ASTM D7626-19e1

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.
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Designation: D7626 − 19
Standard Test Methods for
Determining the Organic Treat Loading of Organophilic
Clay
This standard is issued under the fixed designation D7626; 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.
ε NOTE—Corrected data sheet editorially in Appendix X1 in February 2020.
1. Scope priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1.1 This standard covers two index test methods that can be
1.5 This international standard was developed in accor-
used in the evaluation of the amount of organic compound
dance with internationally recognized principles on standard-
chemically bonded to the base clay portion of a representative
ization established in the Decision on Principles for the
sample of organophilic clay.
Development of International Standards, Guides and Recom-
1.2 The values stated in SI units are to be regarded as the
mendations issued by the World Trade Organization Technical
standard. No other units of measurement are included in this
Barriers to Trade (TBT) Committee.
standard. Reporting of test results in units other than SI shall
not be regarded as nonconformance with this standard.
2. Referenced Documents
NOTE 1—This standard is presented using SI units. Use of units other
2.1 ASTM Standards:
than SI is allowed. However, if other units are used, the performance of a
D653 Terminology Relating to Soil, Rock, and Contained
units conversion check of the calculations should be included as a part of
Fluids
the calculations.
D3740 Practice for Minimum Requirements for Agencies
1.3 All observed and calculated values shall conform to the
Engaged in Testing and/or Inspection of Soil and Rock as
guidelines for significant digits and rounding established in
Used in Engineering Design and Construction
Practice D6026.
D4753 Guide for Evaluating, Selecting, and Specifying Bal-
1.3.1 Two test methods are provided in this standard. The
ances and Standard Masses for Use in Soil, Rock, and
methods differ in equipment, the size of the specimen (mass)
Construction Materials Testing
required and the significant digits reported.
D6026 Practice for Using Significant Digits in Geotechnical
1.3.2 Theproceduresusedtospecifyhowdataarecollected/
Data
recorded or calculated in this standard are regarded as the
E11 Specification for Woven Wire Test Sieve Cloth and Test
industry standard. In addition, they are representative of the
Sieves
significant digits that generally should be retained. The proce-
E145 Specification for Gravity-Convection and Forced-
dures used do not consider material variation, purpose for
Ventilation Ovens
obtaining the data, special purpose studies, or any consider-
ations for the user’s objectives; and it is common practice to
3. Terminology
increase or reduce significant digits of the reported data to be
3.1 Definitions—For definitions of common technical terms
commensuratewiththeseconsiderations.Itisbeyondthescope
of this standard to consider significant digits used in analysis in this standard, refer to Terminology D653.
methods for engineering design.
3.2 Definitions of Terms Specific to This Standard:
1.4 This standard does not purport to address all of the
3.2.1 base clay, n—an untreated naturally occurring clay
safety concerns, if any, associated with its use. It is the (for example, bentonite, kaolinite).
responsibility of the user of this standard to establish appro-
3.2.2 initial mass loss, n—the amount of water and residual
organic compound not bound to the base clay.
These test methods are under the jurisdiction ofASTM Committee D18 on Soil
andRockandarethedirectresponsibilityofSubcommitteeD18.21onGroundwater
and Vadose Zone Investigations. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Feb. 1, 2019. Published February 2019. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2010. Last previous edition approved in 2018 as D7626–10(2018). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D7626-19E01. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D7626 − 19
3.2.3 organic treat loading, n—the amount of organic com- 6.2 Muffle Furnace, capable of producing constant tempera-
pound chemically bonded to the base clay portion of an ture of 750 °C.
organophilic clay.
6.3 TGA, thermal gravimetric analyzer capable of reaching
3.2.4 organophilic, adj—having a strong affinity for oil and
a minimum 750 °C with a balance having 0.001 mg readability
other insoluble organic compounds.
and any ancillary equipment, such as instrumental air, as
recommended by the TGA manufacturer.
3.2.5 organophilic clay, n—a manufactured material con-
sisting of base clay to which an organic compound has been
6.4 Balance or Scale, a balance or scale for determining the
chemically bonded to the clay surface.
mass of organophilic clay having a minimum capacity of 100
g and meeting the requirements of Guide D4753 for a balance
4. Summary of Test Methods
or scale of 0.01 g readability.
4.1 Test Method A—Initial mass loss is determined by
6.5 Porcelain Container and Cover.
drying an organophilic clay specimen at 160 °C in an oven or
6.6 Desiccator.
muffle furnace. The initial mass loss is expressed as a percent-
age of the as-received mass. The ash content of the organo-
6.7 Mortar and Pestle.
philic clay specimen is determined by igniting the dried
6.8 Sieve, 0.075 mm sieve opening, meeting the require-
specimen from the initial mass loss determination in a muffle
ments of Specification E11.
furnace at 750 °C.
6.9 Pan, slightly larger than sieve.
4.2 Test Method B—An organophilic clay specimen is
heated at a controlled rate in a thermal gravimetric analyzer.
6.10 Gloves, Tongs or Other Suitable Equipment or Com-
Percent initial mass loss and ash are taken from thermal
binations Thereof, to safely handle porcelain containers to and
gravimetric analyzer report.
from furnace.
4.3 Some volatile structural matter within the base clay will
7. Sample and Specimen
be lost during the last stage of heating. Organic treat loading is
determinedonadryweightbasisbyacalculationthataccounts
7.1 Collect a representative sample of organophilic clay.
for the initial mass loss, ash, and a nominal percent of volatile
This test method does not address, in any detail, procurement
structural matter within the base clay.
of the sample. It is assumed the sample is obtained using
NOTE 2—The supplier of the organophilic clay must be able to verify
appropriate methods and is representative of the material under
with historical data the nominal percent mass of the base clay (on a dry
evaluation. From the sample obtained from manufacturer,
weight basis) remainingaftersimilarheating.Thisvalueistypically in the
range of 94 to 96 %. obtain a 50 g sub-sample.
7.2 Specimen—Obtain a representative portion from the
5. Significance and Use
sub-sampletoprovidesufficientmaterialpassingthe0.075mm
5.1 This standard test method is intended as an index test to
sieve.
determine the organic treat loading of organophilic clay. This
7.2.1 Crushorganophilicclaysamplewithmortarandpestle
standard test method can be used for manufacturing quality
and then screen through 0.075 mm sieve. Retain finer fraction
control and construction quality assurance material evaluation.
of sub-sample from which the test specimen is to be obtained.
Unless otherwise requested, only one specimen is used in the
5.2 The percent organic treat loading of organophilic clay is
test procedure.
arelativeindicatorofitsadsorptivecapacity.Organophilicclay
is used for remediation of contaminated sediment, soil, and
8. Procedures
groundwater.
5.3 The two test methods denote different devices, a muffle
8.1 Test Method A—Oven or Muffle Furnace or Combina-
furnace and a thermal gravimetric analyzer. The thermal tions Thereof:
gravimetric analyzer may be programmed to reach a higher
8.1.1 Initial Mass Loss Determination:
temperaturethanthemufflefurnace,buttheorganicmatterwill
8.1.1.1 Record to the nearest 0.01 g the mass of a clean, dry
be burnt off at 750 °C.
porcelain container and cover.
NOTE 3—The quality of the result produced by this standard is
8.1.1.2 Place a test specimen of at least 10 g and no more
dependent on the competence of the personnel performing it, and the
than 50 g in the porcelain container and record mass to the
suitability of the equipment and facilities used. Agencies that meet the
nearest 0.01 g.
criteria of Practice D3740 are generally considered capable of competent
and objective testing/sampling/inspection/etc. Users of this standard are
8.1.1.3 Dry uncovered in an oven or muffle furnace for at
cautioned that compliance with Practice D3740 does not in itself assure
least 16 h at 160 °C or until there is no change in mass of the
reliable results. Reliable results depend on many factors; Practice D3740
specimen after further drying in periods in excess of 1 h.
provides a means of evaluating some of those factors.
8.1.1.4 Remove from the oven, cover tightly, cool in a
desiccator and record the mass (m ) to the nearest 0.01 g.
6. Apparatus
dry
8.1.1.5 Calculate the init
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