1、Designation: D2867 09 (Reapproved 2014)D2867 17Standard Test Methods forMoisture in Activated Carbon1This standard is issued under the fixed designation D2867; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 These test methods provide threetwo procedu
3、res for the determination of the moisture content of activated carbon.2 Theprocedures may also be used to dry samples required for other tests. The oven-drying and moisture balance methods are ovendrying method is used when water is the only volatile material present and is in significant quantities
4、, and the activated carbon isnot heat-sensitive heat sensitive (some activated carbons can ignite spontaneously at temperatures as low as 150C).150 C). Thexylene-extraction xylene extraction method is used when a carbon is known or suspected to be heat sensitive or to containnonwater-miscible organi
5、c compounds instead of or in addition to water. The oven-drying oven drying method described in thesetest methods may be used as the reference for development of instrumental techniques for moisture determination in activatedcarbon.1.2 The values stated in SI units are to be regarded as standard. No
6、 other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicabili
7、ty of regulatorylimitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Tr
8、ade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3E177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Summary of Test Method
9、s3.1 Oven-Drying Oven Drying Test MethodA sample of carbon is put into a dry, closed capsule (of known weight) andweighed accurately. The capsule is opened and placed with the lid in a preheated oven. The sample is dried to constant weight thenremoved from the oven and with the capsule closed, coole
10、d to ambient temperature. The closed capsule is weighed againaccurately. The weight loss is expressed as a percentage of the weight of the original sample.3.2 Xylene-Extraction Xylene Extraction Test MethodAknown, accurate weight of carbon is put into a boiling flask.Aknownvolume of xylene is added
11、to the flask and the flask is then connected to a water trap. A hot plate is used to heat the xylene untilboiling. The temperature is controlled to allow steady reflux. Reflux continues until no further water can be collected in the trap.The weight of water collected is expressed as a percentage of
12、the weight of the original sample.3.3 Moisture Balance Test MethodA sample of activated carbon is placed in a moisture balance and the weight measuredaccurately. The sample is dried to constant weight. The weight loss is expressed as a percentage of the weight of the originalsample.1 These test meth
13、ods are under the jurisdiction of ASTM Committee D28 on Activated Carbon and are the direct responsibility of Subcommittee D28.04 on Gas PhaseEvaluation Tests.Current edition approved July 1, 2014July 1, 2017. Published September 2014July 2017. Originally approved in 1970. Last previous edition appr
14、oved in 20092014 asD2867 09.D2867 09 (2014). DOI: 10.1520/D2867-09R14.10.1520/D2867-17.2 The moisture balance method has been used in industry when water is the only volatile material present and is in significant quantities and when the activated carbonis not heat sensitive.Aprecision and bias stat
15、ement for the moisture balance method has not been developed byASTM.Values obtained using this technique should be properlycorrelated to one of the documented methods described in this standard.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at se
16、rviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version
17、. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International,
18、 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Significance and Use4.1 The moisture content of activated carbon is often required to define and express its properties in relation to the net weightof the carbon.4.2 The moisture content of activated carbon pack
19、ed in typical shipping containers will usually increase during transportationand storage. Users of activated carbon in applications where low moisture content is important should be aware of this effect.OVEN-DRYING OVEN DRYING METHOD5. Apparatus5.1 Moisture OvenMost commercial, electrically heated,f
20、orced-circulation drying ovens capable of temperature regulation between 145 and 155C155 C may be used.5.2 Capsules with CoversLow-form glass weighing bottles with ground-glass stoppers or seamless metal boxes with coversmay be used. They should be as shallow as possible, consistent with convenient
21、handling.5.3 Desiccator.6. Materials6.1 DesiccantAnhydrous calcium chloride or other suitable desiccant.7. Procedure for Activated Carbon Passing Aa No. 50 Sieve7.1 Dip out with a spoon or spatula from the sample bottle a 11- to 2-g representative sample. Put this into a predried taredcapsule with l
22、id, close and weigh at once to the nearest 0.5 mg. The depth of the carbon in the capsule must not exceed 1.25 cm.1.25 cm.7.2 Remove the cover and place the capsule and cover in a preheated forced circulation forced-circulation oven (at 145 to155C).155 C). Close the oven and dry to constant weight (
23、3 h normally sufficient). Open the oven and cover the capsules quickly.Cool in a desiccator to ambient temperature and weigh.8. Procedure for Activated Carbon Larger Than Aa No. 50 Sieve8.1 Use a 55- to 10-g representative sample and weigh to the nearest 2 mg. Complete the determination as described
24、 in Section7.9. Calculation9.1 Calculate the moisture content as follows:Moisture,weight%5C 2D!/C 2B!# 3100where: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 XYLENE EXTRACTION M
25、ETHOD10. Apparatus10.1 Boiling FlaskA 300-mL flat-bottom Erlenmeyer flask with ground-glass joints.10.2 CondenserA 300-mm water-cooled condenser of the Allihn type with ground-glass joints.10.3 Drying Tube, containing a suitable desiccant with fiber-glassfiberglass filter.10.4 Water TrapA Bidwell an
26、d Sterling 10-mL or a Dean and Stark receiver with ground-glass joints. The water trap shouldbe clean so that the shape of the meniscus at the end of the test is the same as at the beginning.NOTE 1The trap may be coated with a silicone resin to give a uniform meniscus. To coat the trap, first clean
27、it with a suitable cleaner. Rinse the cleantrap with a silicone resin and after draining for a few minutes, bake for 1 h at approximately 200C.200 C.10.5 Hot PlateAn electrically heated hot plate with enclosed elements and temperature control.D2867 17211. Reagent11.1 XyleneReagent grade Reagent-grad
28、e in accordance with the specifications of the Committee on Analytical Reagents ofthe American Chemical Society.412. Hazards12.1 The use of hot xylene presents a continual fire hazard and suitable fire extinguishing equipment should be available.13. Preparation of Apparatus13.1 Clean the condenser,
29、flask, and trap and carefully dry to ensure that it is free of water. Assemble the condenser and watertrap as shown in Fig. 1.4 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American
30、 Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville, MD.FIG. 1 Moisture Determination ApparatusD2867 17314. Procedure14.1 Weigh the sample bot
31、tle. Dip out with a spoon from the sample bottle 25 to 50 g of the sample. Put this into the boilingflask and reweigh the sample bottle to the nearest 0.1 g. Add 100 mL of xylene and connect the boiling flask to the water trap.For carbons having density less than 0.30 g/cm g/cm3, 200 mL of xylene sh
32、ould be used for a 25-g sample.14.2 Place the hot plate under the boiling flask and heat to boiling. Adjust the temperature control so as to reflux the xylene atthe rate of about 1 drop/s from the tip of the condenser. Continue to reflux until there is no further increase in the water layer inthe tr
33、ap over a 30-min period (from 2 to 8 h may be required).15. Calculation15.1 Calculate the moisture content as follows:Moisture,weight%5V/C 2E!# 3100where:V = water collected, mL,C = initial weight of sample bottle, g, andE = weight of sample bottle after removing moisture sample, g.15.2 Calculate fo
34、r the correction for moisture in carbon to determine the weight of a carbon sample on the dry basis as follows:Corrected weight dry basis!5 (1)Initial weight of Carbonundried!3100%2%moisture from 15.1!100%!MOISTURE BALANCE METHOD16. Apparatus16.1 Moisture balance, having a sensitivity of 0.1 mg and
35、preferably an indirect heating source.NOTE 2An indirect heating source is preferred due to the very strong absorption of infrared radiation by activated carbon and the resulting temperatureincrease to values higher than that of the surrounding atmosphere.17. Procedure for Activated Carbon Passing a
36、No. 50 Sieve.17.1 Set up the moisture balance according to the manufacturers instructions. The temperature should not exceed 150C.D2867 17417.2 Place a representative sample of about 1 to 2-g into the moisture balance and determine its weight to the nearest 0.1 mg.17.3 Close the lid and start the ma
37、chine.17.4 Once the weight loss under these drying conditions is less than 1 mg over 30 s, the sample is considered dry and the percentmass loss should be recorded to the nearest 0.1 %.18. Procedure for Activated Carbon Larger Than a No. 50 Sieve18.1 Set up the moisture balance according to the manu
38、facturers instructions. The temperature should not exceed 150C.18.2 Place a representative sample of about 5 to 10-g into the moisture balance and determine its weight to the nearest 0.1 mg.18.3 Complete the determination as described in Section 17.19. Calculation19.1 Calculate the moisture content
39、as follows:Moisture,weight %5A 2B!/A# 3100where:A = weight of sample before heating, gB = weight of sample after heating, g16. Precision and Bias16.1 An interlaboratory test which included four laboratories testing in triplicate, and activated carbon samples with nominalmoisture levels of 1 weight %
40、, 5 weight %, and 12 weight %, was conducted according to Practice E691. Results of these testsyielded repeatability and reproducibility coefficients at 95 % confidence levels as listed in Table 1.16.1.1 The high coefficients of variation for both test methods when the moisture is nominally 1 weight
41、 % suggests that valuesin this range be reported as “1 weight % or less.” If greater precision is needed, the amount of carbon sample can be increasedover that specified in Sections 7, 8, and 14.20.2 No precision and bias statement has been developed on the moisture balance method; however, it is an
42、ticipated that it willbe developed.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 standard are expressly advised that determination of the valid
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46、ies) 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, 22
47、2Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 1 Within- and Between-Laboratory PrecisionNominal Moisture, weight % 1 5 12Oven Drying MethodRepeatability Coefficient, CV %rA 19 3 6Reproducibility Coefficient, CV %RA 51 13 10Xylene Extraction MethodRepeatability Coefficient, CV %rA 51 5 6Reproducibility Coefficient, CV %RA 54 6 6A Defined in Practice E177, Section 28.D2867 175
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