ASTM D6316-2009a 516 Standard Test Method for Determination of Total Combustible and Carbonate Carbon in Solid Residues from Coal and Coke.pdf

1、Designation: D 6316 09aStandard Test Method forDetermination of Total, Combustible and Carbonate Carbonin Solid Residues from Coal and Coke1This standard is issued under the fixed designation D 6316; the number immediately following the designation indicates the year oforiginal adoption or, in the c

2、ase of revision, the year 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 total,combustible, and carbonate carbon rema

3、ining in the solidbyproducts of combustion from boiler furnaces and similarreactors, including ash, flyash, char, slag, and similar materials.1.2 This test method is intended for the use of industry todetermine the performance of boiler furnaces and similarcombustion reactors and aid in determining

4、the quality of thesolid residue from combustion.1.3 This test method comprises the use of any of severalmethods to determine total carbon content combined with anyof several methods to determine carbonate carbon, and thecalculation, by difference, of the combustible carbon remainingin a sample.1.4 A

5、lternatively, this test method applies to the determina-tion of total carbon remaining in a material after acidificationwith strong acid to evolve carbonate carbon. In this case, thecombustible carbon is the total carbon measured in the sampleafter acidification.1.5 The values stated in SI units are

6、 to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 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

7、and to determine theapplicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 121 Terminology of Coal and CokeD 513 Test Methods for Total and Dissolved Carbon Diox-ide in WaterD 1756 Test Method for Determination as Carbon Dioxideof Carbonate Carbon in CoalD

8、3178 Test Methods for Carbon and Hydrogen in theAnalysis Sample of Coal and Coke3D 5373 Test Methods for Instrumental Determination ofCarbon, Hydrogen, and Nitrogen in Laboratory Samples ofCoal and CokeE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2

9、.2 Other Standards:ANSI/ASME Standard, PTC 38-1980 Determining the Con-centration of Particulate Matter in A Gas Stream and USEPA Standard CFR 60 Appendix A, Method 1743. Terminology3.1 Definitions: For additional definitions of terms used inthis test method, refer to Terminology D 121.3.1.1 carbona

10、te carbon, nthe carbon content present inthe solid products derived from the combustion or reaction ofcoal, coal byproducts, or coke as carbonates and which isnon-combustible in standard industry practice.3.1.2 combustible carbon, ncarbon content remaining inthe solid products derived from the combu

11、stion or reaction ofcoal, coal byproducts, or coke, exclusive of carbonate in anyform.3.1.3 total carbon, ncarbon content remaining in the solidproducts derived from the combustion or reaction of coal, coalbyproducts, or coke, inclusive of carbonate in any form.4. Summary of Test Method4.1 Total Car

12、bonThe determination of total carbon ismade by the oxidative thermal decomposition of a weighedquantity of sample in a closed system and, after completeoxidation and purification of the resulting gaseous products,measurement of the carbon dioxide produced by one of severalmethods.4.1.1 Absorptive De

13、termination of Total CarbonTheevolved carbon dioxide is fixed on an absorption train and ismeasured quantitatively by weighing the absorbent (see TestMethods D 3178).1This test method is under the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct responsibility of Subcommittee D05

14、.29 on MajorElements in Ash and Trace Elements of Coal.Current edition approved April 15, 2009. Published June 2009. Originallyapproved in 1998. Last previous edition approved in 2009 as D 6316 - 09.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service

15、 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 www.astm.org.4Available from American National Standards Institute (ANSI), 25 W.

16、 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.2 Instrumental Determination of Total CarbonThecarbon dioxide is measured quantitatively by an electronicdetection system

17、 calibrated against an appropriate referencestandard (see Test Methods D 5373).4.2 Carbonate CarbonThe determination of carbonatecarbon is made by decomposing a weighed quantity of thesample with a dilute mineral acid, and after the purification ofthe evolved gases, measuring quantitatively the evol

18、ved carbondioxide.4.2.1 Absorptive Determination of Carbonate CarbonThecarbon dioxide is liberated by acidification and heating. Theevolved gases are passed through a purification train and theCO2is fixed as Na2CO3on a preweighed absorption unit andis measured gravimetrically (see Test Method D 1756

19、).4.2.2 Coulometric Determination of Carbonate CarbonThe carbon dioxide is liberated by acidification and heating.The evolved gas is swept through a scrubber and into anabsorption cell where it is coulometrically titrated (see Part Bof Test Methods D 513).4.2.3 Instrumental Determination of Carbonat

20、e CarbonThe carbon dioxide is liberated by acidification and heating.The evolved gases are purified and measured quantitatively byan electronic detection system against an appropriate referencestream. This test method resembles that for the instrumentaldetermination of total carbon, with the provisi

21、on for samplecombustion replaced by a provision for acidification. In prac-tice, this test method uses an adaptation to instruments de-signed to measure total carbon content.4.3 Combustible Carbon by Prior AcidificationThe deter-mination of combustible carbon is made directly by firstacidifying and

22、heating to dryness a weighed sample. Allcarbonate carbon present is evolved as carbon dioxide. Thedried sample is then analyzed for total carbon content as above.No determination of carbonate carbon is made and the carboncontent measured as total carbon is the combustible carbon.5. Significance and

23、Use5.1 The combustible carbon content of solid residues is usedto calculate efficiency of fuel combustion in boiler furnaces andsimilar combustors.5.2 Combustible carbon values are also used to determinethe residual fuel value of incompletely combusted/reacted coaland coke in other reactors that con

24、sume carbonaceous fuels(examples include fluidized bed furnaces and liquefaction,gasification and pyrolysis reactors).5.3 The combustible carbon content of flyash is an impor-tant parameter in the use of flyash as a cement additive.6. Interferences6.1 The interferences for the determination of total

25、 carboncontent are those specified in the referenced standard methods,Test Methods D 3178 and Test Methods D 5373, with thefollowing added stipulation.6.1.1 The temperature and conditions of combustion thatensure complete conversion of a residue samples total carboncontent to carbon dioxide may be d

26、ifferent than those requiredfor conversion in coal samples. It is absolutely imperative thatthe instrumental conditions used will ensure complete conver-sion of mineral carbonate in any amount or form.6.2 The interferences for the determination of carbonatecarbon are those specified in the reference

27、d methods, TestMethod D 1756 and Part B of Test Methods D 513 with thefollowing stipulation6.2.1 Some coal combustion residues contain significantamounts of reactive elements such as CaO which will absorbcarbon dioxide on exposure to open air and form mineralcarbonates. This will influence the calcu

28、lated amount ofcombustible carbon in the sample only if there was carbondioxide chemisorption from the air between the time of thecarbonate determination and the total carbon determination.Therefore, it is necessary that the sample be protected from airexposure.6.3 The mineral acid and temperature r

29、equired for prioracidification of the analytical sample shall not interfere withthe amount of combustible carbon present in the sample or theanalytical determination of carbon. The use of oxidizing acidssuch as concentrated nitric acid may oxidize a portion of thecombustible carbon. Other acids such

30、 as hydrochloric acid maybe incompatible with the reagents used to purify the gas streamin the instrumental determination of carbon. Sulfuric acid hasa relatively high boiling point and is difficult to remove fromthe sample by drying. A solution of 10 % nitric acid issuggested for use in this proced

31、ure.7. Apparatus7.1 The apparatus used is specified in the respective refer-enced method.7.2 Total Carbon Content:7.2.1 Absorptive Determination of Total CarbonThe ap-paratus consists of an oxygen-purifying train, combustion unit,and absorption train of the type and configuration specified inTest Me

32、thods D 3178.7.2.2 Instrumental Determination of Total CarbonBecause a variety of instrumental components and configura-tions can be used satisfactorily for these test methods, nospecifications are presented here with respect to overall systemdesign. However, the apparatus shall be capable of comple

33、telyconverting the carbon content to carbon dioxide, and thedetection system shall determine the carbon dioxide individu-ally and without interference.7.3 Carbonate Carbon Content:7.3.1 Absorptive Determination of Carbonate CarbonTheapparatus shall consist of an air purifying train, reaction unit,an

34、d absorption unit of the type and configuration specified inTest Method D 1756.7.3.2 Coulometric Determination of Carbonate CarbonThe apparatus shall consist of an evolution unit, a carbondioxide coulometer, scrubber, and pH meter of the type andconfiguration specified in Part B of Test Methods D 51

35、3.7.3.3 Instrumental Determination of Carbonate CarbonThe apparatus shall consist of a heated acidification unit that isinstalled by bypassing the combustion system in a devicedesigned for the determination of total carbon content. Thegas-purifying system of such instrument shall be capable ofcomple

36、tely removing the water content and acid gases pro-duced as byproducts of the carbon dioxide evolution. Thedetection system shall measure the evolved carbon dioxide asan individual species and without interference.D 6316 09a27.4 Combustible Carbon by Prior AcidificationThe cru-cibles used for this m

37、ethod must be free of carbonate, inert tothe mineral acid used, and compatible with the instrument usedfor measuring total carbon. The acidified sample is heated todryness using a laboratory hotplate capable of maintaining thefine temperature control required to dry the sample withoutmaterial loss o

38、f sample as a result of spattering or boilover. Theinstrument used shall meet the requirements of Test MethodsD 5373 and be capable of removing the additional acid gasesthat result from the mineral acid used for evolving the carbondioxide before determining carbon content.8. Reagents8.1 Purity of Re

39、agentsReagent 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 Society,where such specifications are available.5Other grades may beused, provide

40、d it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.9. Standards9.1 There are currently no standard reference materials ofcoal or coke residues that are certified for combustible carbonor carbonate carbon conte

41、nt. However, other types of standardmaterials can be used for both method validation and instru-ment calibration. These include:9.1.1 Buffalo River Sediment (NIST 2704)Total carbon =3.348 6 0.016 %.9.1.2 Carbonate Primary Standard GradeFor example,CaCO3total carbonate carbon = 12.00 %.9.1.3 CoalBitu

42、minous (NIST 1632b) total carbon = 76.866 0.26 %.9.1.4 EDTA Primary Standard GradeTotal carbon =41.07 %.10. Sample Preparation10.1 If moist or wet, the combustion residue sample6will bepredried at 107 6 3C. Drying time should be the minimumrequired to ensure complete dryness of the sample to minimiz

43、eabsorption of carbon dioxide from the air (see 6.2.1).10.2 The method of sample preparation used is specified inthe respective referenced method.10.3 Samples in excess of 50 g should be divided by rifflingto ensure a representative analysis sample. Samples of 50 g orless should be prepared in their

44、 entirety.10.4 The analysis sample shall initially be prepared to passthrough a 250-m (# 60 U.S. standard) sieve. If required by thecharacteristics of the instrument system or analytical precisionof the resulting data or both, the analysis sample should beground to pass through a 75-m (# 200 U.S. st

45、andard) sieve.711. Instrument Preparation and Verification11.1 The preparation of equipment and instruments is speci-fied in the respective referenced methods and the manufactur-ers instructions.11.2 The proper functioning of the equipment and theoperational parameters should be verified by analyzin

46、g blanksand standard materials that contain carbonate carbon andcombustible carbon.11.2.1 The proper combustion temperature and conditionsnecessary to convert the carbonate carbon to carbon dioxidemay be determined by measuring the carbon content of acarbonate standard. Measured carbon values of les

47、s than thecertified value indicate incomplete conversion of carbonates.11.2.2 Combustion accelerants such as magnesium powder,thermite (aluminum powder and iron oxide), and tin powdercan be used to ensure the total conversion of carbonates tocarbon dioxide by significantly raising the reaction tempe

48、ratureduring combustion.12. Procedure12.1 Calibrate the instruments using the methods describedin the referenced methods.12.1.1 The calibration range for these measurements shouldbe in the range of expected carbon values for the analyticalsamples.12.2 Determine the total carbon content of the sample

49、material by any of the referenced methods.12.3 Determine the carbonate carbon content of the samplematerial by any of the referenced methods, or12.4 Combustible Carbon by Prior AcidificationTare acrucible appropriate to the carbon analyzer used8to the nearest0.1 mg. Weigh a 100- to 500-mg portion of the analysis sampleto the nearest 0.1 mg. Add a sufficient amount of 10 % HNO3dropwise to wet the sample. Allow the sample to stand forseveral minutes. Dry the sample completely on a hotplate withlow heat (150C), taking care that the sample does not spatter.Al