1、Designation: D1857/D1857M 17D1857/D1857M 17aStandard 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 and health practices and determine the applicability of regulatorylimitations prior to use.1.5 This international standard was developed in accordance with i
7、nternationally 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 Documents2.1 ASTM Standards:2D34
8、6 Practice for Collection and Preparation of Coke Samples for Laboratory AnalysisD2013 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 Coke Analyses from As-Determined to Different Base
9、sD3682 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 Elements in Coal, Coke, and Solid Residues from Combus
10、tion 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 Coal and Coke by Macro Thermogravimetric Analysis3
11、. 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 maximumheight of 1.6 mm 116 in. as shown by the fifth co
12、ne, 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 Feb. 1, 2017Aug. 1, 2017. Published February 2017August 2017. Originally approved 1961. Last previous editi
13、on approved in 20162017 asD1857 16.D1857 17. DOI: 10.1520/D1857-17.10.1520/D1857-17a.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary p
14、age 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 to adequately depict all changes accurately, ASTM recommends that
15、 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 Conshohocken, PA 19428-2959. United States13.1.3 hemispherical temp
16、erature, HTthe temperature at which the cone has fused down to a hemispherical lump at whichpoint the height is one half the width of the base as shown by the fourth cone, HT, in Fig. 1.3.1.4 initial deformation temperature, ITthe temperature at which the first rounding of the apex of the cone occur
17、s. 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 IT isa typical cone at the initial deformation stage.3.1.5 softening temperature, STthe temperature at which the cone has fused down to a spherical lump in which t
18、he 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 form a plastic mass.A cone mold is used to form triangular pyramids with the plast
19、ic 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). The cones and platform are then heated at a rateof 8 C 6 3 C 15 F 6 5 Fmin in a reducing (CO/CO2) atmosphere, or an oxidizing (air) atmosphere. The ash cones
20、arecarefully 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 remain solid or assumesome degree of fluidity, depending on the particular design. Ash fus
21、ibility 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 tendency of ashes.6. Apparatus6.1 FurnaceAn electric furnace conforming to the following req
22、uirements 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 composition of the atmosphere,reducing or oxidizing, shall be maintained within the limits specif
23、ied 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 rise shall be 8 C 6 3 C 15 F 6 5 Fmin.6.1.4 Providing means of observing the ash cones dur
24、ing 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 with a lowcoefficient of friction, as shown in Fig. 2. The cone shall be 19 mm 34 in. in
25、 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 ash cone.6.3 Refractory Tray MoldA mold with flat top and bottom surfaces to provide a re
26、fractory 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 and parallel to the tray by means of a straight edge, is satisfactory. Legs not over 3 mm1
27、8 in. long may be provided on the corners of the cone tray by suitable holes bored in the iron base plate of the mold.6.4 Readout DeviceTemperature Measuring InstrumentA type R or S thermocouple of platinum and platinum-rhodium,protected from the furnace gases by a glazed porcelain sheath, shall be
28、used with an appropriate readout device accurate andreadable to within a display readable to better than 5.5 C 10 F. The hot junction of the thermocouple shall touch the end of thesheath and shall be located in the center of the furnace and immediately to the rear of the cones. The thermocouple prot
29、ectivesheath shall be checked periodically for cracks. The thermocouple and its meter shall meet the requirements of for cracks whenthere is difficulty in achieving the requirements outlined in Section 10.7. Reagents and Materials7.1 Ash-Cone Refractory TraysThe ash cones shall be mounted on refract
30、ory trays. These trays are commercially available,or can be prepared 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 17a27.2 KaolinNF-grad
31、e powder passing a 75 m (U.S.A. Standard No. 200) sieve.7.3 Aluminum OxideReagent grade ignited powder passing 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 a preservative.7.5 Mold Release Agentp
32、etroleum jelly, thinned with kerosene (if necessary), or a non-silicon-based mold release agent.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 1063 C 1945 F.1064 C 1948 F.37.7 Nickel Wire0.
33、51 mm diameter (twenty-four gage) or larger round wire of CP nickel, 99.98 % pure, fully annealed, andhaving a melting point of 1452 C 2645 F.1455 C 2651 F.38. Test Atmospheres8.1 Reducing Atmosphere TestA regulated flow of gas of the nominal composition, volume fraction 60 % carbon monoxideand volu
34、me fraction 4040 % 6 5 % 5 % carbon dioxide, shall be maintained in the heating chamber throughout the test (Note 1)in the furnace.The gas stream shall be regulated by any convenient means to provide a measured flow of 1.3 to 1.5 furnace volumesper minute.8.2 Cylinders of CO/CO2 GasTo assure that th
35、e CO/CO2 gas remains mixed, maintain the temperature of the cylinder abovethe 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 me
36、ans to provide a 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 accordance with Practice D2013 for coal or Practice D346 for coke bypulverizing the material to pass a 250 m (No. 60) U.S.A. standard sieve.9
37、.2 Laboratory Ashing of Coal or Coke Analysis 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 depth in a porcelain, quartz,fused silica, or fireclay roasting dish. Plac
38、e the dish in a muffle furnace at ambient temperature and heat gradually so that thetemperature 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 tempera
39、ture rises from 500 C 6 10 Cto 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 constant3 These temperatures are consistent with the ITS-90 temperature scale.Inch-poundUnits,in.SI Units,mm14 6.434 19.1112 38.12 50.23 76.2FIG. 2 Brass C
40、one MoldD1857/D1857M 17a3mass 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
41、 ashing procedure allows pyritic sulfur to be oxidized and sulfur oxides expelled before most metalcarbonates are decomposed.An ample supply of air in the muffle furnace must be assured at all times to ensure complete oxidationof the pyritic sulfur and, more importantly, to efficiently remove the SO
42、2 formed. Because of the possibility of SO2 product beingabsorbed by alkali and alkaline earth metal oxides (especially CaO), it is advisable to not ash high pyritic sulfur coals with coalsthat have high alkali or alkaline earth metal contents, or both.NOTE 1The D3174 and D7582 ashing procedures use
43、d in the determination 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 mort
44、ar grinder will save 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 mann
45、er until each cornerhas 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 sp
46、atula into thecone mold 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 wi
47、th kerosene (if necessary), 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
48、 water in place of the 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 th
49、e dry cones on commercially 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
