1、Designation: C 544 03 (Reapproved 2008)Standard Test Method forHydration of Dead Burned Magnesite or Periclase Grain1This standard is issued under the fixed designation C 544; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the measurement of the relativeresistance of magnesia grain to hydration.1.2 This standa
3、rd 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 and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 AST
4、M Standards:2C92 Test Methods for Sieve Analysis and Water Content ofRefractory MaterialsC 357 Test Method for Bulk Density of Granular RefractoryMaterialsC 456 Test Method for Hydration Resistance of BasicBricks and ShapesC 493 Test Method for Bulk Density and Porosity of Granu-lar Refractory Mater
5、ials by Mercury Displacement (Dis-continued 2002)33. Significance and Use3.1 This test method determines relative hydration resis-tance of magnesia grain.3.2 This test method is used in industry to evaluate grainsamples and is used for specification purposes in some cases.3.3 Care must be taken in i
6、nterpreting the data.4. Apparatus4.1 Autoclave, suitable for operation at 80 psi (552 kPa) at324F (162C) and equipped with pressure- and temperature-measuring devices and safety equipment.NOTE 1A suitable apparatus is shown in Fig. 1 of Test Method C 456.4.2 Standard Sieves, ASTM No. 6 (3.35 mm), No
7、. 12 (1.70mm), No. 20 (850 m), No. 40 (425 m), and No. 50 (300 m).NOTE 2The equivalent Tyler Standard Series sieves described in TestMethods C92may be substituted for the ASTM sieves.5. Procedure5.1 Remove the material retained on a No. 6 (3.35-mm)sieve, and crush it to pass the No. 6 sieve to obtai
8、n themaximum amount of coarse material. Recombine with theportion passing the No. 6 sieve, and screen the resultant sampleto remove all material passing a No. 40 (425-m) sieve. Ifnecessary, dry at 220 to 230F (105 to 110C).5.2 Separate this sample into the following three fractions:Passing Sieve No.
9、 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 byweight of the three sizes listed in 5.2.5.4 Add sufficient water to the autoclave to maintain 80 psi(552 kPa) at 324F (162C) for the duration of each 5-h test
10、,but not enough to permit contact with any of the specimens.5.5 Place each weighed specimen in a No. 3 porcelaincrucible, and cover with a loosely crimped piece of aluminumfoil to protect the specimen from drip or condensate. Dry thecovered crucibles in a forced-air dryer at 220 to 230F (105 to110C)
11、 for at least 2 h.1This test method is under the jurisdiction of ASTM Committee C08 onRefractories and is the direct responsibility of Subcommittee C08.04 on ChemicalBehaviors.Current edition approved March 1, 2008. Published March 2008. Originallyapproved in 1964. Last previous edition approved in
12、2003 as C 544 03.2For 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 Summary page onthe ASTM website.3Withdrawn.TABLE 1 Material PropertiesMateri
13、al Number 1234Chemical 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 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
14、100.0 99.9Bulk Specific Gravity:By Water Displacement(ASTM C 357). . . . . . 3.21 3.32By Mercury Displacement(ASTM C 493)3.36 3.15 3.27 3.371Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.6 Place the preheated rack containing the s
15、pecimens in theautoclave. Heat the autoclave with the pressure-release valveopen; after a steady flow of steam is obtained through thevalve, continue to purge for 3 min to remove all air, close thevalve, and bring the autoclave to 80 psi (552 kPa) at 324F(162C) in a total time of 1 h. Maintain the a
16、utoclave at 80 65 psi (552 6 35 kPa) and 324 6 4F (162 6 2C) for 5 h.5.7 Allow sufficient cooling to lower the autoclave to 20 to30 psi (138 to 207 kPa) with the release valve closed, and thencarefully open the relief valve to reduce the autoclave toatmospheric pressure in a total time between 30 an
17、d 60 min.Remove the specimens and dry to constant weight at 220 to230F (105 to 110C) in a forced-air dryer. Record theindividual 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 a
18、mount of material retainedon the No. 50 sieve. Record the individual specimen weight, H.6. Calculation and Report6.1 Calculate the percentage hydration as follows:hydration, % 5 G 2 H!/G# 3 100where:G = weight of dried specimen after hydration, g, andH = weight of hydrated specimen retained on a No.
19、 50(300-m) sieve, g.6.2 Report the amount of hydration of each specimen as thepercentage of material passing the No. 50 (300-m) sieve afterthe hydration test.7. Precision and Bias7.1 Interlaboratory Study:7.1.1 An interlaboratory test program between six laborato-ries was conducted. Each laboratory
20、tested four magnesiamaterials. Each of the four magnesia materials was tested fourtimes. Typical chemical analyses and bulk specific gravity dataon the four magnesia materials appear in Table 1.47.1.2 No ruggedness test was run on this test method priorto conducting the interlaboratory study.7.2 Pre
21、cision:7.2.1 RepeatabilityThe maximum permissible differencedue to test error between two test results obtained by oneoperator on the same material is given by the repeatabilityinterval and the relative repeatability interval (coefficient ofvariation). The 95 % repeatability intervals are given in T
22、able2. Two test results that do not differ by more than therepeatability interval will be considered to be from the samepopulation, and, conversely, two test results that do differ bymore than the repeatability interval will be considered to befrom different populations.7.2.2 ReproducibilityThe maxi
23、mum permissible differ-ence due to test error between two test results obtained by twooperators in different laboratories on the same type of materialusing the same type of test equipment is given by thereproducibility interval and relative reproducibility interval(coefficient of variation). The 95
24、% reproducibility intervalsare given in Table 2. Two test results that do not differ by morethan the reproducibility interval will be considered to be fromthe same population, and, conversely, two test results that dodiffer by more than the reproducibility interval will be consid-ered to be from dif
25、ferent populations.7.3 BiasThis test method does not lend itself to a state-ment of bias.8. Keywords8.1 autoclave; grain; hydration resistance; magnesite; peri-clase; refractoriesASTM International takes no position respecting the validity of any patent rights asserted in connection with any item me
26、ntionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committe
27、e and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeti
28、ng of theresponsible technical committee, 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
29、 Box C700, West Conshohocken, PA 19428-2959,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).4T
30、hese data were not measured on the actual samples tested in the hydration test,but are representative of the materials used in the interlaboratory study.TABLE 2 Repeatability and Reproducibility DataMaterialNumberAverage, XStandardWithin, SrDeviationBetween, SRRepeatabilityInterval, rReproducibility
31、Interval, RCoefficient of Variation RelativeRepeatability,% rRelativeReproducibility,% RWithin Lab,VrBetween 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 32.92C 544 03 (2008)2
