ASTM D4893-1994(2004) Standard Test Method for Determination of Pitch Volatility《测定硬沥青挥发性的标准试验方法》.pdf

1、Designation: D 4893 94 (Reapproved 2004)An American National StandardStandard Test Method forDetermination of Pitch Volatility1This standard is issued under the fixed designation D 4893; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi

2、on, the year of last revision. A number in parentheses indicates 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 the determination of the percentof pitch volatility.1.2 Since this test metho

3、d is empirical, strict adherence tothe procedure is necessary.1.3 The values stated in SI units are to be regarded as thestandard.1.4 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 establis

4、h appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Summary of Test Method2.1 An aluminum weighing dish with about 15 g of speci-men is introduced into the cavity of a metal block heated andmaintained at 350C (662F). After 30 min 6 10

5、 s duringwhich the volatiles are swept away from the surface of theliquid pitch by preheated nitrogen, the sample is taken out andallowed to cool down in the desiccator. The pitch volatility isdetermined by the sample weight loss and reported as percentweight loss.3. Significance and Use3.1 This tes

6、t is useful in evaluating and characterizing pitchphysical properties in comparing the consistency of shipmentsand sources of supply.4. Apparatus4.1 Aluminum Block,2412-in. outside diameter, composedof two sections (Figs. 1-4).4.1.1 The top block is maintained at a chosen constanttemperature accordi

7、ng to the signal from the thermocoupleinserted into the thermowell No. 1 near the center of the block.A proportional temperature controller regulates the heat input.Two insulated handles are attached to this part for easyhandling. An additional thermowell No. 2, located in the centerof the block, ac

8、commodates another thermocouple used onlyfor the determination of the rate of temperature rise of thepitch. When the screw at the bottom of the No. 2 well is takenout, the thermocouple can then be pushed down and inserted inpitch.4.1.2 The bottom block has a cavity for the aluminumweighing dish.Aspi

9、ral channel cut around the periphery of thispart serves for preheating the nitrogen introduced at themeasured rate (10 cm3/min) into the block for purging vola-tiles.4.1.3 The test temperature, the same as that in the top block,is maintained by the second proportional temperature control-ler accordi

10、ng to the signals of a thermocouple inserted in athermowell No. 3 of the bottom block. There is a hole in thecenter of the bottom cylinder to accommodate the sampleplatform, a rod with a stainless steel disk welded to its top. Thealuminum sample dish containing the sample rests on top ofthis disk du

11、ring the test. The aluminum sample dish can belifted out of the cavity by raising the disk up to the upper rimof the cavity.4.2 Aluminum Weighing Dish.34.3 Flowmeter, 0 to 25-cm3/min range.4.4 Nitrogen Cylinder, equipped with a pressure regulator.4.5 Timer, with an alarm.4.6 Aluminum Plate, 5-by-5-i

12、n., approximately 20-gage.5. Dehydration of Sample5.1 Hard PitchIf the solid bulk sample contains freewater, air-dry a representative portion in a forced-draft oven at50C (122F).5.2 Soft Pitch (Softening Point 60C (140F)If thepresence of water is indicated by surface foam on heating,maintain a repre

13、sentative portion of the bulk sample at atemperature between 125 and 150C (251 and 302F) in anopen container until the surface is free of foam. Take care notto overheat, and remove heat source immediately when foamsubsides.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum

14、 Products and Lubricants and is the direct responsibility of SubcommitteeD02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.Current edition approved Nov. 1, 2004. Published November 2004. Originallyapproved in 1989. Last previous edition approved in 1999 as D 4893 94 (1999).2An alumin

15、um block that may be obtained on special order from KoppersCompany, Inc., 1005 Wm. Pitt Way, Pittsburgh, PA 15238, has been foundsatisfactory for this purpose; or drawings of block will be furnished by Koppersupon request. If you are aware of alternative suppliers, please provide thisinformation to

16、ASTM International Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee1, whichyou may attend.3Fisher Catalog Number 08-732 or VWR Scientific Catalog Number 25433-008has been found satisfactory for this purpose.1Copyright ASTM Internationa

17、l, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Preparation of Working Sample6.1 Crush sample to pass No. 4 mesh (4760 m).7. Preparation of Apparatus7.1 Assemble the apparatus so that the exit opening in theupper block is aligned with bottom nitrogen inlet f

18、itting of thebottom block. Both top and bottom blocks are heated to the testtemperature, 350C (662F), using the proportional tempera-ture controllers. Avoid heating the upper block and lower blockwhen separated from each other.8. Procedure8.1 Weigh 15 g of prepared sample into a tared aluminumweighi

19、ng dish with precision of 0.1 mg.8.2 Start nitrogen purge system at a rate 10 cm3/min 6 0.1cm3/min (10 mL/min 6 0.1 mL/min).8.3 Place top block onto bottom block, align the nitrogeninlet with nitrogen outlet, and heat to test temperature of 350C(662F).8.4 Remove top block. Raise the sample platform

20、upslightly above the rim of heating cavity and support with thealuminum plate inserted between the sample platform and toprim of the bottom block. Place the aluminum sample dishcontaining the sample onto the sample platform. Remove theinserted aluminum plate from below the sample platform andlower t

21、he sample carefully into the heated cavity. Close thebottom block with the top block and realign the nitrogen inletwith nitrogen outlet. This operation should be performed asquickly as possible to avoid excessive heat loss from the heatedcavity.8.5 Heat for 30 min 6 10 s. Remove top block, raise sam

22、pleplatform, insert aluminum plate under the sample platform,sweep the sample off the sample platform on to the plate, andset aside.8.6 Close the bottom block with the top block, realign thenitrogen inlet and outlet and allow the temperature in theblocks to stabilize before inserting subsequent samp

23、le.FIG. 1 Schematic of the Volatility ApparatusD 4893 94 (2004)28.7 When sample has cooled, approximately 2 min afterremoval or when crust has formed on top of sample, setaluminum dish containing sample into desiccator for 30 min.Determine weight loss.8.8 Report in percent, mass loss for test temper

24、ature, 350C.V 5 b 3 100!/a (1)where:V = volatility, %, mass loss,b = mass loss, g, anda = net mass of sample, g.8.9 The exit opening of nitrogen purge, the sample platform,and the seat between the blocks must be kept free of deposits.For cleaning use acetone and a drill bit for opening the nitrogene

25、xit.9. Determination of Unit Heat-up Rate9.1 The volatility test temperature should be maintained atthe same level for the total duration of the test. Because this isnot possible, the required temperature level should be reachedwithin the shortest time after placing the sample into thepreheated bloc

26、ks. The heat-up rate is determined with aselected control pitch sample. The temperature of pitch ismeasured and recorded with the provided thermocouple and aseparate temperature indicator (not provided). For that reasonthe thermocouple is introduced through the upper block afterremoving the closing

27、screw and its immersion in the pitchsample is adjusted so that it is covered with pitch but does nottouch the bottom of the aluminum weighing dish.9.2 The procedure for preheating the blocks and introducingthe pitch sample into the cavity of the volatility apparatus isidentical to the actual volatil

28、ity procedure.9.3 The temperature of pitch should level off, that is, thetemperature rise should become less than 1C/min, within theinterval not longer than 10 min after the start of the experiment.Plot time versus temperature, taking data every 2 min (Fig. 5).10. Precision410.1 RepeatabilityDuplica

29、te values by the same operatorshall not be considered suspect unless they differ by more than0.2 %.10.2 ReproducibilityThe values reported by each of twolaboratories representing the arithmetic average of duplicatedeterminations shall not be considered suspect unless thevalues differ by more than 0.

30、3 %.11. Keywords11.1 coal; pitch; tar; volatility4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: :D08-1004.FIG. 2 Internal Schematic Lower BlockD 4893 94 (2004)3FIG. 3 Schematic External Bottom BlockD 4893 94 (2004)4FIG. 4 Sche

31、matic Top BlockD 4893 94 (2004)5ASTM 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 of any such patent rights, and the riskof

32、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 are invited either for revision of this st

33、andard 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 received a fair hearing you shouldmake your

34、 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).FIG. 5 Temperature Rise Measured in a Calibration SampleD 4893 94 (2004)6