ASTM C24-01(2006)
(Test Method)Standard Test Method for Pyrometric Cone Equivalent (PCE) of Fireclay and High Alumina Refractory Materials
Standard Test Method for Pyrometric Cone Equivalent (PCE) of Fireclay and High Alumina Refractory Materials
SIGNIFICANCE AND USE
The deformation and end point of a cone corresponds to a certain heat-work condition due to the effects of time, temperature, and atmosphere.
The precision of this test method is subject to many variables that are difficult to control. Therefore, an experienced operator may be necessary where PCE values are being utilized for specification purposes.
PCE values are used to classify fireclay and high alumina refractories.
This is an effective method of identifying fireclay variations, mining control, and developing raw material specifications.
Although not recommended, this test method is sometimes applied to materials other than fireclay and high alumina. Such practice should be limited to in-house laboratories and never be used for specification purposes.
SCOPE
1.1 This test method covers the determination of the Pyrometric Cone Equivalent (PCE) of fire clay, fireclay brick, high alumina brick, and silica fire clay refractory mortar by comparison of test cones with standard pyrometric cones under the conditions prescribed in this test method.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are for information only.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:C 24–01 (Reapproved 2006)
Standard Test Method for
Pyrometric Cone Equivalent (PCE) of Fireclay and High
Alumina Refractory Materials
ThisstandardisissuedunderthefixeddesignationC24;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 4. Summary of Test Method
1.1 This test method covers the determination of the Pyro- 4.1 This test method consists of preparing a test cone from
metric Cone Equivalent (PCE) of fire clay, fireclay brick, high a refractory material and comparing its deformation end point
alumina brick, and silica fire clay refractory mortar by com- to that of a standard pyrometric cone. The resultant PCE value
parison of test cones with standard pyrometric cones under the is a measure of the refractoriness of the material.
conditions prescribed in this test method. 4.2 Temperature equivalent tables for the standard cones
1.2 The values stated in inch-pound units are to be regarded have been determined by the National Institute of Standards
as standard. The values given in parentheses are for informa- andTechnology when subjected to both slow and rapid heating
tion only. rates.
1.3 This standard does not purport to address all of the
5. Significance and Use
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 5.1 The deformation and end point of a cone corresponds to
a certain heat-work condition due to the effects of time,
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. temperature, and atmosphere.
5.2 The precision of this test method is subject to many
2. Referenced Documents
variables that are difficult to control.Therefore, an experienced
2.1 ASTM Standards: operatormaybenecessarywherePCEvaluesarebeingutilized
C71 Terminology Relating to Refractories for specification purposes.
E11 Specification for Wire Cloth and Sieves for Testing 5.3 PCE values are used to classify fireclay and high
Purposes alumina refractories.
E 220 Test Method for Calibration of Thermocouples By 5.4 This is an effective method of identifying fireclay
Comparison Techniques variations, mining control, and developing raw material speci-
E 691 Practice for Conducting an Interlaboratory Study to fications.
Determine the Precision of a Test Method 5.5 Although not recommended, this test method is some-
times applied to materials other than fireclay and high alumina.
3. Terminology
Such practice should be limited to in-house laboratories and
3.1 Definitions—For definitions of terms used in this test
never be used for specification purposes.
method, see TerminologyC71.
6. Procedure
6.1 Preparation of Sample:
This test method is under the jurisdiction of ASTM Committee C08 on
6.1.1 Clay or Brick—Crush the entire sample of fire clay or
Refractories and is the direct responsibility of Subcommittee C08.02 on Thermal
fireclay brick, in case the amount is small, by means of rolls or
Properties.
a jaw crusher to produce a particle size not larger than ⁄4 in. (6
Current edition approved March 1, 2006. Published March 2006. Originally
approved in 1919. Last previous edition approved in 2001 as C 24 – 01.
mm). If the amount is large, treat a representative sample
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
obtained by approved methods. Then mix the sample thor-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
oughly and reduce the amount to about 250 g (0.5 lb) by
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. quartering (see Note 1). Then grind this portion in an agate,
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C 24–01 (2006)
porcelain, or hard steel mortar and reduce the amount again by
quartering. The final size of the sample shall be 50 g and the
fineness capable of passing an ASTM No. 70 (212-µm) sieve
(equivalent to a 65-mesh Tyler Standard Series). In order to
avoid excessive reduction to fines, remove them frequently
during the process of reduction by throwing the sample on the
sieve and continuing the grinding of the coarser particles until
all the sample passes through the sieve (see Note 2). Take
precautions to prevent contamination of the sample by steel
particles from the sampling equipment during crushing or
grinding.
NOTE 1—Take care during the crushing and grinding of the sample to
prevent the introduction of magnetic material.
NOTE 2—The requirement to grind the coarser particles is particularly
important for highly siliceous products; excessively fine grinding may
reduce their PCE by as much as two cones.
6.1.2 Silica Fire Clay (see 3.1)—In the case of silica fire
clay, test the sample obtained by approved methods as received
without grinding or other treatment.
6.2 Preparation of Test Cones:
6.2.1 After preparing samples of unfired clays (Note 3), or
of mixes containing appreciable proportions of raw clay, in
accordance with 6.1.1, heat them in an oxidizing atmosphere in
NOTE 1—Dimensions are in inches.
the temperature range from 1700 to 1800°F (925 to 980°C) for
not less than 30 min.
SI Equivalents
NOTE 3—Someunfiredclaysbloatwhentheyareformedintoconesand
arecarriedthroughthehigh-temperatureheattreatmentprescribedin5.4.1
in. mm
without preliminary calcining. The substances that cause bloating can, in
0.075 1.90
most cases, be expelled by heating the clay samples before testing.
0.272 6.91
0.281 7.14
6.2.2 The clay sample may be given the heat treatment
1.081 27.46
prescribed in 6.2.1 after it has been formed into a cone (see
1.125 28.58
6.2.3), but this procedure has been found not as effective as the
FIG. 1 Standard Pyrometric Test Cone
treatment of the powdered material. If cones so prepared bloat
during the PCE test, heat a portion of the original sample in its
NOTE 4—A satisfactory cone plaque mix consists of 85 % fused
powdered condition as prescribed in 6.2.1 and then retest it.
alumina and 15 % plastic refractory clay. For tests that will not go above
6.2.3 Thoroughly mix the dried sample, and after the
Cone 34, the plastic refractory clay may be increased to 25 % and the
addition of sufficient dextrine, glue, gum tragacanth, or other
alumina may be replaced with brick grog containing over 70 % alumina.
alkali-free organic binder and water, form it in a metal mold
The alumina or grog should be ground to pass anASTM No. 60 (250-µm)
intotestconesintheshapeofatruncatedtrigonalpyramidwith
sieve (equivalent to a 60-mesh Tyler Standard Series), and the PCE of the
its base at a small angle to the trigonal axis, and in accordance refractory plastic clay should be not lower than Cone 32.
NOTE 5—The number of cones and their mounting facing inward as
with dimensions shown in Fig. 1. In forming the test cone use
shown in Fig. 3 is typical for gas-fired furnaces of relatively large
the mold shown in Fig. 2.
dimensions and gases moving at high velocity. The practical bore of the
6.3 Mounting:
muffle tubes in most electric furnaces does not permit cone pats of this
6.3.1 Mount both the test cones and the Standard Pyromet-
size. The static atmosphere prevailing permits the cones being mounted to
ric Cones on plaques of refractory material that have a
face outward, if so desired.
composition that will not affect the fusibility of the cones (see
6.4 Heating:
Note 4). Mount both test and PCE cones with the base
6.4.1 Perform the heating in a suitable furnace, operating
embedded so that the length of the sloping face of the cone
with an oxidizing atmosphere, at rates to conform to the
above the plaque shall be ⁄16 in. (24 mm) and the face of the
followingrequirements(seeNote6andNote7).Itisadvisable,
cone (about which bending takes place) shall be inclined at an
but not mandatory that the furnace temperature be controlled
angle of 82° with the horizontal. Arrange the test cones with
with a calibrated thermocouple or radiation pyrometer con-
respect to the PCE cones as shown in Fig. 3,
...
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