1、Designation: C544 03 (Reapproved 2017)C544 18Standard Test Method forHydration of Dead-Burned Magnesite or Periclase Grain1This standard is issued under the fixed designation C544; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e 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 measurement of the relative resistance of magnesia grain to hydration.1.2 This s
3、tandard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability ofregulatory limitations prior to use.1.3 This in
4、ternational standard was developed 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) C
5、ommittee.2. Referenced Documents2.1 ASTM Standards:2C92 Test Methods for Sieve Analysis and Water Content of Refractory MaterialsC357 Test Method for Bulk Density of Granular Refractory MaterialsC456 Test Method for Hydration Resistance of Basic Bricks and ShapesC493 Test Method for Bulk Density and
6、 Porosity of Granular Refractory Materials by Mercury Displacement (Discontinued2002) (Withdrawn 2002)33. Significance and Use3.1 This test method determines relative hydration resistance of magnesia grain.3.2 This test method is used in industry to evaluate grain samples and is used for specificati
7、on purposes in some cases.3.3 Care must be taken in interpreting the data.4. Apparatus4.1 Autoclave, suitable for operation at 80 psi (552 kPa) at 324 F (162 C) and equipped with pressure and temperaturemeasuring devices and safety equipment.NOTE 1A suitable apparatus is shown in Fig. 1 of Test Meth
8、od C456.4.2 Standard Sieves, ASTM No. 6 (3.35 mm), No. 12 (1.70 mm), No. 20 (850 m), No. 40 (425 m), and No. 50 (300 m).NOTE 2The equivalent Tyler Standard Series sieves described in Test Methods C92 may be substituted for the ASTM sieves.5. Procedure5.1 Remove the material retained on a No. 6 (3.35
9、-mm) sieve, and crush it to pass the No. 6 sieve to obtain the maximumamount of coarse material. Recombine with the portion passing the No. 6 sieve, and screen the resultant sample to remove allmaterial passing a No. 40 (425-m) sieve. If necessary, dry at 220 to 230 F (105 to 110 C).5.2 Separate thi
10、s sample into the following three fractions:1 This test method is under the jurisdiction of ASTM Committee C08 on Refractories and is the direct responsibility of Subcommittee C08.04 on Chemical Behaviors.Current edition approved Nov. 1, 2017Feb. 1, 2018. Published November 2017February 2018. Origin
11、ally approved in 1964. Last previous edition approved in 20132017as C544 03 (2013).(2017). DOI: 10.1520/C0544-03R17.10.1520/C0544-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. ForAnnual Book ofASTM Standardsvolume informat
12、ion, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.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
13、to the previous version. Becauseit may not be technically possible to 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.Copyri
14、ght ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1Passing Sieve No. Retained on Sieve No.6 (3.35 mm) 12 (1.70 mm)12 (1.70 mm) 20 (850 m)20 (850 m) 40 (425 m)5.3 Prepare a 100-g specimen by using equal parts by weight of the three sizes listed
15、 in 5.2.5.4 Add sufficient water to the autoclave to maintain 80 psi (552 kPa) at 324 F (162 C) for the duration of each 5-h test, butnot enough to permit contact with any of the specimens.5.5 Place each weighed specimen in a No. 3 porcelain crucible, and cover with a loosely crimped piece of alumin
16、um foil toprotect the specimen from drip or condensate. Dry the covered crucibles in a forced-air dryer at 220 to 230 F (105 to 110 C) forat least 2 h.5.6 Place the preheated rack containing the specimens in the autoclave. Heat the autoclave with the pressure-release valve open;after a steady flow o
17、f steam is obtained through the valve, continue to purge for 3 min to remove all air, close the valve, and bringthe autoclave to 80 psi (552 kPa) at 324 F (162 C) in a total time of 1 h. Maintain the autoclave at 80 6 5 psi (552 6 35 kPa)and 324 6 4 F (162 6 2 C) for 5 h.5.7 Allow sufficient cooling
18、 to lower the autoclave to 20 to 30 psi (138 to 207 kPa) with the release valve closed, and thencarefully open the relief valve to reduce the autoclave to atmospheric pressure in a total time between 30 and 60 min. Remove thespecimens and dry to constant weight at 220 to 230 F (105 to 110 C) in a fo
19、rced-air dryer. Record the individual specimen weight,G.5.8 Place each specimen with the cover and the pan on a No. 50 (300-m) sieve, and screen according to Test Methods C92for dry sieve analysis. Weigh the amount of material retained on the No. 50 sieve. Record the individual specimen weight, H.6.
20、 Calculation and Report6.1 Calculate the percentage hydration as follows:hydration,%5G 2 H!/G#3100where:G = weight of dried specimen after hydration, g, andH = weight of hydrated specimen retained on a No. 50 (300-m) sieve, g.6.2 Report the amount of hydration of each specimen as the percentage of m
21、aterial passing the No. 50 (300-m) sieve after thehydration test.7. Precision and Bias7.1 Interlaboratory Study:7.1.1 An interlaboratory test program betweenamong six laboratories was conducted. Each laboratory tested four magnesiamaterials. Each of the four magnesia materials was tested four times.
22、 Typical chemical analyses and bulk specific gravity data onthe four magnesia materials appear in Table 1.47.1.2 No ruggedness test was run on this test method prior to conducting the interlaboratory study.7.2 Precision:7.2.1 RepeatabilityThe maximum permissible difference due to test error between
23、two test results obtained by one operatoron the same material is given by the repeatability interval and the relative repeatability interval (coefficient of variation). The 95 %repeatability intervals are given in Table 2. Two test results that do not differ by more than the repeatability interval w
24、ill beconsidered to be from the same population, and, conversely, two test results that do differ by more than the repeatability intervalwill be considered to be from different populations.4 These data were not measured on the actual samples tested in the hydration test, but are representative of th
25、e materials used in the interlaboratory study.TABLE 2 Repeatability and Reproducibility DataMaterialNumber Average, XStandardWithin, SrDeviationBetween, SRRepeatabilityInterval, rReproducibilityInterval, RCoefficient of Variation RelativeRepeatability,% rRelativeReproducibility,% RWithin Lab,VrBetwe
26、en Labs,VR1 63.61 2.818 4.447 7.891 12.45 4.430 6.991 12.41 19.572 37.06 3.082 3.811 8.628 10.67 8.316 10.28 23.28 28.793 21.04 3.108 5.947 8.703 16.65 14.77 28.27 41.36 79.134 60.27 6.254 7.085 17.51 19.84 10.38 11.76 29.05 32.92C544 1827.2.2 ReproducibilityThe maximum permissible difference due to
27、 test error between two test results obtained by two operatorsin different laboratories on the same type of material using the same type of test equipment is given by the reproducibility intervaland relative reproducibility interval (coefficient of variation). The 95 % reproducibility intervals are
28、given in Table 2. Two testresults that do not differ by more than the reproducibility interval will be considered to be from the same population, and,conversely, two test results that do differ by more than the reproducibility interval will be considered to be from differentpopulations.7.3 BiasThis
29、test method does not lend itself to a statement of bias.8. Keywords8.1 autoclave; grain; hydration resistance; magnesite; periclase; refractoriesASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of
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32、ittee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19
33、428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the s
34、tandard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 1 Material PropertiesMaterial Number 1 2 3 4Chemical Analysis (CalcinedBasis), %:Silica (SiO2) 1.0 3.3 0.7 0.55Alumina (Al2O3) 0.5 1.7 0.2 0.2Iron Oxide (Fe2O3) 0.5 3.8
35、0.2 0.2Chromic Oxide (Cr2O3) . . . 2.2 . . . . . .Lime (CaO) 3.0 11.0 0.7 2.2Boron Oxide (B2O3) . . . . . . 0.03 0.01Magnesia (MgO) 95.0 78.0 98.2 96.75Total, % 100.0 100.0 100.0 99.9Bulk Specific Gravity:By Water Displacement(ASTM C357). . . . . . 3.21 3.32By Water Displacement(Test Method C357). . . . . . 3.21 3.32By Mercury Displacement(ASTM C493)3.36 3.15 3.27 3.37By Mercury Displacement(Test Method C493)3.36 3.15 3.27 3.37C544 183
