1、Designation: D 3279 07Standard Test Method forn-Heptane Insolubles1This standard is issued under the fixed designation D 3279; 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 indic
2、ates 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 determination of the masspercent of asphaltenes as defined by insolubility in normal-heptane solvent. It is applicable to all solid and s
3、emi-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.1.3 This standard does not purport to address all of the
4、safety 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. See Section 7 for aspecific hazard statement.2. Referenced Documents2.
5、1 ASTM Standards:2C 670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction Materials3. Summary of Test Method3.1 The sample is dispersed in n-heptane and filteredthrough a glass-fiber pad. The insoluble material is washed,dried, and weighed.4. Significance and Use4
6、.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-ponents not soluble in n-heptane.5. Apparatus and Materials5.1 The assembly of the dispersing apparatus is illustrated i
7、nFig. 1 with details of the component parts as follows:5.1.1 Erlenmeyer Flask, of 250-mL capacity adapted to anAllihn-type reflux condenser, each with a 35/25 ball joint.5.1.2 Magnetic Stirrer and Magnetic-Stirrer Hot Plate,equipped with a voltage regulator.5.1.3 Gooch Crucible, glazed inside and ou
8、tside with theexception of the outside bottom surface. The approximatedimensions shall be a diameter of 44 mm at the top tapering to36 mm at the bottom and a depth of 2030mm.5.1.4 Filter Pad, glass-fiber 32 mm in diameter.35.1.5 Filter Flask, heavy-wall with side tube, 500-mLcapacity.5.1.6 Filter Tu
9、be, 40 to 42 mm in inside diameter.5.1.7 Rubber Tubing, or adapter for holding Gooch cru-cible on the filter tube.NOTE 1Other suitable assemblies permitting vacuum filtration with aGooch crucible may be used.6. Solvent6.1 n-Heptane, 99.0 minimum mol % (Pure Grade).7. Hazards7.1 n-Heptane has a boili
10、ng point of 98C and a flash pointof 1C, which means that it should be handled with care. It isrecommended that both the reflux dispersion and filtrationsteps be conducted in a ventilated hood and away from flamesor other sources of heat.8. Procedure8.1 Into the 250-mL Erlenmeyer flask, weigh to the
11、nearest0.1 mg a quantity of the sample to be tested, using 0.5 to 0.6g for airblown asphalts, 0.7 to 0.8 g for asphalt paving bindersand crude residues, and 1.0 to 1.3 g for gas oils and heavy fueloils (Note 2).Add n-heptane in the ratio 100 mL of solvent per1 g of sample, using proportionally less
12、or more solvent asdependent upon the sample size. Unless the asphalt is in agranular form, heat the flask gently and turn it to cause thesample to be distributed somewhat over the bottom or lowersides of the flask.NOTE 2Tests show a small amount of insolubles (60.3 mass %)remain on walls of the prec
13、ipitation flask despite repeated washings.Whenexpected level of nC7insolubles is 6 % or less, use of a tared 250-mL1This 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.Curre
14、nt edition approved Aug. 1, 2007. Published August 2007. Originallyapproved in 1973. Last previous edition approved in 2001 as D 3279 97 (2001).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards v
15、olume information, refer to the standards Document Summary page onthe ASTM website.3Glass filter pads No. 934-AH (Huribut) may be purchased from Reeve Angeland Company, Clifton, NJ.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Erle
16、nmeyer flask is recommended. After all possible precipitate has beenwashed from the flask to the filtering crucible in 8.3, include the flask withthe crucible for the drying, weighing, and calculation procedures in 8.3and 9.1.8.2 Place the Erlenmeyer flask, containing the sample plussolvent with mag
17、netic stirrer added, on the magnetic-stirrer hotplate and secure under the reflux condenser. With the magneticstirrer in operation, adjust for gentle refluxing for a period of15 to 20 min when testing paving binders, fuel oils, gas oils, orcrude residues. For airblown asphalts, a reflux period of 25
18、 to30 min is recommended. In all cases, allow the dispersedmixture to cool to room temperature for a period of 1 h.8.3 Place the Gooch crucible plus one thickness of theglass-fiber filter pad in an oven at about 107C for 15 min,allow to cool in a desiccator, and then weigh to the nearest 0.1mg. Set
19、up the filtering crucible plus filter pad in the suctionflask and pre-wet with 5 mL of 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 wil
20、lproceed most rapidly if the supernatant liquid is filtered firstwith the insolubles 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 portio
21、ns ofn-heptane of about 10 mL each, first rinsing out the flasktherewith. Place the crucible in the 107C oven for a period of15 min, cool in a desiccator, and weigh.9. Calculation and Report9.1 Calculate the mass percent of normal-heptane insolubles(NHI) as the percentage by weight of the original s
22、ample asfollows:NHI, % 5 A/B! 3 100 (1)where:A = total mass of insolubles, andB = total mass of sample.For percentages of insolubles less than 1.0, report to the nearest0.01 %; for percentages of insolubles of 1.0 or more, report tothe nearest 0.1 %.10. Precision and Bias10.1 Precision of the method
23、 has been determined as fol-lows:Standard DeviationAAcceptable Range ofTwo ResultsASingle-operator 0.53 % NHI 1.51 % NHIMultilaboratory 0.93 % NHI 2.78 % NHI_AThese numbers represent, respectively, the (1S) and (D2S) limits as describedin Practice C 670. The precision is for samples covering a range
24、 from 4.0 to 29.0 %HI.11. Keywords11.1 asphaltenes; heptane insolublesD3279072FIG. 1 Dispersing ApparatusD3279073FIG. 2 Filtration ApparatusASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this
25、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
26、 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
27、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 19428-2959,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).D3279074
