1、Designation: D4931 06 (Reapproved 2011)Standard Test Method forGross Moisture in Green Petroleum Coke1This standard is issued under the fixed designation D4931; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. 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 both the preparation procedurefor samples containing free water (air drying loss (ADL) ongross moisture
3、samples) and the determination of the grossmoisture content of green petroleum coke.1.2 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated wit
4、h 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. Referenced Documents2.1 ASTM Standards:2D2013 Practice for Preparing Coal Samples for AnalysisD2234/D2234M
5、Practice for Collection of a Gross Sampleof CoalD3302 Test Method for Total Moisture in CoalE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 air drying, na process of partial drying of a greenpetroleum coke sample
6、to bring it to near equilibrium with theatmosphere in the room in which further reduction/division ofthe petroleum coke sample is to take place.3.1.2 air dry loss, ADL, nthe loss in mass, expressed as apercentage, resulting from each air drying operation.3.1.3 free water, nvisible unbound water in t
7、he sample.3.1.4 green petroleum coke, nsame as raw petroleumcoke.3.1.5 gross moisture, nthat moisture determined as theloss in mass in an air atmosphere under rigidly controlledconditions of temperature, time, and air flow.3.1.5.1 DiscussionTest Method D3302 prescribes theabove controlled conditions
8、.3.1.6 petroleum coke, nsolid, carbonaceous residue pro-duced by thermal decomposition of heavy petroleum fractions,or cracked stocks, or both.3.1.7 residual moisture, nthat moisture remaining in thesample after air drying.3.1.8 total moisture, nsynonym for gross moisture.4. Summary of Test Method4.
9、1 This test method is based on the loss in mass of a greenpetroleum coke sample in an air atmosphere under controlledconditions of temperature, time, and air flow.4.1.1 Preparation Procedure shall be used when the petro-leum coke sample contains free water. The gross moisturesample is weighed and ai
10、r dried to equilibrate it with theatmosphere. Determination of residual moisture is that deter-mined using the Drying Oven Method. Air drying and residualmoisture losses are combined to report gross moisture.4.1.2 Drying Oven Method shall be used in routine com-mercial practice when the sample does
11、not contain free water.The sample is crushed to at least minus 25 mm (1 in.) top sievesize and divided into analytical portions of at least 500 g each.Determination of total gross moisture is calculated by summingthe results of the Drying Oven Method and the results of thePreparation Procedure.5. Si
12、gnificance and Use5.1 Moisture adds weight to the coke and serves no usefulpurpose. A knowledge of the moisture content is important inthe purchase and sale of green petroleum coke, both of whichare conducted on a dry basis.5.2 The collection of the sample as specified for the DryingOven Method is i
13、ntended for the express purpose of determin-ing the total moisture of green petroleum coke. The standard is1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.05 on Properties of Fuels, Petroleum Co
14、ke and Carbon Material.Current edition approved May 1, 2011. Published August 2011. Originallyapproved in 1989. Last previous edition approved in 2006 as D493106. DOI:10.1520/D4931-06R11.2For 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.available to producers, sellers, and consumers for determin
16、a-tion when other techniques or modifications are not mutuallyagreed on.5.3 The Preparation Procedure is used only when samplecontains free water. Obtaining a representative sample of acoke source is compounded by the presence of free water.6. Apparatus6.1 Ovens:6.1.1 Air Drying OvenA device for pas
17、sing slightlyheated air over the sample. The oven shall be capable ofmaintaining a temperature of 10 to 15C (18 to 27F) aboveambient with a maximum oven temperature of 40C (104F)unless ambient temperature is above 40C (104F), in whichcase ambient temperature shall be used. Air changes are to beat th
18、e rate of 1 to 4/min. A typical oven is shown in Fig. 1.6.1.2 Drying Oven (for residual moisture on minus 25-mm(1.0-in.) samples sieve USAstandardforced-air type). It shallbe capable of maintaining a temperature of 105 6 5C and soconstructed that fresh air is introduced to all parts of the ovento en
19、sure the removal of moisture-laden air. Air flow shall bemaintained at sufficiently low velocity to prevent loss of fineparticles, (for example, one exchange per minute).6.2 Drying Pans:6.2.1 Pans for the gross moisture sample (PreparationProcedure) shall be noncorroding, weight-stable at temperatur
20、eused, and large enough so that the sample can be spread to adepth of not more than twice the diameter of the largestparticles, or not more than 25 mm (1.0 in.) depth for smallercoke. The pan sides shall be 50 to 75 mm (2 to 3 in.) high.6.2.2 Pans for crushed and divided sample shall be noncor-rodin
21、g, weight-stable at temperature used, and large enough sothat the sample can be spread to depth of not more than 50 mm(2 in.). The sides shall be not more than 75 mm (3 in.) high.6.3 Balances:6.3.1 Balance (Gross Sample)A balance with a minimumcapacity of 10 kg and sensitive to 1 g.6.3.2 Balance (Cr
22、ushed Sample)A balance with a mini-mum capacity of 4 or sufficient to weigh the pan, sample, andcontainer and sensitive to 0.1 g.6.4 Laboratory Sample ContainersNoncorroding canswith airtight, friction top or screw top sealed with a rubbergasket and pressure-sensitive tape for use in storage andtran
23、sport of the laboratory sample. Glass containers, sealedwith rubber gaskets, can be used, but care must be taken toavoid breakage in transport.6.5 SievesMeeting Specification E11.7. Sampling7.1 The principles, terms, and procedures as set forth inPractice D2234/D2234M shall apply to the collection o
24、f thetotal moisture sample. Particular attention is directed to thesection on Sampling Coal for Total Gross Moisture Determi-nation.7.2 Proceed with determination of moisture without unnec-essary delay to minimize the loss (or gain) of moisture to air orthe walls of the sample container. Visible con
25、densation on thewalls of the sample container indicates a moisture loss by thesample. Determine the moisture on the gross sample andinclude the sample container in the drying process adding theweight loss of the container to G (mass of sample) to determinethe total moisture.8. Procedure8.1 Preparati
26、on ProcedureWhen the sample contains freemoisture, a conditioning step is needed before determininggross moisture. If the sample does not contain free water, go to8.2.8.1.1 Distribute the required number of increments of thegross moisture sample in a series of preweighed pans. Thesample is spread to
27、 a depth of not more than 50 mm (2 in.) ortwice the diameter of the largest particle for cokes smaller than25 mm (1.0 in.).8.1.2 Weigh each pan with sample as it is filled from thegross sample and record the weights. Place each in an airdrying oven that has been adjusted to maintain temperature nomo
28、re than 15C (27F) above ambient to a maximum of 40C(104F). Maintain air circulation through oven at a rate of atleast one air exchange per minute, but in no case is it to be sohigh as to blow fine particles from the pans. Gently stir thesample occasionally to ensure uniform drying.FIG. 1 Air Drying
29、OvenD4931 06 (2011)28.1.3 When the coke surfaces appear dry, remove thesample pans from the oven, cool to ambient, weigh, and recordmass to the nearest gram. Return the pans with sample to theoven and repeat the drying and weighing at two hour intervalsuntil the weight loss is less than 0.1%/ h.8.1.
30、4 Allow the sample to reach equilibrium with ambienttemperature and humidity before the final air dry weight isrecorded. Avoid excess drying. Calculate the air dry moistureloss as shown in Step 9.1.1.8.1.5 Proceed with sample reduction to at least 25 mm (1in.) and division into minimum 500 g lots in
31、 accordance withthe procedures listed in Practice D2013. Use enclosed equip-ment where possible to minimize moisture change.8.1.6 The crushed and divided sample, 500 g minimum shallremain in an airtight container with minimum unused volumeuntil starting the determination for Residual Moisture onPrep
32、ared Sample.8.2 Residual Moisture on Prepared Sample (Drying OvenMethod):8.2.1 Determine and record the mass of the drying pan andsample container. Transfer the crushed and weighed sample,including sample container and pan, to an oven maintained at105 6 5C. Dry sample to a constant weight (see Note
33、1).NOTE 1Time required to achieve constant weight is estimated to beapproximately 1 h per 100 g of sample. However, do not assume5hissufficient to dry a 500 g sample to constant weight.9. Calculation9.1 Total Moisture:9.1.1 Calculate air dry losses (ADL) as follows:ADL 5 L2 2 L1!/G 3 100 (1)where:AD
34、L = air dry loss, mass %,L1 = mass of sample after air drying,L2 = mass of sample before air drying, andG = mass of gross sample.9.1.2 Calculate the percent residual moisture, R, as followswhen the Air Drying Procedure is used:R 5 L2 2 L1!/G 3 100 (2)where:R = residual moisture,L1 = mass of sample a
35、fter drying,L2 = mass of sample before drying, andG = mass of sample.9.1.3 Calculate the percent total moisture, M, as followswhen the Air Drying Procedure has been used:M 5 R100 2 ADL!/100 1 ADL (3)where:M = total moisture, of sample mass %,ADL = air dry loss, of sample mass %, andR = residual mois
36、ture.9.2 Calculate the percent total moisture, M, as follows whenthe air drying stage is not used:M 5 WL2 2 WL1!/G 3 100 (4)where:M = total moisture, mass %,WL1 = mass of sample after drying,WL2 = mass of sample before drying,G = mass of sample.10. Precision and Bias10.1 PrecisionThe precision of to
37、tal moisture as deter-mined in 9.1.3 by the statistical examination of the interlabo-ratory test results is as follows:10.1.1 RepeatabilityThe difference between successiveresults obtained by the same operator with the same apparatusunder constant operating conditions on identical test materialswoul
38、d, in the long run, in the normal and correct operation ofthe test method, exceed the following values only one case intwenty.Repeatability 5 0.34% (5)10.1.2 ReproducibilityThe difference between two singleand independent results obtained by different operators work-ing in different laboratories on
39、identical material would, in thelong run, exceed the following values only in one case intwenty.Reproducibility 5 0.58 % (6)NOTE 2The values in the statements were determined in a cooperativeprogram following RR:D02-1007.310.2 The precision for ADL moisture as determined by Step8.1 was not determine
40、d in this program. It is believed that therewould be no difference in the precision.10.3 The interlaboratory program included six duplicatepetroleum coke samples with nine laboratories participating.10.4 BiasSince there is no accepted reference material fordetermining the bias for this test method f
41、or measuring thegross moisture in green petroleum coke, no statement on biasis being made.11. Keywords11.1 air drying loss (ADL); free water; green petroleumcoke; residual moisture; total moisture3Filed at ASTM International Headquarters and may be obtained by requestingResearch Report RR:D02-1007.D
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