1、Designation: D721 17Designation: 158/69(85)Standard Test Method forOil Content of Petroleum Waxes1This standard is issued under the fixed designation D721; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、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 U.S. Department of Defense.1. Scope*1.1 This test method covers the determination of o
3、il inpetroleum waxes having a congealing point of 30 C (86 F) orhigher as determined in accordance with Test Method D938,and containing not more than 15 % of oil.2NOTE 1With some types of waxes, of oil contents greater than 5 %,there may be an incompatibility with MEK resulting in the formation oftw
4、o liquid phases. If this occurs, the test method is not applicable to thematerial under test.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered s
5、tandard.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-bility of regulatory limitations prior to use.1.4 Thi
6、s international standard 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
7、(TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3D938 Test Method for Congealing Point of PetroleumWaxes, Including PetrolatumE1 Specification for ASTM Liquid-in-Glass ThermometersE128 Test Method for Maximum Pore Diameter and Perme-ability of Rigid Porous Filters for Laboratory UseE2251 S
8、pecification for Liquid-in-Glass ASTM Thermom-eters with Low-Hazard Precision Liquids2.2 Energy Institute Standards:Specification for IP Standard Thermometers43. Summary of Test Method3.1 The sample is dissolved in methyl ethyl ketone, thesolution cooled to 32 C (25 F) to precipitate the wax, andfil
9、tered. The oil content of the filtrate is determined byevaporating the methyl ethyl ketone and weighing the residue.4. Significance and Use4.1 The oil content of a wax may have significant effects onseveral of its properties, such as strength, hardness, flexibility,scuff resistance, coefficient of f
10、riction, coefficient of expansion,melting point, and oil straining. The importance of these effectsmay be dependent upon the ultimate use of the wax.5. Apparatus5.1 Filter Stick and Assembly, consisting of a 10 mm diam-eter sintered glass filter stick of 10 m to 15 m maximum porediameter as determin
11、ed by the method in Appendix X1,provided with an air pressure inlet tube and delivery nozzle. Itis provided with a ground-glass joint to fit a 25 mm by 170 mmtest tube. The dimensions for a suitable filtration assembly areshown in Fig. 1.1This test method is under the jurisdiction of ASTM Committee
12、D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.10.0A on Physical/Chemical Properties.Current edition approved May 1, 2017. Published June 2017. Originallyapproved in 1943. Last previous edition approved in 2015 as D721 15. DOI:10.1520/D0721
13、-17.In the IP, this test method is under the jurisdiction of the StandardizationCommittee. This test method was issued as a joint ASTM-IP tentative in 1964.This test method was prepared jointly by the Technical Association of Pulp andPaper Industry and ASTM International.This test method has been ad
14、opted for use by government agencies to replaceMethod 5431 of Federal Test Method Standard No. 79lb.2This test method is being used by some laboratories for products of higher oilcontent.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at servicea
15、stm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,U.K.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100
16、 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 established in the Decision on Principles for theDevelopment of International Standards, Guides and Re
17、commendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1NOTE 2A metallic filter stick may be employed if desired. A filterstick made of stainless steel and having a 12.7 mm (12 in.) disk of 10 mto 15 m maximum pore diameter, as determined by Test Method E128
18、,has been found to be satisfactory.5The metallic apparatus is inserted intoa 25 mm by 150 mm test tube and held in place by means of a cork.5.2 Cooling Bath, consisting of an insulated box with30 mm 6 5 mm (1.2 in. 6 0.2 in.) holes in the center toaccommodate any desired number of test tubes. The ba
19、th maybe filled with a suitable medium such as kerosine, and may becooled by circulating a refrigerant through coils, or by usingsolid carbon dioxide. A suitable cooling bath to accommodatethree test tubes is shown in Fig. 2.5.3 Pipet, or equivalent dispensing device capable of deliv-ering 1 g 6 0.0
20、5 g of molten wax.5.4 Transfer Pipet, or equivalent volume dispensing device,capable of delivering 15 mL 6 0.06 mL.5.5 Air Pressure Regulator, designed to supply air to thefiltration assembly (8.5) at the volume and pressure required togive an even flow of filtrate. Either the conventional pressure-
21、reducing valve or a mercury bubbler-type regulator has beenfound satisfactory. The latter type, illustrated in Fig. 3, consistsof a 250 mL glass cylinder and a T-tube held in the cylinder bymeans of a rubber stopper grooved at the sides to permit theescape of excess air. The volume and pressure of t
22、he airsupplied to the filtration assembly is regulated by the depth towhich the T-tube is immersed in mercury at the bottom of thecylinder. Absorbent cotton placed in the space above themercury prevents the loss of mercury by spattering. The airpressure regulatory is connected to the filter stick an
23、d assemblyby means of rubber tubing.5.6 Temperature-Measuring Device:5.6.1 Thermometer, having a range as shown below andconforming to the requirements as prescribed in SpecificationE1, Specification E2251, or in the Specification for IP StandardThermometers.Thermometer NumberTemperature Range ASTM
24、IP38 C to +50 C S5C .36 F to +120 F S5F .37 C to +21 C 71C 72C35 F to +70 F 71F 72F5.6.2 Temperature-measuring devices other than those de-scribed in 5.6.1 are satisfactory for this test method, providedthat they exhibit the same temperature response as the equiva-lent mercury-in-glass thermometers.
25、5.7 Weighing Bottles, glass-stoppered, having a typical ca-pacity of 15 mL to 25 mL.5.8 Evaporation Assembly, consisting of an evaporatingcabinet and connections, essentially as illustrated in Fig. 4, andcapable of maintaining a temperature of 35 C 6 1 C (95 F6 2 F) around the evaporation flask. Con
26、struct the jets with aninside diameter of 4 mm 6 0.2 mm for delivering a stream ofclean, dry air vertically downward into the weighing bottle.Support each jet so that the tip is 15 mm 6 5 mm above thesurface of the liquid at the start of the evaporation. Supplypurified air at the rate of 2 L min to
27、3 L min per jet. One wayto purify the air is by passage through a tube of approximately10 mm bore packed loosely to a height of approximately200 mm with absorbent cotton. Periodically check the cleanli-ness of the air by evaporating 4 mL of methyl ethyl ketone bythe procedure specified in 8.5. When
28、the residue does notexceed 0.1 mg, the evaporation equipment is operating satis-factorily.5.9 Analytical Balance, capable of reproducing weights to0.1 mg.5.10 Wire StirrerA piece of stiff wire, made of iron,stainless steel, or Nichrome wire of about No. 20B thenimmediately immerse in the mixture the
29、 clean, dry filter stickwhich has previously been cooled by placing it in a test tubeand holding at 34.5 C 6 1.0 C (30.0 F 6 2.0 F) in thecooling bath for a minimum of 10 min. Seat the ground-glassjoint of the filter so as to make an airtight seal. Place anunstoppered weighing bottle, previously wei
30、ghed together withthe glass stopper to the nearest 0.1 mg, under the deliverynozzle of the filtration assembly.NOTE 7Take every precaution to ensure the accuracy of the weight ofthe stoppered weighing bottle. Prior to determining this weight, rinse theclean, dry weighing bottle and stopper with meth
31、yl ethyl ketone, wipe dryon the outside with a cloth, and place in the evaporation assembly to dryfor about 5 min. Then remove the weighing bottle and stopper, place nearthe balance, and allow to stand for 10 min prior to weighing. Stopper thebottle during this cooling period. Once the weighing bott
32、le and stopperhave been dried in the evaporation assembly, lift only with forceps. Takecare to remove and replace the glass stopper with a light touch.8.5 Apply air pressure to the filtration assembly, and imme-diately collect about 4 mL of filtrate in the weighing bottle.Release the air pressure to
33、 permit the liquid to drain backslowly from the delivery nozzle. Remove the weighing bottleimmediately, and stopper and weigh to at least the nearest10 mg without waiting for it to come to room temperature.Unstopper the weighing bottle and place it under one of the jetsin the evaporation assembly ma
34、intained at 35 C 6 1 C (95 F6 2 F), with the air jet centered inside the neck, and the tip15 mm 6 5 mm above the surface of the liquid. After thesolvent has evaporated, which usually takes less than 30 min,remove the bottle and stopper, and place them near the balance.Allow to stand for 10 min and w
35、eigh to the nearest 0.1 mg.Repeat the evaporation procedure, using a 5 min evaporationperiod instead of 30 min, until the loss between successiveweighings is not over 0.2 mg.9. Calculation9.1 Calculate the amount of oil in the wax as follows:Oil in wax, weight % 5 100 AC/BD! 2 0.15 (1)where:A = weig
36、ht of oil residue, g,B = weight of wax sample, g,C = weight of solvent, g, obtained by subtracting weightof test tube plus wax sample (8.1) from weight oftest tube and contents (8.2),D = weight of solvent evaporated, g, obtained by sub-tracting weight of weighing bottle plus oil residuefrom weight o
37、f weighing bottle plus filtrate (8.5),andAll dimensions are in millimetresFIG. 3 Air Pressure RegulatorD721 1740.15 = average factor correcting for the solubility of wax inthe solvent at 32 C (25 F).10. Report10.1 Report the result as oil content, Test Method D721. Ifthe result is negative, report a
38、s zero.11. Precision and Bias11.1 PrecisionThe precision of this test method as deter-mined by statistical examination of interlaboratory results is asfollows:11.1.1 RepeatabilityThe difference between two testresults, obtained by the same operator with the same apparatusunder constant operating con
39、ditions on identical test material,would in the long run, in the normal and correct operation ofthe test method, exceed the following values only in one casein twenty:0.0618% of the mean11.1.2 ReproducibilityThe difference between two singleand independent results obtained by different operators wor
40、k-ing in different laboratories on identical test material would, inAll dimensions are in millimetres (inches)FIG. 4 Evaporation AssemblyD721 175the long run, in the normal and correct operation of the testmethod, exceed the following values only in one case intwenty:0.2111% of the mean11.2 BiasThe
41、procedure in this test method has no biasbecause the value of oil content can be defined only in terms ofa test method.12. Keywords12.1 oil content; petroleum wax; waxAPPENDIX(Nonmandatory Information)X1. TEST METHOD FOR MEASUREMENT OF MAXIMUM PORE DIAMETER OF RIGID POROUS FILTERSX1.1 ScopeX1.1.1 Th
42、is test method covers the determination of theacceptability of porous filter sticks used for filtration in TestMethod D721. This test method establishes the maximum porediameter and also provides a means of detecting and measuringchanges which occur form continued use.X1.2 DefinitionX1.2.1 maximum p
43、ore diameterthe diameter in microm-eters of the largest opening in the filter.NOTE X1.1It is recognized that the maximum pore diameter asdefined herein does not necessarily indicate the physical dimensions of thelargest pore in the filter. It is further recognized that the pores are highlyirregular
44、in shape. Because of the irregularity in shape and otherphenomena characteristic of filtration, a filter may be expected to retain allparticles larger than the maximum pore diameter as defined and deter-mined herein, and will generally retain particles which are much smallerthan the determined diame
45、ter.X1.3 Summary of Test MethodX1.3.1 The filter is cleaned and wetted with water. It is thenimmersed in water and air pressure is applied against its uppersurface until the first bubble of air passes through the filter. Themaximum pore diameter is calculated from the surface tensionof water and the
46、 applied pressure.X1.4 ApparatusX1.4.1 Pressure-Measuring Device, mercury-filled manom-eter or equivalent, capable of measuring pressures in incre-ments of 0.5 mm of Hg.X1.4.2 Air Supply, clean and filtered.X1.4.3 Air Pressure Regulator, needle-valve type.X1.4.4 Drying Oven.X1.5 ProcedureX1.5.1 Clea
47、n the filter sticks by soaking in concentratedhydrochloric acid, and then wash them with distilled water.Rinse with acetone, air dry, and place in drying oven at 220 F(105 C) for 30 min.X1.5.2 Thoroughly wet the clean filter to be tested bysoaking it in distilled water.X1.5.3 Assemble the apparatus
48、as shown in Fig. X1.1.Apply pressure slowly from a source of clean air.X1.5.4 Immerse the filter just below the surface of thewater.NOTE X1.2If a head of liquid exists above the surface of the filter, theback pressure produced must be deducted from the observed pressure.X1.5.5 Increase the air press
49、ure to about 10 mm Hg (orequivalent pressure value if using different units) below theacceptable pressure limit and then at a slow uniform rateequivalent to about 3 mm Hg/min until the first bubble passesthrough the filter. This can be conveniently observed byplacing the beaker or test tube over a mirror. Read thepressure-measuring device when the first bubble passes off theunderside of the filter.FIG. X1.1 Assembly of Apparatus for Checking Pore Diameter orFilter SticksD721 176X1.6 CalculationX1.6.1 Calculate the pore d
