1、Designation: E 887 88 (Reapproved 2009)Standard Test Method forSilica in Refuse-Derived Fuel (RDF) and RDF Ash1This standard is issued under the fixed designation E 887; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l
2、ast 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 silica inRDF, RDF ash, fly ash, bottom ash, or slag.1.2 The test method is
3、 an acid dehydration gravimetricprocedure and is independent of interferences.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with
4、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. For hazard state-ment, see Section 6.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagen
5、t WaterE 791 Test Method for Calculating Refuse-Derived FuelAnalysis Data from As-Determined to Different BasesE 829 Practice for Preparing Refuse-Derived Fuel (RDF)Laboratory Samples for Analysis33. Summary of Test Method3.1 Silicon compounds in RDF ash, fly ash, bottom ash, orslag are dissolved by
6、 alkali fusion and dehydrated withhydrochloric acid (HCl). Dehydration is completed by ignition,and the silica is volatilized as silicon tetrafluoride.4. Apparatus4.1 Analytical Balance, capable of weighing to 0.0001 g.4.2 Muffle FurnaceThe furnace shall have an operatingtemperature of up to 1200C.4
7、.3 Hot Plate or Steam Bath.4.4 Platinum Crucibles, 35 to 85-mL capacity.4.5 Graphite Crucibles, 35 to 85-mL capacity.4.6 Fused Quartz Dishes, 35 to 85-mL capacity.5. Reagents and Materials5.1 Purity of ReagentsReagent grade chemicals shall beused in this test. Unless otherwise indicated, it is inten
8、ded thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Societywhere such specifications are available.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use withou
9、t lessening theaccuracy of the determination.5.2 Purity of WaterUnless otherwise indicated, referenceto water shall be understood to mean at least Type III reagentwater conforming to Specification D 1193.5.3 Sodium Carbonate (Na2CO3), anhydrous powder.5.4 Hydrochloric Acid (HCl), concentrated, sp gr
10、 1.19.5.5 Hydrochloric Acid (1 + 3), Mix 1 volume of concen-trated HCl with 3 volumes of water.5.6 Hydrochloric Acid (1 + 1)Mix 1 volume of concen-trated HCl with 1 volume of water.5.7 Hydrochloric Acid (1 + 99)Mix 1 volume of concen-trated HCl with 99 volumes of water.5.8 Sulfuric Acid (1 + 1)Mix 1
11、 volume of concentratedsulfuric acid (H2SO4, sp gr 1.84) with 1 volume of water.5.9 Hydrofluric Acid (HF), concentrated 48 to 51 %.6. Hazards6.1 Due to the origins of RDF in municipal waste, commonsense dictates that precautions should be observed whenconducting tests on the samples. Recommended hyg
12、ienicpractices include use of gloves when handling RDF; wearingdust masks (NIOSH-approved type), especially while millingRDF samples; conducting tests under negative pressure hoodswhen possible; and washing hands before eating or smoking.1This test method is under the jurisdiction of ASTM Committee
13、D34 on WasteManagement and is the direct responsibility of Subcommittee D34.03.02 onMunicipal Recovery and Reuse (Disbanded 06/09).Current edition approved July 1, 2009. Published August 2009. Originallyapproved in 1982. Last previous edition approved in 2004 as E 887 88 (2004).2For referenced ASTM
14、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.3Withdrawn. The last approved version of this historical standard is referencedon
15、www.astm.org.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United Stat
16、es Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Sampling7.1 Refuse-Derived Fuel (RDF):NOTE 1ASTM Subcommittee E38.01 is currently in t
17、he process ofdeveloping procedures for sampling RDF.7.1.1 RDF products are frequently nonhomogeneous. Forthis reason, significant care should be exercised to obtain arepresentative laboratory sample from the RDF lot to becharacterized.7.1.2 The sampling method for these procedures should bebased on
18、agreement between involved parties.7.1.3 The laboratory sample must be air-dried and particlesize reduced to pass a 0.5-mm screen for analysis. Thisprocedure must be performed carefully to preserve the sam-ples representative characteristics (other than particle size)while preparing the analysis sam
19、ple to be used in this proce-dure (see Practice E 829).7.2 Refuse-Derived Fuel Ash, Fly Ash, Bottom Ash, orSlagThe method of sampling for this procedure should bebased on agreement between involved parties.8. Sample Preparation8.1 Refuse-Derived Fuel:8.1.1 Weigh accurately 30 to 50 g of RDF analysis
20、 sampleas prepared in 6.1 into a conditioned and preweighed fusedquartz dish.8.1.2 Spread out the analysis sample of RDF in a layer notover 38.1 mm (112 in.) in depth.8.1.3 Place the dish in the muffle at a low temperature (notgreater than 100C) and gradually heat to redness at such a rateas to avoi
21、d mechanical loss from too rapid expulsion of volatilematter.8.1.4 Complete the conversion to ash at a temperature of800 to 900C (1470 to 1650F).8.1.5 Cool in a desiccator and stir the ash to ensurehomogeneity of particle sizes. Be careful not to lose any ashfrom the dish during this stirring.8.1.6
22、Spread the ash in a thin layer in the dish, and ignite ina stream of oxygen for 112 h at 800 to 850C (1470 to 1560F)to ensure complete and uniform oxidation of the ash.8.1.7 Cool the ash to room temperature in a desiccator.8.1.8 Weigh the dish and the ash.8.1.9 Calculate the percent ash as follows:%
23、 Ash 5 C 2 A!/B 2 A! 3 100 (1)where:A = weight of fused quartz, g,B = weight of fused quartz dish and sample, g, andC = weight of fused quartz dish and ash, g.8.2 Refuse-Derived Fuel Ash, Fly Ash, Bottom Ash, or Slag:8.2.1 Prepare the RDF ash, fly ash, bottom ash, or slag bygrinding the sample in an
24、 agate mortar to a particle size to passa No. 200 (75-m) sieve.8.2.2 Weigh accurately 6 to 10 g of RDF ash, fly ash, bottomash, or slag as prepared in 8.2.1 into a conditioned preweighedfused quartz dish.8.2.3 Spread out the analysis sample of the ash to beanalyzed in a layer not over 6.4 mm (14 in.
25、) in depth.8.2.4 Place the dish in the muffle at a low temperature (notgreater than 100C), and gradually heat to redness at such arate as to avoid mechanical loss from too rapid expulsion ofvolatile matter.8.2.5 Complete the conversion to ash at a temperature of800 to 900C (1470 to 1659F).8.2.6 Cool
26、 in a desiccator and stir the ash to ensurehomogeneity of particle sizes. Be careful not to lose any ashfrom the dish during this stirring.8.2.7 Spread the ash in a thin layer in the dish and ignite ina stream of oxygen for 112 h at 800 to 850C (1470 to 1560F)to ensure complete and uniform oxidation
27、 of the ash.8.2.8 Cool the ash to room temperature in a desiccator.8.2.9 Weigh the dish and the ash.8.2.10 Calculate the percent residue after ignition as fol-lows:% Residue after ignition 5 F 2 D!/E 2 D! 3 100 (2)where:D = weight of fused quartz dish, g,E = weight of fused quartz dish and sample, o
28、f RDF ash,fly ash, bottom ash or slag, g, andF = weight of fused quartz dish and residue after ignition ofRDF ash, fly ash, bottom ash, or slag, g.9. Procedure9.1 Sample Fusion:9.1.1 Weigh accurately 0.010 to 0.100 g of the preparedRDF ash as prepared in 8.1 or the residue of RDF ash, fly ash,bottom
29、 ash, or slag as prepared in 8.2 into a platinum orgraphite crucible.9.1.2 Add 1.0 g of Na2CO3. Mix the ash and Na2CO3well,then add an additional 0.5 g of Na2CO3to cover the mixture.9.1.3 Place the crucible into a clean silica or refractory tray,and place in a muffle furnace preheated to 1000C and m
30、aintainuntil the mass is quiescent (about 45 min).9.1.4 Set the crucible aside to cool.9.1.5 Rinse off the outside of the crucible, and place it on itsside in a 300-mL casserole or beaker about one-third full ofwater. Warm and stir until the cake disintegrates and can beeasily removed.9.1.6 By means
31、 of platinum tipped tongs, lift the crucibleout of the liquid, rinsing it thoroughly with water followed byrinsing with dilute hydrochloric acid (HCl, 1 + 3); adding therinse to the casserole or beaker.9.2 Acid Dehydration:9.2.1 Very slowly and cautiously add 20 mL of concentratedhydrochloric acid (
32、HCl, sp gr 1.19) to the covered casserole orbeaker (see Note 2). Remove the cover and rinse. If any grittyparticles are present, the fusion is incomplete and must berepeated, using a new sample and a larger amount of Na2CO3.NOTE 2This solution will tend to “creep” over the rim of the casseroleunless
33、 the rim is kept hot and dry. This can be accomplished by applyingheat from above by means of infrared lamps.9.2.2 Evaporate the solution to dryness on a steam bath.9.2.3 Without heating the residue any further, treat it with 5to 10 mL of HCl (concentrated), wait at least 2 min, then addan equal amo
34、unt of water.E 887 88 (2009)29.2.4 Cover the casserole or beaker, and digest for 10 minon the steam bath or hot plate.9.2.5 Dilute the solution with an equal volume of hot water,immediately filter through medium-textured ashless paper, andwash the residue thoroughly with hot HCl (1 + 99), then withh
35、ot water.9.2.6 Reserve the residue.9.2.7 Again, evaporate the filtrate to dryness and bake theresidue in an oven for1hat105to110C.9.2.8 Cool, add 10 to 15 mL HCl (1 + 1) and digest on thesteam bath or hot plate for 10 min.9.2.9 Dilute with an equal volume of water, filter immedi-ately on a fresh fil
36、ter paper, and wash the small amount ofresidue thoroughly with hot HCl (1 + 99), then with hot water.9.2.10 Transfer the papers containing the residues (from9.2.6 and 9.2.9) to a weighed conditioned platinum crucible.9.2.11 Dry and ignite the papers, first at a low heat until thecarbon of the filter
37、 paper is completely consumed withoutflaming, and finally ignite at 1100 to 1200C until the weightbecomes constant. Record weight of residue after ignition.9.3 Volatilization of Silicon Tetrafluoride:9.3.1 Treat the silica (SiO2) thus obtained, which will con-tain impurities, in the crucible with 0.
38、5 to 1 mL of water, 2drops of H2SO4(1 + 1) and 10 mL of HF.9.3.2 Cautiously evaporate to dryness on a hot plate or hotsand bath.9.3.3 Finally, ignite the small residue at 1050 to 1100C(1922 to 2012F) for 5 min.9.3.4 Cool in a desiccator and weigh.9.3.5 The difference between this weight and the weig
39、htpreviously obtained in 9.2.11 represents the amount of SiO2.9.4 BlankMake a blank determination, following thesame procedures as used in 9.1.2 through 9.3.5 using the sameamounts of reagents and correct the obtained in the analysisaccordingly.10. Calculation10.1 Calculate the concentration of SiO2
40、as follows:10.1.1 Percent SiO2on prepared sample as used in 9.1.1.% SiO25 W12 W2! 2 W32 W4!/W53 100 (3)where:W1= weight of residue after first ignition as in 9.2.11,g,W2= weight of blank after first ignition, g,W3= weight of residue after treatment with HF and secondignition as in 9.3.4,g,W4= weight
41、 of blank after treatment with HF and secondignition, g, andW5= weight of sample of prepared RDF, RDF ash, fly ash,bottom ash, or slag as used in 9.1.1,g.10.1.2 Percent SiO2in RDF (6.1).% SiO2in RDF 5 G 3 H!/100! (4)where:G = ash as found in 8.1.9, %, andH = SiO2as found in 10.1.1,%.10.1.3 Percent S
42、iO2in RDF ash, fly ash, bottom ash, or slag(8.2).% SiO2in RDF Ash, fly ash, bottom ash, or slag 5 I 3 H!/100!(5)where:I = residue after ignition as found in 8.2.10, %, andH = SiO2as found in 10.1.1,%.See Method E 791 for procedures to convert values to otherbases.11. Precision and Bias11.1 Precision
43、 and bias statements cannot be made at thistime for the measurement of SiO2by this test method.ASTM 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 determina
44、tion 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 years andif not revised, either reapproved or with
45、drawn. 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 committee, which you may attend. If you feel that you
46、r 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 19428-2959,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).E 887 88 (2009)3
