1、Designation: E887 88 (Reapproved 2009)E887 15Standard Test Method forSilica in Refuse-Derived Fuel (RDF) and RDF Ash1This standard is issued under the fixed designation E887; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 of last 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 in RDF, refuse-derived fuel (RDF), RDF ash, fly ash, bottom as
3、h, or slag.1.2 The test method is an acid dehydration gravimetric procedure and is independent of interferences.1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.4 This standard does not purport to address all of the safe
4、ty 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 applicability of regulatorylimitations prior to use. For hazard statement, see Section 6.2. Referenced Documents2.1 ASTM Standards
5、:2D1193 Specification for Reagent WaterE791 Test Method for Calculating Refuse-Derived Fuel Analysis Data from As-Determined to Different BasesE829 Practice for Preparing Refuse-Derived Fuel (RDF) Laboratory Samples for Analysis (Withdrawn 2002)33. Summary of Test Method3.1 Silicon compounds in RDF
6、ash, fly ash, bottom ash, or slag are dissolved by alkali fusion and dehydrated with hydrochloricacid (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
7、shall have an operating temperature of up to 1200C.4.3 Hot Plate Plate, Microwave Digester, 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 gra
8、de chemicals shall be used in this test. Unless otherwise indicated, it is intended that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society wheresuch specifications are available.4 Other grades may be used, provided it is first as
9、certained that the reagent is of sufficiently highpurity to permit its use without lessening the accuracy of the determination.1 This test method is under the jurisdiction of ASTM Committee D34 on Waste Management and is the direct responsibility of Subcommittee D34.03 on Treatment,Recovery and Reus
10、e.Current edition approved July 1, 2009Sept. 1, 2015. Published August 2009October 2015. Originally approved in 1982. Last previous edition approved in 20042009 asE 887 88E887 88 (2009). (2004). DOI: 10.1520/E0887-88R09.10.1520/E0887-15.2 For referencedASTM standards, visit theASTM website, www.astm
11、.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.4 Reagent Chemicals, American Chemical
12、 Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Phar
13、macopeial Convention, Inc. (USPC), Rockville, MD.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. Becauseit may not be technically possible to adequately depict all changes accurat
14、ely, 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, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
15、15.2 Purity of WaterUnless otherwise indicated, reference to water shall be understood to mean at least Type III reagent waterconforming to Specification D1193.5.3 Sodium Carbonate (Na2CO3), anhydrous powder.5.4 Hydrochloric Acid (HCl), concentrated, sp gr 1.19.5.5 Hydrochloric Acid (1 + 3),Mix 1 vo
16、lume of concentrated HCl with 3 volumes of water.5.6 Hydrochloric Acid (1 + 1)Mix 1 volume of concentrated HCl with 1 volume of water.5.7 Hydrochloric Acid (1 + 99)Mix 1 volume of concentrated HCl with 99 volumes of water.5.8 Sulfuric Acid (1 + 1)Mix 1 volume of concentrated sulfuric acid (H2SO4, sp
17、 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, common sense dictates that precautions should be observed when conductingtests on the samples. Recommended hygienicsafety practices include use of suitable
18、gloves when handling RDF; wearing dustmasks (NIOSH-approved type), especially while milling RDF samples; conducting tests under negative pressure hoods whenpossible; and washing hands upon completion of activity and before eating or smoking.7. Sampling7.1 Refuse-Derived Fuel (RDF):NOTE 1ASTM Subcomm
19、ittee E38.01 is currently in the process of developing procedures for sampling RDF.7.1.1 RDF products are frequently nonhomogeneous. For this reason, significant care should be exercised to obtain arepresentative laboratory sample from the RDF lot to be characterized.7.1.2 The sampling method for th
20、ese procedures should be based on agreement between involved parties.7.1.3 The laboratory sample must be air-dried and particle size reduced to pass a 0.5-mm screen for analysis. This proceduremust be performed carefully to preserve the samples representative characteristics (other than particle siz
21、e) while preparing theanalysis sample to be used in this procedure (see Practice E829).7.2 Refuse-Derived Fuel Ash, Fly Ash, Bottom Ash, or SlagThe method of sampling for this procedure should be based onagreement between involved parties.8. Sample Preparation8.1 Refuse-Derived Fuel:8.1.1 Weigh accu
22、rately 30 to 50 g of RDF analysis sample as prepared in 6.1 into a conditioned and preweighed fused quartzdish.8.1.2 Spread out the analysis sample of RDF in a layer not over 38.1 mm (112 in.) in depth.8.1.3 Place the dish in the muffle at a low temperature (not greater than 100C) and gradually heat
23、 to redness at such a rate asto avoid mechanical loss from too rapid expulsion of volatile matter.8.1.4 Complete the conversion to ash at a temperature of 800 to 900C (1470 to 1650F).8.1.5 Cool in a desiccator and stir the ash to ensure homogeneity of particle sizes. Be careful not to lose any ash f
24、rom the dishduring this stirring.8.1.6 Spread the ash in a thin layer in the dish, and ignite in a 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.
25、9 Calculate the percent ash as follows:%Ash5C 2A!/B 2A! 3100 (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, o
26、r slag by grinding the sample in an agate mortar to a particle size to pass aNo. 200 (75-m) sieve.8.2.2 Weigh accurately 6 to 10 g of RDF ash, fly ash, bottom ash, 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 be analyz
27、ed in a layer not over 6.4 mm (14 in.) in depth.E887 1528.2.4 Place the dish in the muffle at a low temperature (not greater than 100C), and gradually heat to redness at such a rateas to avoid mechanical loss from too rapid expulsion of volatile matter.8.2.5 Complete the conversion to ash at a tempe
28、rature of 800 to 900C (1470 to 1659F).8.2.6 Cool in a desiccator and stir the ash to ensure homogeneity of particle sizes. Be careful not to lose any ash from the dishduring this stirring.8.2.7 Spread the ash in a thin layer in the dish and ignite in a stream of oxygen for 112 h at 800 to 850C (1470
29、 to 1560F)to ensure complete and uniform oxidation 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 follows:%Residue after ignition5F 2D!/E 2D! 3100 (2)where:D = weight of fused quartz dish, g,E
30、= weight of fused quartz dish and sample, of RDF ash, fly ash, bottom ash or slag, g, andF = weight of fused quartz dish and residue after ignition of RDF 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 prepared RDF ash as prepared in
31、 8.1 or the residue of RDF ash, fly ash, bottomash, or slag as prepared in 8.2 into a platinum or graphite crucible.9.1.2 Add 1.0 g of Na2CO3. Mix the ash and Na2CO3 well, then add an additional 0.5 g of Na2CO3 to cover the mixture.9.1.3 Place the crucible into a clean silica or refractory tray, and
32、 place in a muffle furnace preheated to 1000C and maintainuntil 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 its side in a 300-mL casserole or beaker about one-third full of water.Warm and stir until the cake d
33、isintegrates and can be easily removed.9.1.6 By means of platinum tipped tongs, lift the crucible out of the liquid, rinsing it thoroughly with water followed by rinsingwith dilute hydrochloric acid (HCl, 1 + 3); adding the rinse to the casserole or beaker.9.2 Acid Dehydration:9.2.1 Very slowly and
34、cautiously add 20 mL of concentrated hydrochloric acid (HCl, sp gr 1.19) to the covered casserole orbeaker (see Note 2). Remove the cover and rinse. If any gritty particles are present, the fusion is incomplete and must be repeated,using a new sample and a larger amount of Na2CO3.NOTE 2This solution
35、 will tend to “creep” over the rim of the casserole unless the rim is kept hot and dry. This can be accomplished by applying heatfrom 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 5 to 10 mL of HC
36、l (concentrated), wait at least 2 min, then add anequal amount of water.9.2.4 Cover the casserole or beaker, and digest for 10 min on 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
37、 thoroughly with hot HCl (1 + 99), then with hot water.9.2.6 Reserve the residue.9.2.7 Again, evaporate the filtrate to dryness and bake the residue in an oven for 1 h at 105 to 110C.9.2.8 Cool, add 10 to 15 mL HCl (1 + 1) and digest on the steam bath or hot plate for 10 min.9.2.9 Dilute with an equ
38、al volume of water, filter immediately on a fresh filter paper, and wash the small amount of residuethoroughly with hot HCl (1 + 99), then with hot water.9.2.10 Transfer the papers containing the residues (from 9.2.6 and 9.2.9) to a weighed conditioned platinum crucible.9.2.11 Dry and ignite the pap
39、ers, first at a low heat until the carbon of the filter paper is completely consumed without flaming,and finally ignite at 1100 to 1200C until the weight becomes constant. Record weight of residue after ignition.9.3 Volatilization of Silicon Tetrafluoride:9.3.1 Treat the silica (SiO2) thus obtained,
40、 which will con-containtain impurities, in the crucible with 0.5 to 1 mL of water, 2 drops of H2SO4 (1 + 1) and 10 mL of HF.9.3.2 Cautiously evaporate to dryness on a hot plate or hot sand 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 desicca
41、tor and weigh.9.3.5 The difference between this weight and the weight previously obtained in 9.2.11 represents the amount of SiO2.E887 1539.4 BlankMake a blank determination, following the same procedures as used in 9.1.2 through 9.3.5 using the same amountsof reagents and correct the obtained in th
42、e analysis accordingly.10. Calculation10.1 Calculate the concentration of SiO2 as follows:10.1.1 Percent SiO2 on prepared sample as used in 9.1.1.%SiO25W12W2!2W32W4!/W53100 (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 o
43、f residue after treatment with HF and second ignition as in 9.3.4, g,W4 = weight of blank after treatment with HF and second ignition, 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 SiO2 in RDF (6.1).%SiO2 in RDF5G 3H!/100! (4)wh
44、ere:G = ash as found in 8.1.9, %, andH = SiO2 as found in 10.1.1, %.10.1.3 Percent SiO2 in RDF ash, fly ash, bottom ash, or slag (8.2).%SiO2 in RDF Ash,fly ash,bottom ash,or slag5I 3H!/100! (5)where:I = residue after ignition as found in 8.2.10, %, andH = SiO2 as found in 10.1.1, %.See Test Method E
45、791 for procedures to convert values to other bases.11. Precision and Bias11.1 Precision and bias statements cannot be made at this time for the measurement of SiO2 by this test method.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any i
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