ASTM C837-99(2003)
(Test Method)Standard Test Method for Methylene Blue Index of Clay
Standard Test Method for Methylene Blue Index of Clay
SIGNIFICANCE AND USE
Tests run on many clays generally indicate that a straight-line relationship exists between the methylene blue index (MBI) and such fundamental clay properties as cation exchange capacity, dry bond strength, and casting rate. Where the colloidal portion of the clay is kaolinite, there is also a direct correlation with specific surface (as determined by nitrogen adsorption). Where the colloidal portion contains significant amounts of illite or montmorillonite, the same close correlation does not exist. The MBI better correlates with the ceramic-forming properties than does the specific surface.
That portion of a clay lying within the colloidal range (generally defined as the 0.5- to 0.001-μm range), determines the strictly colloidal properties of the clay and, together with the amount and type of organic material associated with the clay and the 2- to 0.2-μm fraction, largely determines the properties of the clay when used in ceramic-forming processes. While the specific surface of a clay is a function of the particle size and morphology and a relationship exists between dye adsorption and specific surface, the MBI should not be considered to be a particle size analysis since the value obtained is dominated by the character of only the very fine end of the particle size distribution. This procedure describes the determination of the dye adsorption (in this case, methylene blue) of a clay.
SCOPE
1.1 This test method covers the measurement of the adsorption of methylene blue dye by a clay, which is calculated as a methylene blue index for a clay.
1.2 This standard does not purport to address all of the safety problems, 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
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:C837–99 (Reapproved 2003)
Standard Test Method for
Methylene Blue Index of Clay
This standard is issued under the fixed designation C 837; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope particle size distribution. This procedure describes the deter-
minationofthedyeadsorption(inthiscase,methyleneblue)of
1.1 This test method covers the measurement of the adsorp-
a clay.
tion of methylene blue dye by a clay, which is calculated as a
methylene blue index for a clay.
4. Apparatus
1.2 This standard does not purport to address all of the
4.1 Balance, accurate to 0.01 g.
safety concerns, if any, associated with its use. It is the
4.2 Mixer.
responsibility of the user of this standard to establish appro-
4.3 pH Meter or pH Paper.
priate safety and health practices and determine the applica-
4.4 Beaker, 600 mL.
bility of regulatory limitations prior to use.
4.5 Buret,25mL.
2. Referenced Documents 4.6 Medicine Dropper or Glass Stirring Rod.
4.7 Filter Paper, Baroid No. 987.
2.1 ASTM Standards:
C 324 Test Method for Free Moisture in Ceramic Whitew-
5. Reagents
are Clays
5.1 Purity of Reagents—Reagent grade chemicals shall be
3. Significance and Use used in all tests. Unless otherwise indicated, it is intended that
all reagents shall conform to the specifications of the Commit-
3.1 Tests run on many clays generally indicate that a
tee onAnalytical Reagents of theAmerican Chemical Society,
straight-line relationship exists between the methylene blue
where such specifications are available. Other grades may be
index (MBI) and such fundamental clay properties as cation
used, provided it is first ascertained that the reagent is of
exchange capacity, dry bond strength, and casting rate. Where
sufficiently high purity to permit its use without lessening the
the colloidal portion of the clay is kaolinite, there is also a
accuracy of the determination.
direct correlation with specific surface (as determined by
5.2 Purity of Water—Unless otherwise indicated, references
nitrogen adsorption). Where the colloidal portion contains
to water shall be understood to mean distilled water or water of
significant amounts of illite or montmorillonite, the same close
equal purity.
correlation does not exist. The MBI better correlates with the
5.3 Methylene Blue Solution (1 mL = 0.01 meq) —Store in
ceramic-forming properties than does the specific surface.
darkness.
3.2 That portion of a clay lying within the colloidal range
5.4 Sulfuric Acid (0.1N).
(generally defined as the 0.5- to 0.001-µm range), determines
the strictly colloidal properties of the clay and, together with
6. Procedure
the amount and type of organic material associated with the
6.1 Weigh out 2.00 g of clay that has been dried in
clay and the 2- to 0.2-µm fraction, largely determines the
accordance with the procedure inTest Method C 324 and place
properties of the clay when used in ceramic-forming processes.
While the specific surface of a clay is a function of the particle
size and morphology and a relationship exists between dye
This test method is based on the use of the Model F Lightnin mixer, which is
available from Mixing Equipment Co., Inc., Rochester, NY. However, it has been
adsorption and specific surface, the MBI should not be con-
found that some clays are not completely dispersed in this apparatus, and so results
sidered to be a particle size analysis since the value obtained is
may be spurious. It has been found that the Waring Blender, available from Waring
dominated by the character of only the very fine end of the
Products Division, Dynamics Corporation ofAmerica, New Hartford, CT 06057, is
successful in dispersing all clays.
Available from Baroid Div., National Lead Co., No. 425-15.
1 5
This test method is under the jurisdiction of ASTM Committee C-21 on Reagent Chemicals, American Chemical Society Specifications, American
Ceramic Whitewares and Related Products and is the direct responsibility of Chemical Society, Washington, DC. For suggestions on
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.