1、Designation: E790 15Standard Test Method forResidual Moisture in Refuse-Derived Fuel AnalysisSamples1This standard is issued under the fixed designation E790; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisio
2、n. 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 measurement of residualmoisture in refuse-derived fuel (RDF) analysis samples. It isused to calculate
3、on a dry basis other determinations performedon analysis RDF samples. It is used with air-dry moistureresults to calculate total moisture (Note 1). The total moistureis used to calculate as-received values or other analysesperformed on a sample.NOTE 1In some instances RDF moisture may change during
4、size-reduction steps of the RDF analysis sample preparation procedure. Thismoisture change, unless suitable corrections are made, will affect theaccuracy of the total moisture value as calculated from the air-dry andresidual moisture results.1.2 The values stated in SI units are to be regarded assta
5、ndard. No other units of measurement are included in thisstandard.1.3 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 app
6、lica-bility of regulatory limitations prior to use. For more specificprecautionary information see Section 7.2. Referenced Documents2.1 ASTM Standards:2D3173 Test Method for Moisture in the Analysis Sample ofCoal and CokeD5681 Terminology for Waste and Waste ManagementE180 Practice for Determining t
7、he Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals (Withdrawn 2009)33. Terminology3.1 For definitions of terms used in this test method, refer toTerminology D5681.4. Summary of Test Method4.1 This test method is based on the weight loss of anair-dried analysi
8、s RDF sample under rigidly controlled condi-tions of temperature, time, and air flow.4.2 The total moisture is calculated from the loss or gainupon sample air drying and the residual moisture as determinedby this test method.5. Significance and Use5.1 The procedure in this test method for a sample a
9、sspecified herein is intended for the purpose of determining theresidual moisture present in a RDF analysis sample.5.2 The residual moisture value is used to correct as-determined analysis results such as gross heating value, sulfur,and ash to dry sample basis results.6. Apparatus6.1 Drying Oven:6.1
10、.1 Referee TypeThe oven shall be constructed to have auniform temperature within the specimen chamber, have aminimum excess air volume, and be capable of constanttemperature regulation at 107 6 3C. Provision shall be madefor renewing the preheated air in the oven at the rate of two tofour times the
11、oven air volume a minute, with the intake airdried by passing through a desiccant. An oven similar to theone illustrated in Fig. 1 of Test Method D3173 is suitable.6.1.2 Routine TypeA drying oven of either the mechanicalor natural circulation type which is capable of constant uniformtemperature with
12、in the specimen chamber regulated at 107 63C.NOTE 2Either type of oven may be used for routine determinations.However, the referee-type oven shall be used to resolve differencesbetween determinations.6.2 ContainersSample ash determinations are made usinga porcelain capsule 22 mm in depth and 44 mm i
13、n diameter ora fused silica capsule of similar shape. A well-fitting flataluminum cover is used when ashing samples. Platinum1This test method is under the jurisdiction of ASTM Committee D34 on WasteManagement and is the direct responsibility of Subcommittee D34.03 on Treatment,Recovery and Reuse.Cu
14、rrent edition approved Sept. 1, 2015. Published September 2015. Originallyapproved in 1981. Last previous edition approved in 2008 as E790 08. DOI:10.1520/E0790-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Boo
15、k of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
16、1crucibles or glass capsules with ground-glass caps may also beused. They should be as shallow as possible while remainingconvenient to handle.6.3 Analytical BalanceBalance capable of weighing withan accuracy of 0.1 mg.6.4 Analysis Sample ContainersHeavy (minimum 4 mil),vapor-impervious bags, proper
17、ly sealed; or noncorroding cans,glass jars, or plastic bottles with air-tight sealing covers to storeRDF samples for analysis. Containers shall be checked forsuitability by measuring weight loss or gain of the sample andcontainer stored for 1 week under ambient laboratory condi-tions. The weight los
18、s or gain should be less than 0.5 % of thesample weight stored in the container.7. Precautions7.1 Due to the origins of RDF in municipal waste, precau-tions should be observed when conducting tests on samples.Recommended safety practices include use of suitable gloveswhen handling RDF; wearing dust
19、masks (NIOSH-approvedtype), especially when shredding RDF samples; conductingtests under a negative pressure hood when possible; andwashing hands upon completion of activity and before eatingor smoking.7.2 Sample handling shall be performed by trained person-nel. All operations shall be done as rapi
20、dly as possible to avoidsample moisture changes due to atmospheric exposure.7.3 Since heavy fine particles tend to segregate rapidly inRDF analysis samples, the analyst should exercise care toassure that the analysis sample is well-mixed prior to perform-ing this determination.7.4 When residual mois
21、ture is to be used for the determi-nation of total moisture, special care shall be taken to minimizeany change in sample moisture between the completion of airdrying and analysis for residual moisture. It is recommendedthat the delay between sample preparation and the determina-tion of residual mois
22、ture not exceed 72 h.8. Sampling48.1 RDF products are frequently inhomogeneous. For thisreason, significant care should be exercised to obtain a repre-sentative sample from the RDF lot to be characterized.8.2 The sampling method used to collect samples for thisprocedure should be based on agreement
23、between the involvedparties.8.3 The laboratory sample must be air-dried and particlesize reduced to pass through a 0.5-mm screen for this analysis.This procedure must be performed carefully to preserve thesamples representativeness beyond just particle size whilepreparing the analysis sample to be a
24、nalyzed according to thisprocedure.9. Procedure9.1 Heat the empty containers and covers under the sameconditions under which the sample is to be dried, place thestopper or cover on the container, cool over a desiccant forabout 15 to 20 min, and weigh to 0.1 mg. Mix the sample, ifnecessary, and take
25、out with a spoon or spatula from the samplebottle approximately1gofsample. Put the sample quickly intothe container, cover, and immediately to 0.1 mg.NOTE 3If weighing bottles with air-tight covers are used, it may notbe necessary to preheat the moisture analysis container nor to desiccate itafter d
26、rying.9.2 Remove the cover and place in a desiccator. Quicklyplace the uncovered container into an oven preheated to 107 63C through which is passed a current of dry air. Close theoven at once and heat for 1 hr. Open the oven, remove, coverthe container quickly, and cool to room temperature in adesi
27、ccator over desiccant. Weigh the sample and container assoon as they have cooled to room temperature.10. Calculation (see Note 1)10.1 Calculate the percent residual moisture, R,intheanalysis sample as follows:R 5S 2 BS3100 (1)where:S = grams of analysis sample used, andB = grams of sample after heat
28、ing.10.2 Calculate the percent total moisture in the laboratorysample, as follows:M 5R 100 2 A!1001A (2)where:R = residual moisture, %, andA = air dry loss determined during preparation of theanalysis sample, %.10.3 To convert other parameters determined on the analysissample, such as ash, sulfur, a
29、nd gross calorific value, to a drysample basis, the following equation can be used:Pdry5Pad100!100 2 R(3)where:Pad= parameter, %“ as-determined” on the analysissample,R = residual moisture, % (see 10.1), andPdry= parameter, % expressed on a dry sample basis.11. Precision and Bias11.1 Precision:11.1.
30、1 The standard deviations of individual determinations,in percent absolute are as follows:Typical AverageValueWithinLaboratoriesBetweenLaboratories2.54.5 % 0.15 % 0.50 %4ASTM Subcommittee E38.01 is currently in the process of developingprocedures for sampling RDF and the preparation of an analysis s
31、ample. Thechairman of E38.01 should be contacted for details.E790 15211.1.2 The above precision estimates are based on aninterlaboratory study conducted in accordance to PracticeE180.11.2 BiasThe bias of this test method has not beendetermined due to a lack of an accepted standard referencematerial.
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