1、Designation: D4893 94 (Reapproved 2015)1Standard Test Method forDetermination of Pitch Volatility1This standard is issued under the fixed designation D4893; 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.1NOTESI units formatting was corrected editorially in May 2015.1. Scope1.1 This test method covers the determination of the percentof pitch vola
3、tility.1.2 Since this test method is empirical, strict adherence tothe procedure is necessary.1.3 The values stated in SI units are to be regarded as thestandard. The values in parentheses are given for informationonly.1.3.1 ExceptionsThe diameter of a special aluminumblock is measured in inches.1.4
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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Summary of Test
5、 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 350 C (662 F). After 30 min 6 10 s duringwhich the volatiles are swept away from the surface of theliquid pitch by preheated nitrogen, the sample is taken out anda
6、llowed 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 test is useful in evaluating and characterizing pitchphysical properties in comparing the consistency of shipmentsand sources of suppl
7、y.4. Apparatus4.1 Aluminum Block,2412 in. outside diameter, composed oftwo sections (Figs. 1-4).4.1.1 The top block is maintained at a chosen constanttemperature according to the signal from the thermocoupleinserted into the thermowell No. 1 near the center of the block.A proportional temperature co
8、ntroller 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, accommodates another thermocouple used onlyfor the determination of the rate of temperature rise of thepitch. When the screw at the b
9、ottom 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.Aspiral channel cut around the periphery of thispart serves for preheating the nitrogen introduced at themeasured rate (10 cm3/min) int
10、o 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 according to the signals of a thermocouple inserted in athermowell No. 3 of the bottom block. There is a hole in thecenter of the bottom c
11、ylinder 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 during 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 Alu
12、minum Weighing Dish.4.3 Flowmeter, 0cm3/min to 25 cm3/min range.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.Curre
13、nt edition approved April 1, 2015. Published May 2015. Originallyapproved in 1989. Last previous edition approved in 2009 as D4893 94 (2009).DOI: 10.1520/D4893-94R15E01.2An aluminum block that may be obtained on special order from KoppersCompany, Inc., 1005 Wm. Pitt Way, Pittsburgh, PA 15238, has be
14、en 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 ASTM International Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technica
15、l committee,1whichyou may attend.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.4 Nitrogen Cylinder, equipped with a pressure regulator.4.5 Timer, with an alarm.4.6 Aluminum Plate, 127 mm by 127 mm, approximately20-gauge.5. Dehydra
16、tion of Sample5.1 Hard PitchIf the solid bulk sample contains freewater, air-dry a representative portion in a forced-draft oven at50 C (122 F).5.2 Soft Pitch (Softening Point 60 C (140 F )If thepresence of water is indicated by surface foam on heating,maintain a representative portion of the bulk s
17、ample at atemperature between 125 C and 150 C (251 F and 302 F)in an open container until the surface is free of foam. Take carenot to overheat, and remove heat source immediately whenfoam subsides.6. Preparation of Working Sample6.1 Crush sample to pass No. 4 mesh (4760 m).7. Preparation of Apparat
18、us7.1 Assemble the apparatus so that the exit opening in theupper block is aligned with bottom nitrogen inlet fitting of thebottom block. Both top and bottom blocks are heated to the testtemperature, 350 C (662 F), using the proportional tempera-ture controllers. Avoid heating the upper block and lo
19、wer blockwhen separated from each other.8. Procedure8.1 Weigh 15 g of prepared sample into a tared aluminumweighing dish with precision of 0.1 mg.8.2 Start nitrogen purge system at a rate 10 cm3/min 60.1 cm3/min (10 mL min 6 0.1 mL min).8.3 Place top block onto bottom block, align the nitrogeninlet
20、with nitrogen outlet, and heat to test temperature of350 C (662 F).8.4 Remove top block. Raise the sample platform upslightly above the rim of heating cavity and support with thealuminum plate inserted between the sample platform and topFIG. 1 Schematic of the Volatility ApparatusD4893 94 (2015)12ri
21、m 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 the sample carefully into the heated cavity. Close thebottom block with the top block and realign the nitrogen inletwith nitr
22、ogen 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 sampleplatform, insert aluminum plate under the sample platform,sweep the sample off the sample platform on to the plate, andse
23、t 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 sample.8.7 When sample has cooled, approximately 2 min afterremoval or when crust has formed on top of sample, setaluminum dish
24、containing sample into desiccator for 30 min.Determine weight loss.8.8 Report in percent, mass loss for test temperature,350 C.V 5 b 3100!/a (1)where:V = volatility, percent, 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
25、seat between the blocks must be kept free of deposits.For cleaning use acetone and a drill bit for opening the nitrogenexit.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,
26、the required temperature level should be reachedwithin the shortest time after placing the sample into thepreheated blocks. 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 in
27、dicator (not provided). For that reasonthe thermocouple is introduced through the upper block afterremoving the closing 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
28、the blocks and introducingthe pitch sample into the cavity of the volatility apparatus isidentical to the actual volatility procedure.FIG. 2 Internal Schematic Lower BlockD4893 94 (2015)139.3 The temperature of pitch should level off, that is, thetemperature rise should become less than 1 C min, wit
29、hin theinterval not longer than 10 min after the start of the experiment.Plot time versus temperature, taking data every 2 min (Fig. 5).10. Precision310.1 RepeatabilityDuplicate values by the same operatorshall not be considered suspect unless they differ by more than0.2 %.10.2 ReproducibilityThe va
30、lues reported by each of twolaboratories representing the arithmetic average of duplicatedeterminations shall not be considered suspect unless thevalues differ by more than 0.3 %.11. Keywords11.1 coal; pitch; tar; volatility3Supporting data have been filed at ASTM International Headquarters and mayb
31、e obtained by requesting Research Report RR:D08-1004.FIG. 3 Schematic External Bottom BlockD4893 94 (2015)14FIG. 4 Schematic Top BlockD4893 94 (2015)15ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Use
32、rs of this 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
33、 five years 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 technic
34、al committee, 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
35、, 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). 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:/ 5 Temperature Rise Measured in a Calibration SampleD4893 94 (2015)16
