1、Designation: E 953 88 (Reapproved 2004)Standard Test Method forFusibility of Refuse-Derived Fuel (RDF) Ash1This standard is issued under the fixed designation E 953; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the observation of the tempera-tures at which triangular pyramids (cones) prepared from RDFash att
3、ain and pass through certain stages of fusing and flowwhen heated at a specific rate in controlled, mildly-reducing,and oxidizing atmospheres.1.2 The test method is empirical, and strict observance ofthe requirements and conditions is necessary to obtain repro-ducible temperatures and enable differe
4、nt laboratories to obtainconcordant results.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 problems, if any, associated with its use. It is theresponsibility o
5、f the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. See Section 6 foradditional hazard information.2. Referenced Documents2.1 ASTM Standards:2E 180 Practice for Determining the Precision Data ofAST
6、M Methods for Analysis and Testing of IndustrialChemicalsE 829 Practice for Preparing Refuse-Derived Fuel (RDF)Laboratory Samples for Analysis3. Terminology3.1 Definitions and Symbols:3.1.1 The critical temperature points to be observed are asfollows, denoting the atmosphere used:3.2 initial deforma
7、tion temperature, ITthe temperature atwhich the first rounding of the apex of the cone occurs.Shrinking or warping of the cone is ignored if the tip remainssharp. In Fig. 1, the first cone shown is an unheated one; thesecond cone, IT, is a typical cone at the initial deformationstage.3.3 softening t
8、emperature, STthe temperature at whichthe cone has fused down to a spherical lump in which theheight is equal to the width at the base as shown by the thirdcone, ST, in Fig. 1.3.4 hemispherical temperature, HTthe temperature atwhich the cone has fused down to a hemispherical lump atwhich point the h
9、eight is one half the width of the base asshown by the fourth cone, HT, in Fig. 1.3.5 fluid temperature, FTthe temperature at which thefused mass has spread out in a nearly flat layer with amaximum height of 1.6 mm (116 in.) as shown in the fifthcone, FT, in Fig. 1.3.6 forms of refuse-derived fuel (
10、RDF):RDF-1Waste used as a fuel in as-discarded form.RDF-2Waste processed to coarse particle size with orwithout ferrous metal separation.RDF-3Shredded fuel derived from municipal solid waste(MSN) that has been processed to remove metal, glass, andother inorganics. This material has a particle size s
11、uch that 95weight % passes through a 2-in. square mesh screen.RDF-4Combustible waste processed into powder form, 95weight % passing a 10-mesh screening.RDF-5Combustible waste densified (compressed) into theform of pellets, slugs, cubettes, or briquettes.RDF-6Combustible waste processed into liquid f
12、uel.RDF-7Combustible waste processed into gaseous fuel.4. Significance and Use4.1 The standard is available to producers and users of RDFto use in determining the fusibility of ash produced from RDF.4.2 Limitations of Ash Fusibility DataAsh fusibility dataare too often over-interpreted. In practice,
13、 types of burningequipment, rate of burning, temperature and thickness of firebed or ball, distribution of ash forming mineral matter in theRDF, and viscosity of the molten ash may influence ashbehavior more than the ash fusibility characteristics determinedby the laboratory test. Furthermore, condi
14、tions existing duringapplied combustion of RDF are so complex that they areimpossible to duplicate completely in a small-scale laboratory1This test method is under the jurisdiction of ASTM Committee D34 on WasteManagement and is the direct responsibility of Subcommittee D34.03.02 onMunicipal Recover
15、y and Reuse.Current edition approved April 1, 2004. Published May 2004. Originallyapproved in 1983. Last previous edition approved in 1998 as E 953 88 (1998).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of A
16、STMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.test. Therefore, the test should be considered an empirical oneand the data, at best, on
17、ly qualitative.5. Apparatus5.1 FurnaceAny gas-fired or electric furnace conformingto the following requirements may be used.5.1.1 The furnace shall be capable of maintaining a uniformtemperature zone in which to heat the ash cones. This zoneshall be such that the difference in the melting point of 1
18、2.7mm (12 in.) pieces of pure gold wire when mounted in place ofthe ash cones on the cone support shall be not greater than11C (20F) in a reducing atmosphere test run.5.1.2 The furnace shall be capable of maintaining thedesired atmosphere surrounding the cones during heating. Thecomposition of the a
19、tmosphere, reducing or oxidizing, shall bemaintained within the limits specified in Section 7. The desiredatmosphere in the gas-fired furnace surrounding the cones shallbe obtained by regulation of the ratio of gas to air in thecombustion mixture. The desired atmosphere in the electricfurnace shall
20、be obtained by means of gases introduced into theheating chamber. The muffle shall be gas-impervious, free fromcracks, and the closure-plug tight fitting. Since state-of-the-artfurnaces vary somewhat in design, the gas supply inlet tubeshall be installed per instructions of furnace manufacturer.5.1.
21、3 The furnace shall be capable of regulation so that therate of temperature rise shall be 8 6 3C (15 6 5F) perminute.5.1.4 The furnace shall provide a means of observing theash cones during the heating. Observation shall be on the samehorizontal plane as the cone-support surface.5.2 Cone MoldA comme
22、rcially available cone mold asshown in Fig. 2 shall be used. The cone shall be 19 mm (34 in.)in height and 6.4 mm (14 in.) in width at each side of the basewhich is an equilateral triangle.5.2.1 A steel spatula with a pointed tip, ground off to fit thecone depression in the mold, is suitable for rem
23、oval of the ashcone.5.3 Optical Pyrometer or Thermocouple, for temperaturemeasurements, conforming to the following requirements:5.3.1 Optical PyrometerAn optical pyrometer of the dis-appearing filament type shall be used. The instrument shallhave been calibrated to be accurate within 11C (20F) up t
24、o1400C (2550F) and within 16C (30F) from 1400 to 1600C(2550F to 2900F) (Note 1). The pyrometer filament shall besighted on the cones until the softening point temperature (Fig.1) has been passed, and then sighted on the cone support. Thepyrometer shall have readable graduations not larger than5.5C (
25、10F).NOTE 1The pyrometer equipment shall be standardized periodicallyby a suitably equipped standardizing laboratory such as that of theNational Bureau of Standards, or checked periodically against equipmentcertified by the National Bureau of Standards.5.3.2 ThermocoupleA thermocouple of platinum an
26、dplatinum-rhodium, protected from the furnace gases by aglazed porcelain sheath, shall be used with a high-resistancemillivoltmeter or potentiometer accurate and readable to within5.5C (10F). The sheath shall be sealed to the furnace wall byalundum cement. The hot junction of the thermocouple shallt
27、ouch the end of the sheath and shall be located in the center ofthe muffle and immediately to the rear of the cones. Thethermocouple protective sheath shall be checked periodicallyfor cracks. The thermocouple and its meter shall meet therequirements of Section 10. The potentiometer or millivoltme-te
28、r shall be located or shielded adequately as to prevent radiantor convection heating of the cold junction. The room tempera-ture compensator shall be adjusted to the existing temperature.5.4 Ash-Cone Refractory SupportThe ash cone shall bemounted on a refractory base composed of a mixture of equalpa
29、rts by weight of kaolin and alumina conforming to thefollowing requirements:5.4.1 KaolinNF-Grade powder passing a No. 200 (0.074mm) sieve.5.4.2 Aluminum OxideReagent grade powder passing aNo. 100 (0.149 mm) sieve.5.5 Refractory Support MoldA mold with flat top andbottom surfaces to provide a refract
30、ory support of suitablethickness to minimize warping shall be used. A side mold notover14 in. (6.4 mm) high of any convenient shape, placed onan iron plate so that the top surface of the refractory mix canbe struck off flat and parallel to the base by means of astraightedge, is satisfactory. For ele
31、ctric furnace use, legs notover3mm(18 in.) long may be provided on the corners of thecone support by suitable holes bored in the iron base plate ofthe mold.FIG. 1 Critical Temperature PointsU.S. Customary Units.in.SI Units,mm14 6.434 19.1112 38.12 50.23 76.2FIG. 2 Brass Cone MoldE 953 88 (2004)25.6
32、Gold Wire,3Twenty-four gage or larger round wire of99.98 % purity, but drawn from metal of 99.99 % purity, andhaving a melting point of 1063C (1945F).5.7 Nickel Wire,4Twenty-four gage or larger round wire ofCP nickel 99.98 % pure, fully annealed, and having a meltingpoint of 1452C (2645F).6. Hazards
33、6.1 Due to the origins of RDF in municipal waste, commonsense dictates that some precautions should be observed whenconducting tests on the samples. Recommended hygenic prac-tices include use of gloves when handling RDF; wearing dustmasks (NIOSH-approved type); especially while milling RDFsamples; c
34、onducting tests under a negative pressure hood whenpossible; and washing hands before eating or smoking.6.2 Good laboratory practices dictate the precautions thatshould be observed when using compressed gases such ashydrogen or carbon monoxide as reducing gases.7. Test Atmosphere57.1 Gas Fired Furna
35、ce:7.1.1 Reducing Atmosphere TestA mildly reducing atmo-sphere surrounding the cones shall be maintained during thetest in the gas-fired furnace. Hydrogen, hydrocarbons, andcarbon monoxide shall be considered as reducing gases;oxygen, carbon dioxide, and water vapor shall be considered asoxidizing g
36、ases. Nitrogen is inert. The ratio by volume ofreducing gases to oxidizing gases in the atmosphere shall bebetween the limits of 20 to 80 %, that is, on a nitrogen-freebasis, the total amount of reducing gases present shall bebetween the limits of 20 and 80 volume %. A flame 150 to 200mm (6 to 8 in.
37、) in height and tinged with yellow above thefurnace outlet has been found to provide an atmosphere withinthe specified limits.7.1.2 Oxidizing Atmosphere TestAn atmosphere contain-ing a minimum amount of reducing gases shall be maintainedsurrounding the cones during the test in the gas-fired furnace.
38、On a nitrogen-free basis, the volume of the reducing gasespresent in the atmosphere will not exceed 10 volume %.Combustion with the maximum possible quantity of air withpreservation of the specified rate of temperature increase hasbeen found to provide an atmosphere within the specifiedlimits. A com
39、pletely blue flame, not over 50 mm (2 in.) inheight above the outlet at the beginning of the test, provides thedesired atmosphere; and, by regulation of the combustiongas-air ratio, the specified atmosphere and temperature rise canbe maintained.7.2 Electric Furnace:7.2.1 Reducing Atmosphere TestA re
40、gulated flow of gasof the nominal composition, 60 % carbon monoxide and 40 65 volume % carbon dioxide,6shall be maintained in the heatingchamber throughout the test (Note 2) in the electric furnace.The gas stream shall be regulated by any convenient means toprovide a measured flow of 1.3 to 1.5 furn
41、ace volumes perminute.NOTE 2New cylinders of the mixed gas for which a certified analysisis not available should be mixed before use by laying the cylinder on itsside with the protective screw cap in place. The cylinder should then berolled back and forth, 6 to 10 ft in each direction, approximately
42、 15 times.Certified analyses of each cylinder or batch can be obtained for a smallextra charge.7.2.2 Oxidizing Atmosphere TestA regulated stream of airshall be maintained throughout the test in the electric furnace.The gas stream shall be regulated by any convenient means toprovide a measured flow o
43、f 1.3 to 1.5 furnace volumes perminute.8. Preparation of Ash8.1 Use RDF milled to passing a 0.5-mm (0.02-in.) sieveprepared in accordance with Practice E 829 to obtain the ash byincineration in a well-ventilated muffle furnace. The quantity ofRDF required will vary with the ash content; usually 3 to
44、 5 gof ash will suffice for cones for several check determinations.Spread out the analysis sample of RDF in a layer approxi-mately 6.4 mm (14 in.) in depth in a fireclay or porcelainroasting dish. Place the dish in the muffle at a low temperature,and gradually heat to redness at such a rate as to av
45、oidmechanical loss from too rapid expulsion of volatile matter.The rate of temperature rise of 500C (932F) in 1 h was foundto be satisfactory. Complete the conversion to ash at atemperature of 800 to 900C (1470 to 1650F). Transfer the ashto an agate mortar (Note 3), and grind so it will pass a No. 2
46、00(0.074 mm) sieve.NOTE 3Amechanical agate mortar grinder will save time where manydeterminations are made. An iron mortar or pestle is not recommendedbecause of metallic contamination.8.2 Spread the ash in a thin layer in a fireclay, silica, orporcelain dish and ignite it in a stream of oxygen for
47、112 hat800 to 850C (1470 to 1560F) to ensure complete and uniformoxidation of the ash. Any tube or muffle-type furnace which,when supplied with an oxygen flow of not less than one furnacevolume in 5 min will maintain a highly oxidizing atmosphere,is suitable.NOTE 4It has been found that in most samp
48、les, the initial ignitionoutlined in 8.1 is sufficient to convert the RDF to ash and the reignitionstep in 8.2 is not necessary. Reignition of the ash should be made only ifan observable amount of noncombustible matter or carbon is present.9. Preparation of Cones9.1 Thoroughly mix the ignited ash in
49、 a mechanical mixeror on a sheet of glazed paper or oil cloth by raising first onecorner to roll the ash over, and then raising each of the othercorners in rotation in the same manner until each corner hasbeen raised five times or more.3Gold wire of this purity can be purchased from the Baker Dental Division ofEngelhard Industries, Inc., 850 Passaic Ave., East Newark, NJ 07029.4Nickel wire of this purity can be purchased with the additional specifications ofhaving a minimum coefficient of resist for 0 to 100C of 0.006
