ASTM C544-18(2023)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C544 − 18 (Reapproved 2023)
Standard Test Method for
Hydration of Dead-Burned Magnesite or Periclase Grain
This standard is issued under the fixed designation C544; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Significance and Use
3.1 This test method determines relative hydration resis-
1.1 This test method covers the measurement of the relative
tance of magnesia grain.
resistance of magnesia grain to hydration.
3.2 This test method is used in industry to evaluate grain
1.2 The values stated in inch-pound units are to be regarded
samples and is used for specification purposes in some cases.
as standard. The values given in parentheses are mathematical
3.3 Care must be taken in interpreting the data.
conversions to SI units that are provided for information only
and are not considered standard.
4. Apparatus
1.3 This standard does not purport to address all of the
4.1 Autoclave, suitable for operation at 80 psi (552 kPa) at
safety concerns, if any, associated with its use. It is the
324 °F (162 °C) and equipped with pressure and temperature
responsibility of the user of this standard to establish appro-
measuring devices and safety equipment.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
NOTE 1—A suitable apparatus is shown in Fig. 1 of Test Method C456.
1.4 This international standard was developed in accor-
4.2 Standard Sieves, ASTM No. 6 (3.35 mm), No. 12
dance with internationally recognized principles on standard-
(1.70 mm), No. 20 (850 μm), No. 40 (425 μm), and No. 50
ization established in the Decision on Principles for the
(300 μm).
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
5. Procedure
Barriers to Trade (TBT) Committee.
5.1 Remove the material retained on a No. 6 (3.3 mm) sieve,
and crush it to pass the No. 6 sieve to obtain the maximum
2. Referenced Documents
amount of coarse material. Recombine with the portion passing
2.1 ASTM Standards: the No. 6 sieve, and screen the resultant sample to remove all
C92 Test Methods for Sieve Analysis and Water Content of material passing a No. 40 (425 μm) sieve. If necessary, dry at
Refractory Materials 220 °F to 230 °F (105 °C to 110 °C).
C357 Test Method for Bulk Density of Granular Refractory
5.2 Separate this sample into the following three fractions:
Materials
Passing Sieve No. Retained on Sieve No.
C456 Test Method for Hydration Resistance of Basic Bricks
6 (3.35 mm) 12 (1.70 mm)
and Shapes 12 (1.70 mm) 20 (850 μm)
20 (850 μm) 40 (425 μm)
C493 Test Method for Bulk Density and Porosity of Granu-
5.3 Prepare a 100 g specimen by using equal parts by weight
lar Refractory Materials by Mercury Displacement (With-
of the three sizes listed in 5.2.
drawn 2002)
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,
but not enough to permit contact with any of the specimens.
This test method is under the jurisdiction of ASTM Committee C08 on
Refractories and is the direct responsibility of Subcommittee C08.04 on Chemical
5.5 Place each weighed specimen in a No. 3 porcelain
Behaviors.
crucible, and cover with a loosely crimped piece of aluminum
Current edition approved Nov. 1, 2023. Published November 2023. Originally
approved in 1964. Last previous edition approved in 2018 as C544 – 18. DOI:
foil to protect the specimen from drip or condensate. Dry the
10.1520/C0544-18R23.
covered crucibles in a forced-air dryer at 220 °F to 230 °F
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
(105 °C to 110 °C) for at least 2 h.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
5.6 Place the preheated rack containing the specimens in the
the ASTM website.
autoclave. Heat the autoclave with the pressure-release valve
The last approved version of this historical standard is referenced on
www.astm.org. open; after a steady flow of steam is obtained through the
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C544 − 18 (2023)
TABLE 1 Material Properties
valve, continue to purge for 3 min to remove all air, close the
valve, and bring the autoclave to 80 psi (552 kPa) at 324 °F Material Number 1 2 3 4
Chemical Analysis (Calcined
(162 °C) in a total time of 1 h. Maintain the autoclave at 80 psi
Basis), %:
6 5 psi (552 kPa 6 35 kPa) and 324 °F 6 4 °F (162 °C 6
Silica (SiO ) 1.0 3.3 0.7 0.55
2 °C) for 5 h. Alumina (Al O ) 0.5 1.7 0.2 0.2
2 3
Iron Oxide (Fe O ) 0.5 3.8 0.2 0.2
2 3
5.7 Allow sufficient cooling to lower the autoclave to 20 psi
Chromic Oxide (Cr O ) . . . 2.2 .
...