ASTM C492-92(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: C492 − 92 (Reapproved 2023)
Standard Test Method for
Hydration of Granular Dead-Burned Refractory Dolomite
This standard is issued under the fixed designation C492; 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 3.2 Data from one laboratory might help in establishing
internal limits for determining whether a particular batch of
1.1 This test method covers the determination of the amount
grain is suitable for refractory production. However, this test
of hydration of a granular dead-burned refractory dolomite
method takes great care to run, and is not recommended as a
when exposed to moist air.
quality control test. Possibly, a specification might be devel-
1.2 The values stated in inch-pound units are to be regarded
oped between two parties if sufficient care in establishing the
as the standard. The values given in parentheses are for
bias between the laboratories is carried out.
information only.
4. Apparatus
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4.1 Sieve, ASTM No. 40 (425 μm) conforming to Specifi-
responsibility of the user of this standard to establish appro-
cation E11, with pan and cover.
priate safety, health, and environmental practices and deter-
4.2 Glass Petri Dishes, 95 mm by 20 mm.
mine the applicability of regulatory limitations prior to use.
4.3 Circulating Hot-Air Oven, capable of operating at
1.4 This international standard was developed in accor-
220 °F to 230 °F (104 °C to 110 °C).
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4.4 Steam-Humidity Cabinet, to be maintained at 160 °F 6
Development of International Standards, Guides and Recom-
2 °F (71 °C 6 1 °C) and 85 % 6 3 % humidity.
mendations issued by the World Trade Organization Technical
4.5 Scale, having a capacity of 200 g, accurate to 0.02 g.
Barriers to Trade (TBT) Committee.
5. Sampling
2. Referenced Documents
2 5.1 The sample used shall be quartered or riffled so that it is
2.1 ASTM Standards:
typical of the material being tested both in screen size and
C92 Test Methods for Sieve Analysis and Water Content of
oiling. All material passing the No. 40 (425 μm) sieve shall be
Refractory Materials
removed from this sample by screening. All screening shall be
E11 Specification for Woven Wire Test Sieve Cloth and Test
done in accordance with Test Methods C92 for dry sieve
Sieves
analysis.
3. Significance and Use
6. Procedure
3.1 The hydration of dead-burned dolomite grains is an
6.1 Place a 100 g 6 0.1 g portion of the representative
important aspect of both manufacturing and using such grains.
sample retained on the No. 40 (425 μm) sieve sample in a
Moisture from any source will cause the grains to partially
95 mm by 20 mm Petri dish. Then place this dish in a hot-air
disintegrate, eventually making the dead-burned dolomite unfit
oven for ⁄2 h at 220 °F to 230 °F (104 °C to 110 °C) to prevent
for use. This test method may prove useful for determining, in
condensation of water on the sample when placed in a hot
a relative manner, which grains are more resistant to hydration
steam-humidity cabinet.
than others.
6.2 Transfer the Petri dish containing the sample from the
hot-air oven to the steam-humidity cabinet, and cover with a
This test method is under the jurisdiction of ASTM Committee C08 on
glass plate at an angle of 45° to prevent dripping on the sample.
Refractories and is the direct responsibility of Subcommittee C08.04 on Chemical
Behaviors.
The edges of the glass plate shall overhang the Petri dish by
Current edition approved Nov. 1, 2023. Published November 2023. Originally
about ⁄4 in. (19 mm).
ɛ1
approved in 1962. Last previous edition approved in 2017 as C492 – 92 (2017) .
DOI: 10.1520/C0492-92R23.
6.3 Maintain the steam-humidity cabinet at 160 °F 6 2 °F
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
(71 °C 6 1 °C) and 85 % 6 3 % humidity for 24 h. The time
contact ASTM Customer Service at
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