ASTM D1857 D1857M-2018 Standard Test Method for Fusibility of Coal and Coke Ash.pdf

1、Designation: D1857/D1857M 17aD1857/D1857M 18Standard Test Method forFusibility of Coal and Coke Ash1This standard is issued under the fixed designation D1857/D1857M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year of last

2、revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This test method covers the observati

3、on of the temperatures at which triangular pyramids (cones) prepared from coal andcoke ash attain and pass through certain defined stages of fusing and flow when heated at a specified rate in controlled, mildlyreducing, and where desired, oxidizing atmospheres.1.2 The test method is empirical, and s

4、trict observance of the requirements and conditions is necessary to obtain reproducibletemperatures and enable different laboratories to obtain concordant results.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem m

5、ay not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1.3.1 All percentages are percent mass fractions unless otherwise noted.1.4 This standard does not purport to address all

6、 of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.5 This international standard was d

7、eveloped in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Doc

8、uments2.1 ASTM Standards:2D346D346/D346M Practice for Collection and Preparation of Coke Samples for Laboratory AnalysisD2013D2013/D2013M Practice for Preparing Coal Samples for AnalysisD3174 Test Method for Ash in the Analysis Sample of Coal and Coke from CoalD3180 Practice for Calculating Coal and

9、 Coke Analyses from As-Determined to Different BasesD3682 Test Method for Major and Minor Elements in Combustion Residues from Coal Utilization ProcessesD4326 Test Method for Major and Minor Elements in Coal and Coke Ash By X-Ray FluorescenceD6349 Test Method for Determination of Major and Minor Ele

10、ments in Coal, Coke, and Solid Residues from Combustion ofCoal and Coke by Inductively Coupled PlasmaAtomic Emission SpectrometryD7448 Practice for Establishing the Competence of Laboratories UsingASTM Procedures in the Sampling andAnalysis of Coaland CokeD7582 Test Methods for Proximate Analysis of

11、 Coal and Coke by Macro Thermogravimetric Analysis3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 The critical temperature points to be observed are as follows:3.1.2 fluid temperature, FTthe temperature at which the fused mass has spread out in a nearly flat layer with a maxim

12、umheight of 1.6 mm 116 in. as shown by the fifth cone, FT, in Fig. 1.1 This test method is under the jurisdiction of ASTM Committee D05 on Coal and Coke and is the direct responsibility of D05.21 on Methods of Analysis.Current edition approved Aug. 1, 2017Sept. 1, 2018. Published August 2017Septembe

13、r 2018. Originally approved 1961. Last previous edition approved in 2017 asD1857 17.D1857/D1857M 17a. DOI: 10.1520/D1857-17a.10.1520/D1857_D1857M-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standa

14、rdsvolume information, refer to the standards Document Summary page on the ASTM website.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 t

15、o adequately depict all changes accurately, 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 Con

16、shohocken, PA 19428-2959. United States13.1.3 hemispherical temperature, HTthe temperature at which the cone has fused down to a hemispherical lump at whichpoint the height is one half one-half the width of the base as shown by the fourth cone, HT, in Fig. 1.3.1.4 initial deformation temperature, IT

17、the temperature at which the first rounding of the apex of the cone occurs. Shrinkageor warping of the cone ignored if the tip remains sharp. In Fig. 1, the first cone shown is an unheated one; the second cone ITcone,IT, is a typical cone at the initial deformation stage.3.1.5 softening temperature,

18、 STthe temperature at which the cone has fused down to a spherical lump in which the height isequal to the width at the base as shown by the third cone, ST, in Fig. 1.4. Summary of Test Method4.1 Coal or coke ash, prepared by prescribed methods, is mixed with a small amount of a dextrin solution to

19、form a plastic mass.A cone mold is used to form triangular pyramids with the plastic mass, which are dried and mounted on a ceramic platform. Thecones and platform are rapidly heated in an electric furnace to 400 C (750 F).750 F. The cones and platform are then heatedat a rate of 8 C 6 3 C 15 F 6 5

20、Fmin in a reducing (CO/CO2) atmosphere, or an oxidizing (air) atmosphere. The ash conesare carefully observed as they pass through certain defined stages of melting and flow.5. Significance and Use5.1 The design of most coal combustion and coal conversion equipment anticipates that the ash either re

21、main solid or assumesome degree of fluidity, depending on the particular design. Ash fusibility temperatures help predict whether the ash will performproperly in the process for which the coal was chosen.5.2 Ash fusibility temperature values are used in various equations to predict the slagging tend

22、ency of ashes.6. Apparatus6.1 FurnaceAn electric furnace conforming to the following requirements may be used:6.1.1 Capable of maintaining a uniform temperature zone in which to heat the ash cones.6.1.2 Capable of maintaining the desired atmosphere surrounding the cones during heating. The compositi

23、on of the atmosphere,reducing or oxidizing, shall be maintained within the limits specified in Section 7. The desired atmosphere is to be obtained bymeans of gases introduced into the heating chamber. The furnace should be gas impervious.6.1.3 Capable of regulation so that the rate of temperature ri

24、se shall be 8 C 6 3 C 15 F 6 5 Fmin.6.1.4 Providing means of observing the ash cones during the heating. Observation on the same horizontal plane as thecone-support surface shall be possible.6.2 Cone MoldA commercially available cone mold, typically brass or made from a corrosion-resistant material

25、with a lowcoefficient of friction, as shown in Fig. 2. The cone shall be 19 mm 34 in. in height and 6.4 mm 14 in. in width at each sideof the base, which is an equilateral triangle. A steel spatula with a pointed tip, ground off to fit the cone depression in the mold,is suitable for removal of the a

26、sh cone.6.3 Refractory Tray MoldA mold with flat top and bottom surfaces to provide a refractory tray of suitable thickness tominimize warping.Asidemold not over 6.4 mm 14 in. high of any convenient shape, placed on an iron plate so that the top surfaceof the refractory mix can be struck off flat an

27、d parallel to the tray by means of a straight edge, straightedge, is satisfactory. Legsnot over 3 mm 18 in. long may be provided on the corners of the cone tray by suitable holes bored in the iron base plate of themold.6.4 Temperature Measuring InstrumentA type R or S thermocouple of platinum and pl

28、atinum-rhodium, protected from thefurnace gases by a glazed porcelain sheath, shall be used with a display readable to better than 5.5 C 10 F. The hot junctionof the thermocouple shall touch the end of the sheath and shall be located in the center of the furnace and immediately to the rearof the con

29、es. The thermocouple protective sheath shall be checked for cracks when there is difficulty in achieving the requirementsoutlined in Section 10.7. Reagents and Materials7.1 Ash-Cone Refractory TraysThe ash cones shall be mounted on refractory trays. These trays are commercially available,or can be p

30、repared using a mixture of equal parts by weight of kaolin and alumina. Materials conforming to the followingrequirements are to be used in preparing the refractory trays:FIG. 1 Critical Temperature PointsD1857/D1857M 1827.2 KaolinNF-grade powder passing a 75 m (U.S.A. Standard No. 200) sieve.7.3 Al

31、uminum OxideReagent grade Reagent-grade ignited powder passing a 150 m (U.S.A. Standard No. 100) sieve.7.4 Dextrin Solutionclear,Clear, filtered (if necessary) 10 % solution of dextrin containing 0.1 % salicylic acid as apreservative.7.5 Mold Release AgentpetroleumPetroleum jelly, thinned with keros

32、ene (if necessary), or a non-silicon-based mold releaseagent.7.6 Gold Wire0.51 mm diameter (twenty-four gage) or larger round wire of 99.98 % purity, but drawn from metal of 99.99 %purity, and having a melting point of 1064 C 1948 F.37.7 Nickel Wire0.51 mm diameter (twenty-four gage) or larger round

33、 wire of CP nickel, 99.98 % pure, fully annealed, andhaving a melting point of 1455 C 2651 F.38. Test Atmospheres8.1 Reducing Atmosphere TestA regulated flow of gas of the nominal composition, volume fraction 60 % carbon monoxideand volume fraction 40 % 6 5 % carbon dioxide, shall be maintained in t

34、he heating chamber throughout the test (Note 1) in thefurnace. The gas stream shall be regulated by any convenient means to provide a measured flow of 1.3 to 1.5 furnace volumes perminute.8.2 Cylinders of CO/CO2 GasTo assureensure that the CO/CO2 gas remains mixed, maintain the temperature of the cy

35、linderabove the critical temperature at which CO2 can liquefy and separate.8.3 Oxidizing Atmosphere TestAregulated stream of air shall be maintained throughout the test in the furnace. The gas streamshall be regulated by any convenient means to provide a measured flow of 1.3 to 1.5 furnace volumes p

36、er minute.9. Sample and Test Specimen Preparation9.1 Coal and CokePrepare the analysis sample in accordance with Practice D2013D2013/D2013M for coal or PracticeD346D346/D346M for coke by pulverizing the material to pass a 250 m (No. 60) U.S.A. standard sieve.9.2 Laboratory Ashing of Coal or Coke Ana

37、lysis SamplePrepare the ash from a thoroughly mixed analysis sample of coal orcoke (see 9.1). To facilitate the ashing process, spread the coal or coke in a layer about 6 mm (14 in.)in. in depth in a porcelain,quartz, fused silica, or fireclay roasting dish. Place the dish in a muffle furnace at amb

38、ient temperature and heat gradually so thatthe temperature reaches 500 C 6 10 C at the end of 1 h. For coals, continue heating the sample until the temperature rises from500 C 6 10 C to 750 C 6 15 C in 1 h. For cokes, continue heating the sample until the temperature rises from 500 C 6 10 C3 These t

39、emperatures are consistent with the ITS-90 temperature scale.Inch-poundInch-PoundUnits,in.SI Units,mm14 6.434 19.1112 38.12 50.23 76.2FIG. 2 Brass Cone MoldD1857/D1857M 183to 950 C 6 10 C in 1 h. Continue to heat at the final temperature (750 C or 950 C) until the test specimen reaches a constantmas

40、s or for an additional 2 h (Note 1). Allow the dish to cool, transfer to an agate mortar (Note 2), and grind to pass a 75 m (No.200) U.S.A. standard sieve. Reignite the ash at 750 C or 950 C for 112 h to ensure complete and uniform oxidation of the ash.9.2.1 The two-stage ashing procedure allows pyr

41、itic sulfur to be oxidized and sulfur oxides expelled before most metalcarbonates are decomposed. An ample supply of air in the muffle furnace must be assuredensured at all times to ensure completeoxidation of the pyritic sulfur and, more importantly, to efficiently remove the SO2 formed. Because of

42、 the possibility of SO2product being absorbed by alkali and alkaline earth metal oxides (especially CaO), it is advisable to not ash high pyritic sulfur coalswith coals that have high alkali or alkaline earth metal contents, or both.NOTE 1The D3174 and D7582 ashing procedures used in the determinati

43、on of ash from coal and/or coke samples and the D3682, D4326, and D6349ashing procedures used in preparing ash from coal or coke samples, or both, for major and minor element analysis are acceptable procedures for preparingash for the fusibility test.NOTE 2A mechanical agate mortar grinder will save

44、 time where many determinations are made.9.3 Preparation of ConesThoroughly mix the ignited ash in a mechanical mixer or on a sheet of glazed paper or oil cloth byraising first one corner to roll the ash over and then raising each of the other corners in rotation in the same manner until each corner

45、has been raised five times or more.9.3.1 Take sufficient ash for the number of cones desired from various parts of the bulk ash. Moisten the ash with a few dropsof a dextrin solution and work it into a stiff plastic mass with a spatula. Press the plastic material firmly with a spatula into thecone m

46、old to form the triangular pyramids. Strike off the exposed surfaces of the material smooth and remove the cones from themold by applying slight pressure at the base with a suitably pointed spatula. Previous coating of the mold with a very thin layerof petroleum jelly, thinned with kerosene (if nece

47、ssary), or a very thin coating of a non-silicon-based mold release agent, aids inpreventing adherence of the cones to the mold and in providing the sharp point and edges desired in the cone. With certain coalashes, cones with sharp points and edges can be obtained using distilled water in place of t

48、he dextrin solution and without the useof petroleum jelly.9.3.2 Place the cones in a suitable location to dry sufficiently to permit handling without deformation. Mount the dried conesvertically on a refractory tray.9.3.2.1 Follow the manufacturers recommendations for mounting the dry cones on comme

49、rcially available support trays.9.3.2.2 To prepare fresh support trays, moisten a portion of the well-mixed kaolin-alumina mixture with the minimum amountof water to make a workable, but stiff, plastic mass, and firmly press it into the support mold (Section (7.4). Strike off the surfaceof the mass flat and smooth with a steel spatula, moistening with one or two drops of water if necessary to obtain a smooth surface.A number of cones may be mounted on one base. Make shallow triangul