ASTM D2867-2004 Standard Test Methods for Moisture in Activated Carbon《活性碳湿度的标准试验方法》.pdf

1、Designation: D 2867 04Standard Test Methods forMoisture in Activated Carbon1This standard is issued under the fixed designation D 2867; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parenthe

2、ses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 These test methods provide two procedures for thedetermination of the m

3、oisture content of activated carbon. Theprocedures may also be used to dry samples required for othertests. The oven-drying method is used when water is the onlyvolatile material present and is in significant quantities, and theactivated carbon is not heat-sensitive (some activated carbonscan ignite

4、 spontaneously at temperatures as low as 150C). Thexylene-extraction method is used when a carbon is known orsuspected to be heat sensitive or to contain nonwater-miscibleorganic compounds instead of or in addition to water. Theoven-drying method described in these test methods may beused as the ref

5、erence for development of instrumental tech-niques for moisture determination in activated carbon.1.2 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

6、 practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.

7、Summary of Test Methods3.1 Oven-Drying Test MethodA sample of carbon is putinto a dry, closed capsule (of known weight) and weighedaccurately. The capsule is opened and placed with the lid in apreheated oven. The sample is dried to constant weight thenremoved from the oven and with the capsule close

8、d, cooled toambient temperature. The closed capsule is weighed againaccurately. The weight loss is expressed as a percentage of theweight of the original sample.3.2 Xylene-Extraction Test Method A known, accurateweight of carbon is put into a boiling flask. A known volume ofxylene is added to the fl

9、ask and the flask then connected to awater trap. A hot plate is used to heat the xylene until boiling.The temperature is controlled to allow steady reflux. Refluxcontinues until no further water can be collected in the trap.The weight of water collected is expressed as a percentage ofthe weight of t

10、he original sample.4. Significance and Use4.1 The moisture content of activated carbon is oftenrequired to define and express its properties in relation to thenet weight of the carbon.4.2 The moisture content of activated carbon packed intypical shipping containers will usually increase during trans

11、-portation and storage. Users of activated carbon in applicationswhere low moisture content is important should be aware ofthis effect.OVEN-DRYING METHOD5. Apparatus5.1 Moisture OvenMost commercial, electrically heated,forced-circulation drying ovens capable of temperature regu-lation between 145 an

12、d 155C may be used.5.2 Capsules with CoversLow-form glass weighingbottles with ground-glass stoppers or seamless metal boxeswith covers may be used. They should be as shallow aspossible, consistent with convenient handling.5.3 Desiccator.6. Materials6.1 DesiccantAnhydrous calcium chloride or other s

13、uit-able desiccant.1These test methods are under the jurisdiction of ASTM Committee D28 onActivated Carbon and are the direct responsibility of Subcommittee D28.04 on GasPhase Evaluation Tests.Current edition approved April 1, 2004. Published May 2004. Originallyapproved in 1970. Last previous editi

14、on approved in 1999 as D 2867 99.2For 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 Internationa

15、l, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Procedure for Activated Carbon Passing A No. 50Sieve7.1 Dip out with a spoon or spatula from the sample bottlea 1 to 2-g representative sample. Put this into a predried taredcapsule with lid, close and weigh at

16、 once to the nearest 0.5 mg.The depth of the carbon in the capsule must not exceed 1.25cm.7.2 Remove the cover and place the capsule and cover in apreheated forced circulation oven (at 145 to 155C). Close theoven and dry to constant weight (3 h normally sufficient). Openthe oven and cover the capsul

17、es quickly. Cool in a desiccator toambient temperature and weigh.8. Procedure for Activated Carbon Larger Than A No.50 Sieve8.1 Usea5to10-g representative sample and weigh to thenearest 2 mg. Complete the determination as described inSection 7.9. Calculation9.1 Calculate the moisture content as foll

18、ows:Moisture, weight % 5 C 2 D! / C 2 B!# 3 100where:B = weight of capsule with cover, g,C = weight of capsule with cover plus original sample, g,andD = weight of capsule with cover plus dried sample, g.XYLENEEXTRACTION METHOD10. Apparatus10.1 Boiling FlaskA 300-mL flat-bottom Erlenmeyerflask with g

19、round-glass joints.10.2 CondenserA 300-mm water-cooled condenser of theAllihn type with ground-glass joints.10.3 Drying Tube, containing a suitable desiccant withfiber-glass filter.10.4 Water TrapA Bidwell and Sterling 10-mL or a Deanand Stark receiver with ground-glass joints. The water trapshould

20、be clean so that the shape of the meniscus at the end ofthe test is the same as at the beginning.NOTE 1The trap may be coated with a silicone resin to give a uniformmeniscus. To coat the trap, first clean it with a suitable cleaner. Rinse theclean trap with a silicone resin and after draining for a

21、few minutes, bakefor1hatapproximately 200C.10.5 Hot PlateAn electrically heated hot plate with en-closed elements and temperature control.11. Reagent11.1 XyleneReagent grade in accordance with the speci-fications of the Committee on Analytical Reagents of theAmerican Chemical Society.312. Hazards12.

22、1 The use of hot xylene presents a continual fire hazardand suitable fire extinguishing equipment should be available.13. Preparation of Apparatus13.1 Clean the condenser, flask, and trap and carefully dryto ensure that it is free of water. Assemble the condenser andwater trap as shown in Fig. 1.14.

23、 Procedure14.1 Weigh the sample bottle. Dip out with a spoon from thesample bottle 25 to 50 g of the sample. Put this into the boilingflask and reweigh the sample bottle to the nearest 0.1 g. Add100 mL of xylene and connect the boiling flask to the watertrap. For carbons having density less than 0.3

24、0 g/cm3, 200 mLof xylene should be used for a 25-g sample.14.2 Place the hot plate under the boiling flask and heat toboiling. Adjust the temperature control so as to reflux thexylene at the rate of about 1 drop/s from the tip of thecondenser. Continue to reflux until there is no further increasein

25、the water layer in the trap over a 30-min period (from 2 to8 h may be required).15. Calculation15.1 Calculate the moisture content as follows:Moisture, weight % 5 V / C 2 E!# 3 100where:V = water collected, mL,C = initial weight of sample bottle, g, andE = weight of sample bottle after removing mois

26、turesample, g.15.2 Calculate for the correction for moisture in carbon todetermine the weight of a carbon sample on the dry basis asfollows:Corrected weight dry basis!5 (1)Initial weight of Carbonundried!3100% 2 % moisture from 15.1!100%!3Reagent Chemicals, American Chemical Society Specifications,

27、AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc.

28、 (USPC), Rockville,MD.D 2867 04216. Precision and Bias16.1 An interlaboratory test which included four laborato-ries testing in triplicate, activated carbon samples with nominalmoisture levels of 1 weight %, 5 weight %, and 12 weight %,was conducted according to Practice E 691. Results of thesetests

29、 yielded repeatability and reproducibility coefficients at95 % confidence levels as listed in Table 1.16.1.1 The high coefficients of variation for both testmethods when the moisture is nominally 1 weight % suggeststhat values in this range be reported as “1 weight % or less.” Ifgreater precision is

30、 needed, the amount of carbon sample canbe increased over that specified in Sections 7, 8, and 14.17. Keywords17.1 activated carbon; moistureASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this

31、 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 five year

32、s 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 technical committ

33、ee, 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, PA 19428

34、-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. 1 Moisture Determination ApparatusT

35、ABLE 1 Within- and Between-Laboratory PrecisionNominal Moisture, weight % 1 5 12Oven Drying MethodRepeatability Coefficient, CV %rA19 3 6Reproducibility Coefficient, CV %RA51 13 10Xylene Extraction MethodRepeatability Coefficient, CV %rA51 5 6Reproducibility Coefficient, CV %RA54 6 6ADefined in Practice E 177, Section 28.D 2867 043