1、Designation: D 7454 08An American National StandardStandard Test Method forDetermination of Vibrated Bulk Density of CalcinedPetroleum Coke using a Semi-Automated Apparatus1This standard is issued under the fixed designation D 7454; the number immediately following the designation indicates the year
2、 oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of bulkdensity
3、 of a representative 2-kg sample of calcined petroleumcoke, after vibration to increase compaction, using a semi-automatic apparatus.1.2 The procedure is applied, but not limited, to particlespassing through a 4.75-mm opening sieve and retained on a1.18-mm opening sieve. Further, the procedure is ap
4、plied, butnot limited, to a specific test sample having particles passingthrough a 0.85-mm opening sieve and retained on a 0.425-mmopening sieve. This procedure could also be applied to othersieve fractions being agreed on in the aluminum industry asspecified in Annex A1.1.3 The values stated in SI
5、units are to be regarded asstandard. No other units of measurement are included in thisstandard.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 establish appro-priate safety and health p
6、ractices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E11 Specification for Wire Cloth and Sieves for TestingPurposes3. Terminology3.1 Definitions:3.1.1 as-calcined particles, nof coke, those particles thathave not been subject to
7、 laboratory crushing.3.1.2 bulk density, nof coke, the ratio of the mass of acollection of particles of a specified particle size range to thevolume occupied.3.1.3 laboratory crushed particles, nof coke, those par-ticles of petroleum coke that have been crushed in thelaboratory.4. Summary of Test Me
8、thod4.1 The natural 4.75 by 1.18-mm fraction of the originalcoke is separated from the sample by manual screening, groundto 0.85 by 0.425 mm, and fed at a controlled rate into agraduated cylinder on a vibrating table until the coke reachesthe 50-mL mark. The collected coke is weighed and the bulkden
9、sity is calculated and reported in g/mL.4.2 The procedure is empirical; close adherence to thetechnique and apparatus is necessary to ensure reproducibleresults. To provide comparable results in different locations,exact adjustments of operating parameters are required usingreference samples.5. Sign
10、ificance and Use5.1 Vibrated bulk density (VBD) is an indicator of calcinedpetroleum coke porosity, which affects its suitability for use inpitch-bonded carbon applications. (WarningVibrated bulkdensity for a sample of calcined petroleum coke is stronglydependent upon average particle size and parti
11、cle size range.Bulk density tends to increase with decreasing coke size. Anarrow particle size range for this test minimizes the possibilityfor variation due to skewing of the test sample toward eitherscreen defining the sample.)6. Apparatus6.1 Pan BalanceAccurate to 0.1 g, with a capacity of2.0 kg.
12、6.2 Riffle SamplerEnclosed drawer, approximately 380 by290 by 360 mm, 24-slot.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.05.0D on Petroleum Coke.Current edition approved Oct. 15, 2008. Publ
13、ished October 2008.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Ha
14、rbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.3 SievesMeeting Specification E11.6.4 Sieve ShakerElectrical drive with an automatic timer;should have a rotating and tapping action.6.5 Roller CrusherLaboratory type; glass hardened rolls;roll diameter of approximately 150 m
15、m; roll width of approxi-mately 150 mm; gap range from 0 to 12.7 mm.6.6 Thickness Gauges (leaf-type)0.4, 1.0, 1.5, and 4.0mm.6.7 Semi-Automated VBD Apparatus, As shown in Fig. 1.See also comments about installation in Annex A1.6.7.1 Borosilicate Glass Powder Funnels8-cm diameterfunnels with 1-cm int
16、ernal diameter and stems about 3.5 cmlong. Tips of funnels should be cut at a right (not oblique)angles (see Fig. 1). The distance between the tip of the upperfunnel and the bottom of the vibrating bowl should be around6 mm.6.7.2 Electromagnetic JoggerWith approximately 175-by 250-mm deck, and shall
17、 be capable of vibrating at afrequency of 60 Hz.6.7.3 Acrylic ClampTo hold cylinder.6.7.4 Vibrating BowlHaving a diameter of approximately7.5 cm and a height of 4.0 mm, such as that being used withrotary micro riffler.6.7.5 Displacement Probe and Reading DevicePermittingcontinuous monitoring of ampl
18、itude vibration.6.7.6 Graduated Cylinder50 mL, with inside diameterapproximately 23 mm and height approximately 19 cm.6.7.7 Photoelectric Sensor Switch.6.7.8 Control DevicePermitting real-time adjustment ofthe vibration amplitude and automatic stopping of the feedingdevice when the coke level reache
19、s the 50-mL mark.6.7.9 Automatic Timer, Clock, or WatchWith a secondindicator.6.7.10 Line Stabilizer (Optional)Use if the noise on thepower line is significant and affects the apparatus performance.6.7.11 Round Level.6.7.12 Balance0 to 300 g and sensitive to 0.01 g.7. Hazards7.1 Exercise care in the
20、 operation of the roll crusher.7.1.1 Wear safety glasses and keep hands clear when feed-ing material.7.1.2 Turn power off at the source when equipment isopened for cleaning after the grinding operation.8. Sample Preparation8.1 Reduce the original sample volume to about 1 kg.8.2 Manually screen out t
21、he natural to 4.75 by 1.18 mm and0.85-mm fraction.8.8 Adjust the roller spacing to 0.5 mm and grind the 0.85-mm fraction. Manually screen out the 0.85 by0.425-mm fraction and add this fraction into the same plasticbag referred to in 8.7. Discard the 0.85-mm fraction, if present.FIG. 1 Example of Sem
22、i-Automated Apparatus Set-UpD74540828.9 Repeat, if necessary, the grinding procedure in 8.8 of the 0.85-mm fraction, until all particles pass through the0.85-mm sieve. It is possible that at this step, about 1 to3gofparticles larger than 0.85 mm cannot be ground to finerparticles. Do not attempt to
23、grind them using roller spacingsmaller than 0.5 mm. Simply discard them (these particles arein general, plate-like shape particles and should not be used forbulk density measurement).8.10 Manually mix the contents of the plastic bag.8.11 Divide the 0.85 by 0.425-mm material between twosets of sieves
24、 with openings of 0.85 mm and 0.425 mm andtheir pan. Using a sieving shaker screen out the 0.85 by0.425-mm fraction for 7 min. Discard the 0.425 mm material.8.12 Transfer the 0.85 by 0.425-mm material into an appro-priate plastic container and manually mix the contents (about100 mL of material is ne
25、eded for analysis).9. Preparation of Apparatus9.1 Install the apparatus as shown Fig. 1.10. Calibration and Standardization10.1 Calibration of Graduated CylinderAdjust the heightof the photodetector, and determine the true volume at the50-mL mark of the graduated cylinder, following the detailedproc
26、edure given in Annex A2. Calibration shall be made eachtime a new cylinder is used or when the apparatus is moved.10.2 Determination of the Displacement Speed Target of theJoggerDetermine the displacement target, in accordancewith Annex A3, using standard reference materials. Onceestablished, this t
27、arget shall be kept indefinitely unless theprobe, the controller or the jogger have to be changed.10.3 Feeding RateCheck/adjust the feeding rate for eachsample.11. Procedure11.1 Make sure that the vibrating table is levelled.11.2 Turn on the apparatus at least 10 min before initiatingmeasurements. T
28、he power should not be turned off betweenreadings.11.3 Weigh the graduated cylinder to the nearest 0.01 g,insert it into the clamping device on the vibrating table whileensuring it does not touch the photoelectric sensor, and let thetable vibration stabilize to the set points (it takes a fewseconds)
29、.11.4 Fill the upper funnel with the coke sample.11.5 Fill the cylinder to about half, using maximum feedingrate, to make a constant bed in the vibrator bowl. Stop thefeeding, empty the cylinder in the upper funnel, and reinsert itin the clamping device.11.6 Using the automatic mode, reset the chron
30、ometer,initiate the feeding and adjust if necessary, the bowl vibrationintensity to obtain the feeding time of 30 6 3 s/10 mL. Thefeeding will automatically stop when the 50-mL mark isreached. If no feeding time adjustment was necessary and if thedischarge time falls within 135 and 165 s, proceed to
31、 11.7.Otherwise, repeat 11.6 until the time target is met.11.7 Empty the cylinder in the upper funnel, reinsert it intothe clamping device, and let the table vibration stabilize to theset points (it takes few seconds). Then, using the automaticmode, reset the chronometer and initiate feeding. The fe
32、edingwill stop automatically.11.8 Check that the discharge time falls within 135 and165 s (150 6 15 s). If not, return the coke to the upper funneland repeat from 11.6 to readjust the feeding time.11.9 Remove the cylinder containing the coke and weigh tothe nearest 0.01 g. Take two additional readin
33、gs according to11.7, readjusting, if necessary, the feeding time to meet thetarget (between 135 and 165 s).11.10 If the difference between the lowest and highestweight readings exceeds 0.40 g, check if the apparatus isproperly functioning, and repeat the test until two consecutiveruns agree within t
34、he specified 0.40 g. Discard readings only ifa malfunction was identified (for example, the apparatus wasnot on speed displacement target, or the time target was notmet).12. Calculation or Interpretation of Results12.1 Calculate the average of all acceptable weight readings(at least three).12.2 Calc
35、ulate VBD using the following equation:Vibrated Bulk Density g/mL!5Average weight of coke g!Calibrated volume of cylinder mL!(1)13. Report13.1 Report the average of the readings to the nearest0.001 g/mL.14. Precision and Bias14.1 PrecisionThe repeatability standard deviation hasbeen determined to be
36、 0.0036 g/mL by making eight indepen-dent determinations (0.864, 0.860, 0.854, 0.859, 0.864, 0.859,0.864, 0.863 g/mL) for a same sample within a very shortperiod of time. The reproducibility of this test method will bemade available on or before December 2009.14.2 BiasThis test method is empirical;
37、no statement as tobias is made.15. Keywords15.1 calcined petroleum coke; porosity; vibrated bulkdensityD7454083ANNEXES(Mandatory Information)A1. OTHER SIEVE FRACTIONS USED IN THE ALUMINUM INDUSTRY TO DETERMINED VIBRATED BULK DENSITYA1.1 Froma2kgas-received sample, split the test samplewith a riffle
38、sampler to a subsample of 350 6 50 g.A1.2 Sieve the subsample to collect the as-received particlefraction to be measured in accordance with TableA1.1. Discardthe undersized particle fraction.A1.3 Taking care to avoid overcrushing, crush the over-sized fraction of the subsample in a jaw crusher (of t
39、helaboratory type, having manganese steel jaws capable of beingset to gaps of approximately 3 to 15 mm) or roll crusher, andplace the material between the appropriate two sieves with apan on the bottom and a lid on the top. Gently agitate the sievesby hand but vigorously enough to collect the crushe
40、d particlefraction to be measured and discard the undersized material.Repeat until at least 90 % (and preferably more) of thesubsample passes through the upper size sieve for the particlefraction to be measured.A1.4 Mix the as-received and crushed particle fractions. Aminimum of 110 g of sieved, cru
41、shed and mixed particles arerequired for the VBD test. The mixed sample is sieved for 10min in a sieve shaker. Discard undersized material.A2. ADJUSTMENT OF THE PHOTOELECTRIC SENSOR HEIGHT AND GRADUATED CYLINDER CALIBRATIONA2.1 Ensure that the table is level, and turn the apparatuson.A2.2 Insert the
42、 cylinder into the clamping device of theVBD apparatus while ensuring it does not touch the photoelec-tric sensor.A2.3 Fill the upper funnel with a typical coke sample.A2.4 Make sure the electromagnetic jogger is turned on, fillthe cylinder approximately up to the 45-mL line using maxi-mum feeding r
43、ate, and stop the feeding.A2.5 Using the automatic mode, alternately start and stopthe feeding whenever necessary to bring the coke level to thedesired position (should be the 50-mL line of the cylinder).A2.6 Bring the photoelectric sensor very slightly above thedesired position by sliding the brack
44、et (the knob should beunscrewed) while holding the sensor (do not forget to screw theknob afterward).A2.7 Set the vibrating bowl control to OFF to avoidfeeding. Reset the chronometer, press START to get thechronometer running, and adjust the photoelectric sensorheight very slowly until it stops the
45、chronometer.A2.8 Remove the cylinder, transfer the coke back into theupper funnel and reinsert it into the clamping device. Using theautomatic mode, reset the chronometer and press start thefeeding. The feeding will automatically be stopped by thephotoelectric sensor. If necessary, make a fine readj
46、ustment ofthe height of the sensor. Repeat A2.8 until the desired positionis reached (should be the 50-mL line).A2.9 Once the photoelectric sensor is at the desiredposition, empty the vibrating bowl.A2.10 Set the vibrating bowl control to OFF.A2.11 Make sure the electromagnetic jogger is turned OFF.
47、A2.12 Clean the graduated cylinder, and tare it.A2.13 Fill the cylinder approximately up to the 48-mL linewith distilled water equilibrated to room temperature. Makesure no drops stick to the wall of the cylinder.A2.14 Insert the cylinder into the clamping device.A2.15 Reset the chronometer to zero.
48、A2.16 Start the automatic controller and add distillate waterdrop-wise until the photoelectric sensor stops the chronometer(a “click” is then heard). Make sure no drops stick to the wallof the cylinder and the meniscus is flat. (If the meniscus is notflat, the cylinder may not be clean enough. Rejec
49、t this test,empty the cylinder, and repeat from A2.12.A2.17 Remove the cylinder from the clamping device andweigh it.A2.18 Measure the water temperature in the cylinder.A2.19 Empty the cylinder.A2.20 Repeat A2.14 to A2.19 nine other times; record theweight of water each time.TABLE A1.1 Sieve FractionsTypes of Coke Nominal Width ofSmaller ScreenOpening (mm)Nominal Width ofBigger ScreenOpening (mm)Coke for prebaked anodes 0.25 0.5Coke for Sderberg anodes 1 2Coke for cathode blocks 2 4D7454084A2.21 Using the appropriate water density (see TableA2.1), calcul
