1、Designation: D1857/D1857M 17Standard 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 revision. A numb
2、er 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 observation of the temper
3、a-tures at which triangular pyramids (cones) prepared from coaland coke ash attain and pass through certain defined stages offusing and flow when heated at a specified rate in controlled,mildly reducing, and where desired, oxidizing atmospheres.1.2 The test method is empirical, and strict observance
4、 ofthe requirements and conditions is necessary to obtain repro-ducible temperatures and enable different laboratories to obtainconcordant results.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact e
5、quivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.3.1 All percentages are percent mass fractions unlessotherwise noted.1.4 This standard does not purport to address all of thesafety concer
6、ns, 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.2. Referenced Documents2.1 ASTM Standards:2D346 Practice for Collection and Preparat
7、ion of CokeSamples for Laboratory AnalysisD2013 Practice for Preparing Coal Samples for AnalysisD3174 Test Method for Ash in the Analysis Sample of Coaland Coke from CoalD3180 Practice for Calculating Coal and Coke Analysesfrom As-Determined to Different BasesD3682 Test Method for Major and Minor El
8、ements inCombustion Residues from Coal Utilization ProcessesD4326 Test Method for Major and Minor Elements in Coaland Coke Ash By X-Ray FluorescenceD6349 Test Method for Determination of Major and MinorElements in Coal, Coke, and Solid Residues from Com-bustion of Coal and Coke by Inductively Couple
9、dPlasmaAtomic Emission SpectrometryD7582 Test Methods for Proximate Analysis of Coal andCoke by Macro Thermogravimetric Analysis3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 The critical temperature points to be observed are asfollows:3.1.2 fluid temperature, FTthe temperatu
10、re at which thefused mass has spread out in a nearly flat layer with amaximum height of 1.6 mm 116 in. as shown by the fifthcone, FT, in Fig. 1.3.1.3 hemispherical temperature, HTthe temperature atwhich the cone has fused down to a hemispherical lump atwhich point the height is one half the width of
11、 the base asshown by the fourth cone, HT, in Fig. 1.3.1.4 initial deformation temperature, ITthe temperatureat which the first rounding of the apex of the cone occurs.Shrinkage or warping of the cone ignored if the tip remainssharp. In Fig. 1, the first cone shown is an unheated one; thesecond cone
12、IT is a typical cone at the initial deformation stage.3.1.5 softening temperature, 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. 1.4. Summary of Test Method4.1 Coal or coke ash, prepar
13、ed by prescribed methods, ismixed with a small amount of a dextrin solution to form aplastic mass. A cone mold is used to form triangular pyramidswith the plastic mass, which are dried and mounted on aceramic platform. The cones and platform are rapidly heated inan electric furnace to 400 C (750 F).
14、 The cones and platformare then heated at a rate of 8 C 6 3 C 15 F 6 5 F min in1This test method is under the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct responsibility of D05.21 on Methods of Analysis.Current edition approved Feb. 1, 2017. Published February 2017. Originall
15、yapproved 1961. Last previous edition approved in 2016 as D1857 16. DOI:10.1520/D1857-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summ
16、ary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles
17、 for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1a reducing (CO/CO2) atmosphere, or an oxidizing (air) atmo-sphere. The ash cones are carefully observed as they passthrough certain defined s
18、tages of melting and flow.5. Significance and Use5.1 The design of most coal combustion and coal conver-sion equipment anticipates that the ash either remain solid orassume some degree of fluidity, depending on the particulardesign. Ash fusibility temperatures help predict whether theash will perfor
19、m properly in the process for which the coal waschosen.5.2 Ash fusibility temperature values are used in variousequations to predict the slagging tendency of ashes.6. Apparatus6.1 FurnaceAn electric furnace conforming to the follow-ing requirements may be used:6.1.1 Capable of maintaining a uniform
20、temperature zone inwhich to heat the ash cones.6.1.2 Capable of maintaining the desired atmosphere sur-rounding the cones during heating. The composition of theatmosphere, reducing or oxidizing, shall be maintained withinthe limits specified in Section 7. The desired atmosphere is tobe obtained by m
21、eans of gases introduced into the heatingchamber. The furnace should be gas impervious.6.1.3 Capable of regulation so that the rate of temperaturerise shall be 8 C 6 3 C 15 F 6 5 F min.6.1.4 Providing means of observing the ash cones during theheating. Observation on the same horizontal plane as the
22、cone-support surface shall be possible.6.2 Cone MoldA commercially available cone mold, typi-cally brass or made from a corrosion-resistant material with alow coefficient of friction, as shown in Fig. 2. The cone shallbe 19 mm 34 in. in height and 6.4 mm 14 in. in width at eachside of the base, whic
23、h is an equilateral triangle.Asteel spatulawith a pointed tip, ground off to fit the cone depression in themold, is suitable for removal of the ash cone.6.3 Refractory Tray MoldA mold with flat top and bottomsurfaces to provide a refractory tray of suitable thickness tominimize warping.Asidemold not
24、 over 6.4 mm 14 in. high ofany convenient shape, placed on an iron plate so that the topsurface of the refractory mix can be struck off flat and parallelto the tray by means of a straight edge, is satisfactory. Legs notover3mm18 in. long may be provided on the corners of thecone tray by suitable hol
25、es bored in the iron base plate of themold.6.4 Readout DeviceA thermocouple of platinum andplatinum-rhodium, protected from the furnace gases by aglazed porcelain sheath, shall be used with an appropriatereadout device accurate and readable to within 5.5 C 10 F.The hot junction of the thermocouple s
26、hall touch the end of thesheath and shall be located in the center of the furnace andimmediately to the rear of the cones. The thermocoupleprotective sheath shall be checked periodically for cracks. Thethermocouple and its meter shall meet the requirements ofSection 10.7. Reagents and Materials7.1 A
27、sh-Cone Refractory TraysThe ash cones shall bemounted on refractory trays. These trays are commerciallyavailable, or can be prepared using a mixture of equal parts byweight of kaolin and alumina. Materials conforming to thefollowing requirements are to be used in preparing the refrac-tory trays:7.2
28、KaolinNF-grade powder passing a 75 m (U.S.A.Standard No. 200) sieve.7.3 Aluminum OxideReagent grade ignited powder pass-ing a 150 m (U.S.A. Standard No. 100) sieve.7.4 Dextrin Solutionclear, filtered (if necessary) 10 %solution of dextrin containing 0.1 % salicylic acid as apreservative.7.5 Mold Rel
29、ease Agentpetroleum jelly, thinned withkerosene (if necessary), or a non-silicon-based mold releaseagent.7.6 Gold Wire0.51 mm diameter (twenty-four gage) orlarger round wire of 99.98 % purity, but drawn from metal of99.99 % purity, and having a melting point of 1063 C1945 F.7.7 Nickel Wire0.51 mm di
30、ameter (twenty-four gage) orlarger round wire of CP nickel, 99.98 % pure, fully annealed,and having a melting point of 1452 C 2645 F.FIG. 1 Critical Temperature PointsInch-poundUnits,in.SI Units,mm14 6.434 19.1112 38.12 50.23 76.2FIG. 2 Brass Cone MoldD1857/D1857M 1728. Test Atmospheres8.1 Reducing
31、Atmosphere TestA regulated flow of gas ofthe nominal composition, volume fraction 60 % carbon mon-oxide and volume fraction 40 6 5 % carbon dioxide, shall bemaintained in the heating chamber throughout the test (Note 1)in the furnace. The gas stream shall be regulated by anyconvenient means to provi
32、de a measured flow of 1.3 to 1.5furnace volumes per minute.8.2 Cylinders of CO/CO2GasTo assure that the CO/CO2gas remains mixed, maintain the temperature of the cylinderabove the critical temperature at which CO2can liquefy andseparate.8.3 Oxidizing Atmosphere TestA regulated stream of airshall be m
33、aintained throughout the test in the furnace. The gasstream shall be regulated by any convenient means to providea measured flow of 1.3 to 1.5 furnace volumes per minute.9. Sample and Test Specimen Preparation9.1 Coal and CokePrepare the analysis sample in accor-dance with Practice D2013 for coal or
34、 Practice D346 for cokeby pulverizing the material to pass a 250 m (No. 60) U.S.A.standard sieve.9.2 Laboratory Ashing of Coal or Coke Analysis SamplePrepare the ash from a thoroughly mixed analysis sample ofcoal or coke (see 9.1). To facilitate the ashing process, spreadthe coal or coke in a layer
35、about 6 mm (14 in.) in depth in aporcelain, quartz, fused silica, or fireclay roasting dish. Placethe dish in a muffle furnace at ambient temperature and heatgradually so that the temperature reaches 500 C 6 10 C atthe end of 1 h. For coals, continue heating the sample until thetemperature rises fro
36、m 500 C 6 10 C to 750 C 6 15 C in1 h. For cokes, continue heating the sample until the tempera-ture rises from 500 C 6 10 C to 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 constant mass or for anadditional2h(Note 1). Allow the dish t
37、o cool, transfer to anagate 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 for112 h to ensure complete and uniform oxidation of the ash.9.2.1 The two-stage ashing procedure allows pyritic sulfurto be oxidized and sulfur oxides expelled be
38、fore most metalcarbonates are decomposed. An ample supply of air in themuffle furnace must be assured at all times to ensure completeoxidation of the pyritic sulfur and, more importantly, toefficiently remove the SO2formed. Because of the possibilityof SO2product being absorbed by alkali and alkalin
39、e earthmetal oxides (especially CaO), it is advisable to not ash highpyritic sulfur coals with coals that have high alkali or alkalineearth metal contents, or both.NOTE 1The D3174 and D7582 ashing procedures used in thedetermination of ash from coal and/or coke samples and the D3682,D4326, and D6349
40、 ashing procedures used in preparing ash from coal orcoke samples, or both, for major and minor element analysis areacceptable procedures for preparing ash for the fusibility test.NOTE 2Amechanical agate mortar grinder will save time where manydeterminations are made.9.3 Preparation of ConesThorough
41、ly mix the ignited ashin a mechanical mixer or on a sheet of glazed paper or oil clothby raising first one corner to roll the ash over and then raisingeach of the other corners in rotation in the same manner untileach corner has been raised five times or more.9.3.1 Take sufficient ash for the number
42、 of cones desiredfrom various parts of the bulk ash. Moisten the ash with a fewdrops of a dextrin solution and work it into a stiff plastic masswith a spatula. Press the plastic material firmly with a spatulainto the cone mold to form the triangular pyramids. Strike offthe exposed surfaces of the ma
43、terial smooth and remove thecones from the mold by applying slight pressure at the basewith a suitably pointed spatula. Previous coating of the moldwith a very thin layer of petroleum jelly, thinned with kerosene(if necessary), or a very thin coating of a non-silicon-basedmold release agent, aids in
44、 preventing adherence of the conesto the mold and in providing the sharp point and edges desiredin the cone. With certain coal ashes, cones with sharp pointsand edges can be obtained using distilled water in place of thedextrin solution and without the use of petroleum jelly.9.3.2 Place the cones in
45、 a suitable location to dry sufficientlyto permit handling without deformation. Mount the dried conesvertically on a refractory tray.9.3.2.1 Follow the manufacturers recommendations formounting the dry cones on commercially available supporttrays.9.3.2.2 To prepare fresh support trays, moisten a por
46、tion ofthe well-mixed kaolin-alumina mixture with the minimumamount of water to make a workable, but stiff, plastic mass,and firmly press it into the support mold (Section 7.4). Strikeoff the surface of the mass flat and smooth with a steel spatula,moistening with one or two drops of water if necess
47、ary toobtain a smooth surface. A number of cones may be mountedon one base. Make shallow triangular depressions, not over0.8 mm 132 in. in depth, with a triangular file ground to thecorrect size to produce a depression to fit the base of the cone,and locate the cones sufficiently distant from adjace
48、nt cones sothat no merging of the fusing material of the cones shall occurduring the test. Mount the cones vertically in the depressionswhile the base is still wet without the use of ash or refractoryas a mounting aid (Note 3 and Note 4).NOTE 3The intent of the triangular depression is to enable the
49、 conesto be mounted in a sufficiently stable manner to permit handling of theprepared support with cones.NOTE 4Gold wires can be mounted on each cone support beside theash cones, and the gold melting point observed concurrent with the ashcones in both oxidizing and reducing atmospheres.9.4 Before running the test in a reducing atmosphere, drythe mounted cones and ignite (750 C) for 1 h to remove allcarbonaceous material. If no organic material has been used inthe preparation of the mount
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