1、Designation: C492 92 (Reapproved 2017)1Standard Test Method forHydration of Granular Dead-Burned Refractory Dolomite1This standard is issued under the fixed designation C492; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 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.1NOTEFootnote 3 was removed editorially in November 2017.1. Scope1.1 This test method covers the determination of the amountof
3、 hydration of a granular dead-burned refractory dolomitewhen exposed to moist air.1.2 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.1.3 This standard does not purport to address all of thesafety concerns, if any, asso
4、ciated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally re
5、cognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C92 Test Methods f
6、or Sieve Analysis and Water Content ofRefractory MaterialsE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3. Significance and Use3.1 The hydration of dead-burned dolomite grains is animportant aspect of both manufacturing and using such grains.Moisture from any source will cause the
7、grains to partiallydisintegrate, eventually making the dead-burned dolomite unfitfor use. This test method may prove useful for determining, ina relative manner, which grains are more resistant to hydrationthan others.3.2 Data from one laboratory might help in establishinginternal limits for determi
8、ning whether a particular batch ofgrain is suitable for refractory production. However, this testmethod takes great care to run, and is not recommended as aquality control test. Possibly, a specification might be devel-oped between two parties if sufficient care in establishing thebias between the l
9、aboratories is carried out.4. Apparatus4.1 Sieve, ASTM No. 40 (425-m) conforming to Specifi-cation E11, with pan and cover.4.2 Glass Petri Dishes, 95 by 20-mm.4.3 Circulating Hot-Air Oven, capable of operating at 220 to230 F (104 to 110 C).4.4 Steam-Humidity Cabinet, to be maintained at 160 62 F (71
10、 6 1 C) and 85 6 3 % humidity.4.5 Scale, having a capacity of 200 g, accurate to 0.02 g.5. Sampling5.1 The sample used shall be quartered or riffled so that it istypical of the material being tested both in screen size andoiling. All material passing the No. 40 (425-m) sieve shall beremoved from thi
11、s sample by screening. All screening shall bedone in accordance with Test Methods C92 for dry sieveanalysis.6. Procedure6.1 Place a 100 6 0.1-g portion of the representative sampleretained on the No. 40 (425-m) sieve sample in a 95 by20-mm Petri dish. Then place this dish in a hot-air oven for12 h a
12、t 220 to 230 F (104 to 110 C) to prevent condensationof water on the sample when placed in a hot steam-humiditycabinet.6.2 Transfer the Petri dish containing the sample from thehot-air oven to the steam-humidity cabinet, and cover with aglass plate at an angle of 45 to prevent dripping on the sample
13、.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 Nov. 1, 2017. Published November 2017. Originallyapproved in 1962. Last previous edition approved in 2017 as C492 92
14、 (2017).DOI: 10.1520/C0492-92R17E01.2For 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.This international standa
15、rd was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1The edg
16、es of the glass plate shall overhang the Petri dish byabout34 in. (19 mm).6.3 Maintain the steam-humidity cabinet at 160 6 2 F (716 1 C) and 85 6 3 % humidity for 24 h. The time to reachthese conditions shall be approximately12 h. Then immedi-ately remove the Petri dish from the cabinet and place in
17、 ahot-air oven at 220 to 230 F (104 to 110 C) for12 h or untila constant weight is attained. Then screen the sample on a No.40 (425-m) sieve and weigh the material passing the sieve tothe nearest 0.1 g. Always run the tests in triplicate.7. Report7.1 Report the hydration of a sample as the average p
18、ercent-age of material passing the No. 40 (425-m) sieve after thehydration test.8. Precision and Bias8.1 Interlaboratory Study:8.1.1 An interlaboratory test program between four labora-tories was conducted. Each laboratory tested three dolomiticmaterials. Each of the three dolomitic materials was te
19、sted fourtimes.8.1.2 No ruggedness test was run on this test method priorto conducting the interlaboratory study.8.2 Precision:8.2.1 RepeatabilityThe maximum permissible differencedue to test error between two test results obtained by oneoperator on the same material is given by the repeatabilityint
20、erval and the relative repeatability interval (coefficient ofvariation). The 95 % repeatability intervals are given in Table1. 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
21、 bymore than the repeatability interval will be considered to befrom different populations.8.2.2 ReproducibilityThe maximum 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 eq
22、uipment is given by thereproducibility interval and relative reproducibility interval(coefficient of variation). The 95 % reproducibility intervalsare given in Table 1. Two test results that do not differ by morethan the reproducibility interval will be considered to be fromthe same population, and,
23、 conversely, two test results that dodiffer by more than the reproducibility interval will be consid-ered to be from different populations.8.3 BiasThis test method does not lend itself to a state-ment of bias.9. Keywords9.1 dolomite; grain; humidity cabinet; hydration resistance;refractoriesASTM Int
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29、ialNumberAverage, XStandardWithin, SrDeviationBetween, SRRepeatabilityInterval, rReproducibilityIntervalCoefficient of VariationRelativeRepeatability,% rRelativeReproducibility,% RWithin Lab,VrBetween Labs,VR1 23.94 0.8752 1.513 2.450 4.236 3.656 6.320 10.23 17.692 4.820 0.2325 0.5299 0.6510 1.484 4.824 10.99 13.51 30.793 3.645 0.1355 0.3007 0.3795 0.8419 3.717 8.250 10.41 23.10C492 92 (2017)12
