent
7、s not soluble in n-heptane.5. Apparatus and Materials5.1 The assembly of the dispersing apparatus is illustrated inFig. 1 with details of the component parts as follows:5.1.1 Erlenmeyer Flask, of 250-mL capacity adapted to anAllihn-type reflux condenser.5.1.2 Magnetic Stirrer and Magnetic-Stirrer Ho
8、t Plate5.1.3 Bitumen Crucible or Gooch Crucible, glazed insideand outside with the exception of the outside bottom surface.The approximate dimensions shall be a diameter of 44 mm atthe top tapering to 36 mm at the bottom and a depth of2030 mm.5.1.4 Glass Microfiber Filter Pad, 3234 mm in diameterfin
9、e porosity, fast flow rate, 1.5m particle retention.5.1.5 Filter Flask, heavy-wall with side tube, 500-mLcapacity.5.1.6 Filter Tube, 40 to 42 mm in inside diameter.5.1.7 Rubber Tubing, or adapter for holding Gooch crucibleon the filter tube.NOTE 1Other suitable assemblies permitting vacuum filtratio
10、n with acrucible may be used.5.1.8 Oven, capable of maintaining a temperature of 110 65C.6. Reagent6.1 n-Heptane, 99.0 minimum mol % (Pure Grade).7. Hazards7.1 n-Heptane has a boiling point of 98C and a flash pointof 1C, which means that it should be handled with care. It isrecommended that both the
11、 reflux dispersion and filtrationsteps be conducted in a ventilated hood and away from flamesor other sources of heat.8. Preparation of Crucible8.1 Place the Gooch crucible plus one thickness filter pad inan oven at about 110 6 5C for 30 min, allow to cool in adesiccator for 30 6 5 min, and then det
12、ermine the mass to thenearest 0.1 mg. Designate this mass as A. Store in a desiccatoruntil ready for use.1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.47 onMiscellaneous Asphalt Tests.Current edition
13、 approved Dec. 1, 2012. Published December 2012. Originallyapproved in 1973. Last previous edition approved in 2007 as D3279 07. DOI:10.1520/D3279-12E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMSt
14、andards volume information, 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 States19. Sample Preparation9.1 If the sample is not fluid, heat to any convenienttemperature, but in
15、 any case not more than 100C above thesoftening point.10. Procedure10.1 Note Safety precautions in Section 7. Transfer into thetared 250-mL Erlenmeyer flask, the approximate amount ofsample to be tested. Use 0.5 to 0.6 g for airblown asphalts, 0.7to 0.8 g for asphalt paving binders and crude residue
16、s, and 1.0to 1.3 g for gas oils and heavy fuel oils (Note 2). Allow thesample to cool to ambient temperature and determine the massto the nearest 1mg. Designate this mass as B.Add n-heptane inthe ratio 100 mL of solvent per1gofsample, usingproportionally less or more solvent as dependent upon thesam
17、ple size. Unless the asphalt is in a granular form, heat theflask gently and turn it to cause the sample to be distributedsomewhat over the bottom or lower sides of the flask.NOTE 2Tests show a small amount of insolubles (60.3 mass %)remain on walls of the precipitation flask despite repeated washin
18、gs.Whenexpected level of nC7insolubles is 6 % or less, use of a tared 250-mLErlenmeyer flask is recommended. After all possible precipitate has beenwashed from the flask to the filtering crucible in 10.3, include the flaskwith the crucible for the drying, weighing, and calculation procedures in10.3
19、and 11.1.10.2 Place the Erlenmeyer flask, containing the sample plussolvent with magnetic stirrer added, on the magnetic-stirrer hotplate and secure under the reflux condenser. With the magneticstirrer in operation, adjust the heat for gentle refluxing for aperiod of 15 to 20 min when testing paving
20、 binders, fuel oils,gas oils, or crude residues. For airblown asphalts, a refluxperiod of 25 to 30 min is recommended. In all cases, allow thedispersed mixture to cool to room temperature for a period of1h.10.3 Set up the filtering crucible plus filter pad in the suctionflask and pre-wet with 5 mL o
21、f n-heptane (see Fig. 2). Warmthe flask containing the sample plus solvent to 38 to 49C onthe hot plate and pour its contents (except for the magneticstirrer) through the filter using a gentle vacuum. Filtration willproceed most rapidly if the supernatant liquid is filtered firstwith the insolubles
22、transferred to the filter last. Police thebeaker or flask while transferring the final precipitate, usingeither a rubber policeman or stainless steel spatula with asquared end. Wash the precipitate with three portions ofn-heptane of about 10 mL each, first rinsing out the flasktherewith. Place the c
23、rucible in the 110 6 5C oven for a periodof 30 min, cool in a desiccator, and determine the mass to thenearest 0.1 mg. Designate this mass as C.11. Calculation and Report11.1 Calculate the mass percent of normal-heptane in-solubles (NHI) as the percentage by weight of the originalsample as follows:w
24、here:A = mass of crucible and filterB = total mass of sample.C = mass of crucible, filter, and insoluble materialFor percentages of insolubles less than 1.0, report to thenearest 0.01 %; for percentages of insolubles of 1.0 or more,report to the nearest 0.1 %.12. Precision and Bias12.1 Precision of
25、the method has been determined as fol-lows:Standard DeviationAAcceptable Range ofTwo ResultsASingle-operator 0.53 % NHI 1.51 % NHIMultilaboratory 0.93 % NHI 2.78 % NHIAThese numbers represent, respectively, the (1S) and (D2S) limits as described inPractice C670. The precision is for samples covering
26、 a range from 4.0 to 29.0 %HI.13. Keywords13.1 asphaltenes; heptane insolublesD3279 1212FIG. 1 Dispersing ApparatusD3279 1213ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned inthis standard. Users of this standard are ex
27、pressly 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 andif not revi
28、sed, 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 committee, which you ma
29、y 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 19428-2959,United Sta
30、tes. 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 Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 2 Filtration ApparatusD3279 1214
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