ASTM_C_544_-_03_2013.pdf

Designation:C54403(Reapproved 2013)Standard 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,the 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 relativeresistance of magnesia grain to hydration.1.2 This standard 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 ASTM Standards:2C92 Test Methods for Sieve Analysis and Water Content ofRefractory MaterialsC357 Test Method for Bulk Density of Granular RefractoryMaterialsC456 Test Method for Hydration Resistance of Basic Bricksand ShapesC493 Test Method for Bulk Density and Porosity of Granu-lar Refractory Materials by Mercury Displacement(Dis-continued 2002)(Withdrawn 2002)33.Significance and Use3.1 This test method determines relative hydration resis-tance of magnesia grain.3.2 This test method is used in industry to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 interpreting 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.NOTE1A suitable apparatus is shown in Fig.1 of Test Method C456.4.2 Standard Sieves,ASTM No.6(3.35 mm),No.12(1.70mm),No.20(850 m),No.40(425 m),and No.50(300 m).NOTE2The equivalent Tyler Standard Series sieves described in TestMethods C92 may 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 obtain 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.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,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)for at least 2 h.5.6 Place the preheated rack containing the specimens 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 autoclave 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 and 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.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 April 1,2013.Published August 2013.Originallyapproved in 1964.Last previous edition approved in 2008 as C544 03(2008).DOI:10.1520/C0544-03R13.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 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 retainedon the No.50 sieve.Record the individual specimen weight,H.6.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 thepercentage o