1、Designation:D327912Standard 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 indicates the
2、 year of last reapproval.Asuperscript epsilon()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 semi-solidpetro
3、leum 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.No other units of measurement are included in thisstandard.1.3 This stand
4、ard 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-bility of regulatory limitations prior to use.See Section 7 for aspecific haza
5、rd 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 and filteredthrough a glass-fiber pad.The insoluble material is washed,dried,and
6、 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-ponents not soluble in n-heptane.5.Apparatus and Materials5.1 The assembly of the dispersing
7、 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 Hot Plate5.1.3 Bitumen Crucible or Gooch Crucible,glazed insideand outside with the excepti
8、on 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 of2030mm.5.1.4 Glass Microfiber Filter Pad,3234 mm in diameterfine porosity,fast flow rate,1.5m particle retention.5.1.5 Filter Flask,heavy-wall with side tu
9、be,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.NOTE1Other suitable assemblies permitting vacuum filtration with acrucible may be used.5.1.8 Oven,capable of maintaining a temperature of 110 65C.6.Reagent6.
10、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 reflux dispersion and filtrationsteps be conducted in a ventilated hood and away from flamesor other sourc
11、es 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,and then determine the mass to thenearest 0.1 mg.Designate this mass as A.Store in a desicatoruntil ready for use.9.Sample Pre
12、paration9.1 If the sample is not fluid,heat to any convenienttemperature,but in any case not more than 100C above thesoftening point.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 A
13、sphalt Tests.Current edition approved Dec.1,2012.Published December 2012.Originallyapproved in 1973.Last previous edition approved in 2007 as D3279 07.DOI:10.1520/D3279-12.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual
14、 Book of ASTMStandards 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 States1 10.Procedure10.1 Note Safety precautions in Section 7.Transfer into thetared 250-mL
15、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 residues,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 nassto the nearest
16、1mg.Designate this mass a B.Add n-heptane inthe ratio 100 mL of solvent per 1 g of sample,usingproportionally less or more solvent as dependent upon thesample 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.NOTE2Tests show a small amount of insolubles(60.3 mass%)remain on walls of the precipitation flask despite repeated washings.Whenexpected level of nC7insolubles is 6%or les
