1、Designation: E 776 87 (Reapproved 2009)Standard Test Method forForms of Chlorine in Refuse-Derived Fuel1This standard is issued under the fixed designation E 776; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last rev
2、ision. 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 the formsof chlorine in refuse-derived fuel-three (RDF): total chlorine,water-sol
3、uble chloride, and water-insoluble chlorine.1.2 This test method may be applicable to any wastematerial from which a laboratory analysis sample can beprepared.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard
4、 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 applica-bility of regulatory limitations prior to use. For specificprecaution statemen
5、ts see Section 6 and 11.2.1.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterE 144 Practice for Safe Use of Oxygen Combustion BombsE 180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty ChemicalsE 287 Specific
6、ation for Laboratory Glass Graduated BuretsE711 Test Method for Gross Calorific Value of Refuse-Derived Fuel by the Bomb CalorimeterE 829 Practice for Preparing Refuse-Derived Fuel (RDF)Laboratory Samples for Analysis33. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 refuse-deri
7、ved fuelssolid forms of refuse-derivedfuels from which appropriate analytical samples may beprepared are defined as follows in ASTM STP 832:4RDF-1Wastes used as a fuel in as-discarded form withonly bulky wastes removed.RDF-2Wastes processed to coarse particle size with orwithout ferrous metal separa
8、tion.RDF-3Combustible waste fraction processed to particlesizes, 95 % passing 2-in. square screening.RDF-4Combustible waste fraction processed into powderform, 95 % passing 10-mesh screening.RDF-5Combustible waste fraction densified (compressed)into the form of pellets, slugs, cubettes, or briquette
9、s.3.1.2 total chlorineall chlorine as determined in therefuse-derived fuel.3.1.3 water-insoluble chlorinewater-insoluble chloridesand chlorine in the refuse-derived fuel.3.1.4 water-soluble chloridethose chlorides which arewater-solubilized by water extraction as determined in therefuse-derived fuel
10、.4. Summary of Test Method4.1 The forms of chloride and chlorine are determined. Thevarious procedures in the method convert the forms of chlorineinto a water-soluble chloride form that can be quantitated bytitration.4.1.1 Total ChlorineThe sample is combusted in an oxy-gen atmosphere. The chlorine
11、is converted to chloride andabsorbed in an alkaline solution.4.1.2 Water-Soluble ChloridesA portion of the analysissample is successively extracted with hot chloride-free water.4.1.3 Water-Insoluble ChlorineWater-insoluble chlorineis calculated from the results of the total chlorine and thewater-sol
12、uble chloride determination where:water2insoluble chlorine 5 total chlorine 2 water2soluble chlorides(1)1This test method is under the jurisdiction of ASTM Committee D34 on WasteManagement and is the direct responsibility of Subcommittee D34.03.02 onMunicipal Recovery and Reuse (Disbanded 06/09).Cur
13、rent edition approved July 1, 2009. Published August 2009. Originallyapproved in 1981. Last previous edition approved in 2004 as E 776 87 (2004).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards
14、volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.4Thesaurus on Resource Recovery Terminology, ASTM STP 832, ASTM, 1983,p. 72.1Copyright ASTM International, 100 Barr Harbo
15、r Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.2 The chlorides contained in the alkaline solution (4.1.1)and the extraction solution (4.1.2) are determined by potentio-metric (see Section 13) or modified Volhard titration (seeSection 14).5. Significance and Use5.1 The standa
16、rd is available to producers and users of RDFfor determining the content and forms of chlorine present in thefuel.6. Precautions6.1 Due to the origins of RDF in municipal waste, commonsense dictates that some precautions should be observed whenconducting tests on the samples. Recommended hygienicpra
17、ctices include use of gloves when handling RDF; wearingdust masks (NIOSH-approved type), especially while millingRDF samples; conducting tests under negative pressure hoodwhen possible; and washing hands before eating or smoking.7. Interferences7.1 Potentiometric Titration Method A:7.1.1 Iodide and
18、bromide are also titrated as chloride.Ferricyanide causes high results and must be removed. Chro-mate and dichromate interfere and should be reduced to thechromic state or be removed. Ferric iron interferes if present inan amount substantially higher than the amount of chloride.Chromic ions, ferrous
19、 ions, and phosphates do not interfere.7.1.2 Grossly contaminated sample solutions usually re-quire pretreatment. Where contamination is minor, some con-taminants can be destroyed simply by the addition of nitricacid.7.2 Volhard Titration Method B:7.2.1 Compounds that have a strong oxidizing action
20、inter-fere by reacting with thiocyanate. These compounds should bereduced beforehand by treatment with ferrous sulfate or asimilar reducing agent.7.2.2 Salts of mercury and palladium interfere by reactingwith thiocyanate. They may be removed by precipitation withhydrogen sulfide before the addition
21、of silver nitrate. Theexcess of sulfide is easily removed by gently boiling the acidsolution for a few minutes. Sulfite can be eliminated in thesame way.7.2.3 Cyanide is also precipitated by silver nitrate. It isusually determined separately by the Liebig-Deniges methodand a correction is applied to
22、 the results of the Volhardtitration.57.2.4 The Volhard method, as with the potentiometricmethod, directly applied to a mixture of halides can determineonly total halide content excluding fluoride. Preliminary treat-ment is necessary for the determination of chloride alone in amixture.68. Apparatus8
23、.1 Balance, having a sensitivity of 0.1 mg.8.2 Apparatus for Bomb Combustion of the Sample.8.2.1 Oxygen Bomb, similar to that used in the determina-tion of the calorific value of refuse-derived fuels as describedin Test Method E711.8.2.2 Capsule, for holding the sample, approximately 25mm in diamete
24、r at the top, approximately 12 mm deep, andconforming to Test Method E711.8.2.3 Firing Wire, as specified in Test Method E711.8.2.4 Firing Circuit, as specified in Test Method E711.5Scotts Standard Method of Chemical Analysis, edited by M. H. Furman, D.Van Nostrand Co., Inc., New York, NY.6Koltoff,
25、I. M., and Stenger, V. A., Volumetric Analysis II, IntersciencePublishers, Inc., New York, NY.FIG. 1 Graph From a Potentiometric Titration of ChlorideE 776 87 (2009)28.2.5 Metal Vessel, cylindrical, such that the bomb will befully immersed when approximately 2 L of water are added.8.3 Magnetic Stirr
26、er and Stirring Bars.8.4 Apparatus for Potentiometric Titration:8.4.1 Potentiometric Titration Assembly, using a silver in-dicator electrode and a calomel reference electrode containinga saturated sodium nitrate solution as a bridge.NOTE 1All glassware and graduated apparatus should be Class A orequ
27、ivalent as described in Specification E 287.9. Reagents9.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Societywhe
28、re such specifications are available.7Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.9.2 Purity of WaterUnless otherwise indicated, referenceto water shall be understood to
29、mean at least Type III reagentwater conforming to Specification D 1193.9.3 Potassium Hydroxide Solution (0.2 N)Dissolve 13.2g of potassium hydroxide (KOH) in water and dilute to 1 Lwith water.9.4 OxygenThe oxygen used for combustion shall be freeof combustible matter. Oxygen manufactured from liquid
30、 air,guaranteed to be greater than 99.5 % pure, will meet thisrequirement.9.5 Sodium Chloride (NaCl)Primary standard quality (pu-rity of 100 6 0.02 %).9.6 Sodium Chloride, Primary Standard Solution (0.025N)Crush 10 to 20 g of primary standard sodium chloride(NaCl) to 100-mesh fineness and dry in a g
31、lass container at120C for 2 h. Stopper and keep desiccated. Dissolve 5.844 g6 0.1 mg of dried primary standard NaCl in water and diluteto 1 L. Dilute 25.00 mL of this solution to 100.0 mL.9.7 Methanol.9.8 Nitric Acid (1 + 1)Mix equal volumes of concentratednitric acid (HNO3, sp, gr, 1.42) and water.
32、9.9 Silver Nitrate, Standard Solution (0.025 N)Dissolve4.247 g of silver nitrate (AgNO3) in water and dilute to 1 L.Store in an amber glass bottle. Standardize against 0.025 Nsodium chloride solution as directed in 13.1.1 and 14.1.1.9.10 Potassium Chromate Potassium DichromateIndicator(K2CrO4K2Cr2O7
33、)Dissolve 4.2 gofK2CrO4and 0.7 g of K2Cr2O7in 100 mL of water.9.11 Nitrobenzene.9.12 Ferric Ammonium Sulfate Indicator SolutionAddsufficient concentrated HNO3(sp gr 1.42) to a cold saturatedsolution of ferric ammonium sulfate FeNH4(SO4)212H2O toremove the brown color.9.13 Potassium Thiocyanate, Stan
34、dard Solution (0.025N)Dissolve3gofpotassium thiocyanate (KCNS) in freshlydistilled or boiled water, dilute to 1 L, and standardize against0.025 N AgNO3solution as directed in 14.1.2.10. Sampling10.1 RDF products are frequently nonhomogeneous. Forthis reason significant care should be exercised to ob
35、tain arepresentative laboratory sample from the RDF lot to becharacterized.10.2 The sampling method for this procedure should bebased on agreement between the involved parties.10.3 The laboratory sample must be air-dried and theparticle size reduced to pass a 0.5-mm screen as described inPractice E
36、829. This procedure must be performed carefully topreserve the samples representative characteristics (other thanparticle size) while preparing the analysis sample to be used inthe procedures.PREPARATION OF CHLORINE SOLUTIONS FORANALYSIS11. Total Chlorine (Oxygen Bomb Method)11.1 Preparation of Samp
37、le and Bomb (see Note 3):11.1.1 Sample WeightWeigh to the nearest 0.1 mg about 1g of thoroughly mixed air-dried analysis RDF sample into thebomb capsule.Apellet may be made from the air-dried analysisRDF sample, accurately weighed, and placed into the bombcapsule. Place the capsule containing the sa
38、mple into thecapsule holder.NOTE 2There is a tendency for chlorine to adhere to the bomb walls,especially if the bomb is pitted or has been used previously to determinehigh levels of chlorine. Unless the bomb is thoroughly cleaned before use,the blanks may have values in excess of reality.11.1.2 Fir
39、ing WireConnect a length of firing wire to theignition terminals in such a manner that the loop of firing wireis in contact with the sample.11.1.3 Bomb PreparationAdd 20 to 25 mL of 0.02 Npotassium hydroxide solution to the bomb and wet the entireinternal surface of the bomb with this solution (see
40、Note 3).Assemble the bomb.NOTE 3Sodium hydroxide solution at appropriate concentration maybe used.11.2 Addition of OxygenAdmit oxygen to the bombslowly to avoid blowing the sample from the capsule until apressure of 25 atm is reached.11.2.1 WarningThe following precautions are recom-mended for safe
41、calorimeter operation. Additional precautionsare given in Practice E 144.11.2.1.1 The weight of RDF sample and the pressure of theoxygen admitted to the bomb must not exceed the bombmanufacturers recommendations.11.2.1.2 Bomb parts should be inspected carefully after eachuse. Threads on the main clo
42、sure should be checked frequentlyfor wear. Cracked or significantly worn parts should bereplaced. The bomb should be returned to the manufactureroccasionally for inspection and possibly proof firing.7Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, D
43、C. 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 States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.E 776 87 (2009)311
44、.2.1.3 The oxygen supply cylinder should be equippedwith an approved type of safety device, such as a reducingvalve, in addition to the needle valve and pressure gage used inregulating the oxygen feed to the bomb. Valves, gages, andgaskets must meet industry safety codes. Suitable reducingvalves and
45、 adaptors for 300 to 500 psi (2070 to 3450 kPa)discharge pressures are obtainable from commercial sources ofcompressed gas equipment. The pressure gage shall be checkedperiodically for accuracy.11.2.1.4 During ignition of a sample, the operator must notpermit any portion of his body to extend over t
46、he calorimeter.11.3 Preparation of the Chlorine SolutionImmerse thebomb in a cold-water bath, connect it to the firing circuit, andclose the circuit to ignite the sample. Allow the bomb to standin the water bath for not less than 10 min after firing. Removethe bomb from the water bath, invert the bo
47、mb and shake forabout 10 min (Note 4). Release the pressure at a slow, uniformrate so that the pressure is reduced to atmospheric in not lessthan 1 min. Open the bomb and examine the inside for tracesof unburned material or sooty deposits. If any are found,discard the determination and thoroughly wa
48、sh all parts of thebomb interior before using it again. If no unburned material orsooty deposits are present, rinse the interior of the bomb, thesample capsule, and the interior surface of the bomb cover witha fine jet of hot water and collect the contents and washings ina beaker or flask.NOTE 4Inve
49、rting and shaking a heavy, wet, and possibly slipperybomb may present a hazard. Precautions should be taken when performingthis function.12. Extraction of Water-Soluble Chlorides12.1 Preparation of the Chloride SolutionWeigh to thenearest 0.1 mg about5gofthoroughly mixed, air-dried RDFanalysis sample. Transfer to a 500-mL beaker and add 100 mLof hot water. Heat to close to boiling for12 h with occasionalstirring to ensure thorough wetting of the sample. Decant thesupernatant liquid through a fast, qualitative filter paper col-lecting t
