ASTM C323-56(2016)
(Test Method)Standard Test Methods for Chemical Analysis of Ceramic Whiteware Clays (Withdrawn 2024)
Standard Test Methods for Chemical Analysis of Ceramic Whiteware Clays (Withdrawn 2024)
ABSTRACT
These test methods cover the chemical analysis of clays used in the manufacture of ceramic whitewares. Determine moisture on the sample in its ordinary air-dried condition. Determine all other percentage compositions on moisture-free samples and report accordingly on a moisture-free basis. Make blank determinations on the reagents for each constituent in the whiteware clay and deduct this blank in each case. The sample shall be heated to a constant weight at a given temperature; the loss in weight is recorded as moisture. For the determination of the silica blank, approximately 0.25 g of alumina should be added as aluminium chloride. The procedure for the determination of iron, aluminium, and titanium oxide blank are presented in details. The procedure for the determination of iron oxide, titania, alumina, lime, magnesia, and alkalies blank are discussed and presented in details.
SCOPE
1.1 These test methods cover the chemical analysis of clays used in the manufacture of ceramic whitewares.
1.2 The analytical procedures appear in the following order:
Section
Moisture
7
Loss on Ignition
8
Silica
9
Iron, Aluminum, and Titanium Oxides
10
Iron Oxide
11
Titania
12
Alumina
13
Lime
14
Magnesia
15
Alkalies
16
Note 1: These test methods have been compiled as standard procedures for use in referee analyses. These test methods, however, when the determination of iron oxide as Fe2O3 is involved, are not intended to preclude the use of other procedures that give results within the permissible variations. For the sake of uniformity the classical Zimmerman-Reinhardt procedure is specified for the determination of iron oxide. It is recognized that numerous other procedures are equally accurate and often more convenient. The other procedures commonly in use include reduction of an oxidized solution with zinc or other metal, and titration with standard potassium permanganate (KMnO4) or potassium dichromate (K2Cr2O7) solution, as well as titration with a standard solution of titanous chloride in an oxidized solution. These procedures shall be considered acceptable, provided the analyst has obtained results by his special procedure that check with the Zimmerman-Reinhardt procedure within the limits specified in Section 17. It is suggested that National Institute of Standards and Technology standard samples be used for checking the accuracy of procedures.
It will be understood that the making of a complete analysis of a ceramic whiteware clay is a difficult procedure requiring a wide knowledge of the chemistry involved in the operations and a thorough training in carrying out the work. A skilled analyst of good training is therefore required to do the work. The descriptions here given cover the vital points of procedure, but frequent reference in regard to the details of the various manipulations should be made to “Applied Inorganic Analysis” by Hillebrand and Lundell2 and to similar publications. Particularly in the determination of alumina, reference should be made to Scientific Paper No. 286 of the National Bureau of Standards.3
1.3 The values stated in acceptable metric units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 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.
WITHDRAWN RATIONALE
These test methods covered the chemical analysis of clays used in the manufacture of ceramic whitewares.
Formerly under the jurisdiction of Committee C21 on Ceramic Whitewares and Related Products, these test methods were withdrawn in February 2024. This standard is being withdrawn without replacement due to its limited use by industry.
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Standards Content (Sample)
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: C323 − 56 (Reapproved 2016)
Standard Test Methods for
Chemical Analysis of Ceramic Whiteware Clays
This standard is issued under the fixed designation C323; 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.
No. 286 of the National Bureau of Standards.
1. Scope
1.3 The values stated in acceptable metric units are to be
1.1 These test methods cover the chemical analysis of clays
regarded as the standard. The values given in parentheses are
used in the manufacture of ceramic whitewares.
for information only.
1.2 The analytical procedures appear in the following order:
1.4 This standard does not purport to address all of the
Section
safety concerns, if any, associated with its use. It is the
Moisture 7
Loss on Ignition 8 responsibility of the user of this standard to establish appro-
Silica 9
priate safety and health practices and determine the applica-
Iron, Aluminum, and Titanium Oxides 10
bility of regulatory limitations prior to use.
Iron Oxide 11
Titania 12
Alumina 13
2. Referenced Documents
Lime 14
Magnesia 15 2.1 ASTM Standards:
Alkalies 16
C322 Practice for Sampling Ceramic Whiteware Clays
E11 Specification for Woven Wire Test Sieve Cloth and Test
NOTE 1—These test methods have been compiled as standard proce-
dures for use in referee analyses. These test methods, however, when the Sieves
determination of iron oxide as Fe O is involved, are not intended to
2 3
preclude the use of other procedures that give results within the permis-
3. Reagents
sible variations. For the sake of uniformity the classical Zimmerman-
3.1 Unless otherwise indicated, it is intended that all re-
Reinhardt procedure is specified for the determination of iron oxide. It is
recognized that numerous other procedures are equally accurate and often
agents shall conform to the specifications of the Committee on
more convenient. The other procedures commonly in use include reduc-
Analytical Reagents of theAmerican Chemical Society, where
tion of an oxidized solution with zinc or other metal, and titration with
such specifications are available. Other grades may be used,
standard potassium permanganate (KMnO ) or potassium dichromate
provided it is first ascertained that the reagent is of sufficiently
(K Cr O )solution,aswellastitrationwithastandardsolutionoftitanous
2 2 7
high purity to permit its use without lessening the accuracy of
chloride in an oxidized solution. These procedures shall be considered
acceptable, provided the analyst has obtained results by his special
the determination. Unless otherwise indicated, references to
procedurethatcheckwiththeZimmerman-Reinhardtprocedurewithinthe
water shall be understood to mean distilled water. Paragraphs
limits specified in Section 17. It is suggested that National Institute of
3.1.1 – 3.1.16 include those reagents common to two or more
Standards and Technology standard samples be used for checking the
oftheanalyticalprocedures.Otherreagentswillbefoundlisted
accuracy of procedures.
It will be understood that the making of a complete analysis of a with the particular test method in which they are prescribed.
ceramic whiteware clay is a difficult procedure requiring a wide knowl-
3.1.1 Concentrated Acids and Ammonium Hydroxide—
edge of the chemistry involved in the operations and a thorough training
Concentrated acids and ammonium hydroxide of approxi-
in carrying out the work. A skilled analyst of good training is therefore
mately the following specific gravities or concentrations will
required to do the work.The descriptions here given cover the vital points
be required:
of procedure, but frequent reference in regard to the details of the various
manipulations should be made to “Applied Inorganic Analysis” by
Hillebrand and Lundell and to similar publications. Particularly in the
determination of alumina, reference should be made to Scientific Paper
Blum, W., “Determination of Alumina as Oxide,” National Bureau of
Standards, Scientific Paper No. 286.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
These test methods are under the jurisdiction of ASTM Committee C21 on Standards volume information, refer to the standard’s Document Summary page on
Ceramic Whitewares and Related Products and are the direct responsibility of the ASTM website.
Subcommittee C21.04 on Raw Materials. Reagent Chemicals, American Chemical Society Specifications, American
Current edition approved July 1, 2016. Published July 2016. Originally approved Chemical Society, Washington, DC. For suggestions on the testing of reagents not
in 1956. Last previous edition approved in 2011 as C323 – 56 (2011). DOI: listed by the American Chemical Society, see Analar Standards for Laboratory
10.1520/C0323-56R16. Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Hillebrand,W. F., and Lundell, G. E. F., Applied Inorganic Analysis,Wiley and and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
Son, New York, 1929. MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C323 − 56 (2016)
L.Allow to stand for one week, filter through an asbestos mat,
Hydrochloric acid (HCl) 1.19 sp gr
Nitric acid (HNO ) 1.42spgr
porous glass, or porcelain filter, and keep in a dark place.
Sulfuric acid (H SO ) 1.84spgr
2 4
Standardize against the National Institute of Standards and
Hydrofluoric acid (HF) 40 %
A
Technology standard Sample No. 40c of sodium oxalate.
Perchloric acid (HClO ) 60to70%,cp
B
Sulfurous acid (H SO ) 6 % solution
2 3 3.1.14 Sodium Arsenite, Standard Solution— Dissolve
Ammonium hydroxide (NH OH) 0.90 sp gr
0.908 g of arsenious oxide, (As O ), in a small amount of hot
2 3
___________
sodium carbonate (Na CO ) solution, cool, filter, and dilute to
2 3
A
Lower purity varieties may contain aluminum oxide, (Al O ), as an impurity. 1 L. Standardize against a steel of known manganese content.
2 3
B
As supplied by reagent manufacturers.
3.1.15 Stannous Chloride Solution (50 g/L)—Dissolve 50 g
of SnCl in 100 mLof HCl and dilute to 1000 mL. Keep a few
3.1.2 DilutedAcidsandAmmoniumHydroxide—Thediluted
pieces of metallic tin in the bottle.
acids and ammonium hydroxide referred to are of varying
3.1.16 Titania, Standard Solution—Weigh out 0.05 g of
percentages by volume. They shall be made up by mixing
calcined titanium dioxide (TiO ). Fuse with 10 g of K S O in
2 2 2 7
proportional volumes of the concentrated reagent and water.
a clean platinum crucible, keeping the temperature as low as
The diluted sulfuric acid mixtures shall be made up by slowly
possible to maintain fluidity. Cool, and dissolve in about 300
stirring the acid into the water. These diluted acids and
mL of H SO (1 + 5). Cool, transfer to a 500-mL volumetric
2 4
ammoniumhydroxidearedesignatedinthemethodsas(1 + 4),
flask, dilute to the mark with water, and mix thoroughly. To
(1 + 9), and so forth, except very diluted solutions which are
standardize the solution, take two 50-mL portions in 400-mL
referred to by the percent of reagent added. The designation in
beakers, dilute, boil, and precipitate with NH OH. Filter, and
parentheses indicates the ratio of the volume of the concen-
wash with hot water. Place the papers in the original beakers,
trated reagent to the volume of water; for example, H SO
2 4
add 15 mL of HCl, stir to macerate the paper, dilute, and
(1 + 9) contains 10 volume % of H SO (sp gr 1.84). The
2 4
precipitate again with NH OH. Filter, and wash with hot water
following will be required:
untilfreeofalkalisalts.Ignitecarefully,blast,andweigh.From
Volume %
the weight determined, calculate the strength of the solution.
HCl 50
H SO 50 4. Sampling
2 4
4.1 Selection of Sample—Obtain the sample in accordance
HNO 30
3 with Practice C322.
NH OH 50 4.2 Crushthesampleinasmalljaworroll-typecrusherwith
hardenedtool-steelfacestopassa2.36-mm(No.8)sieve(Note
3.1.3 Ammonium Chloride (2 %) —Dissolve2gofNH Cl
2). Crush the sample to pass a 850-µm (No. 20) sieve, mix, and
in 100 mL of water. quarter to about 50 g. Grind this 50-g sample so that it will all
3.1.4 Ammonium Oxalate Solution (Saturated)—Dissolve 4 pass a 150-µm (No. 100) sieve, unless otherwise specified, mix
gof(NH ) C O in 100 mL of water. thoroughly, and place in a container that will ensure freedom
4 2 2
3.1.5 Chloroplatinic Acid Solution (10 %). from contamination. Do fine grinding in a suitable mortar
(agate, mullite, alumina, or boron carbide) to prevent the
3.1.6 Diammonium Phosphate Solution—Dissolve 10 g of
introduction of impurities. Take precautions to prevent con-
(NH ) HPO in 100 mL of water.
4 2 4
tamination of the sample by steel particles from the sampling
3.1.7 Ethyl Alcohol (80 %) —Prepare a solution containing
equipment during crushing or grinding.
80 volume % of ethyl alcohol in water.
3.1.8 Ethyl Alcohol (Absolute)—Certain commercial brands
NOTE 2—Detailed requirements for these sieves are given in Specifi-
of denatured absolute alcohol are satisfactory as well as being
cation E11.
considerably less expensive than the reagent grade absolute
5. Method of Analysis
alcohol.
3.1.9 Hydrogen Peroxide (30 %) (H O ).
5.1 Determine moisture on the sample in its ordinary
2 2
3.1.10 Manganese Sulfate Solution—Dissolve 70 g of crys-
air-dried condition. Determine all other percentage composi-
talline MnSO in 500 mLof water.Add 140 mLof phosphoric tions on moisture-free samples and report accordingly on a
acid (H PO , sp gr 1.7), and 130 mL of sulfuric acid (H SO ,
moisture-free basis. The drying temperature recommended for
3 4 2 4
sp gr 1.84). Dilute to 1 L. all moisture determinations is 105 to 110°C. Whenever a
sample is weighed out for any determination other than
3.1.11 Mercuric Chloride Solution (Saturated)—Prepare a
saturated solution of HgCl . moisture,itshallbemoisture-free.Ifpreferred,thesamplemay
be dried in a weighing bottle from which the required samples
3.1.12 Potassium Permanganate, Standard Solution
shall be weighed out.
(0.1N)—Dissolve 3.25 g of KMnO in 1000 mL of water.
Allow to stand for one week, filter through an asbestos mat,
6. Blank Determinations
porous glass, or porcelain filter, and keep in a dark place.
Standardize against the National Institute of Standards and
6.1 Make blank determinations on the reagents for each
Technology standard Sample No. 40c of sodium oxalate. constituent in the whiteware clay and deduct this blank in each
3.1.13 Potassium Permanganate, Standard Solution case. For the determination of the silica (SiO ) blank, approxi-
(0.04N)—Dissolve 2.5 g of KMnO in water and make up to 2 mately 0.25 g ofAl O should be added as aluminum chloride.
4 2 3
C323 − 56 (2016)
7. Moisture of 0.1 % methyl red solution. Heat the solution almost to
boiling, and add slowly NH OH (1 + 1) until the indicator has
7.1 Weigh 1.00 g of the sample and heat to constant weight
changed to a yellow color. Boil for several minutes to remove
at a temperature not under 105 nor over 110°C. Record the loss
the excess ammonia. Allow to settle for 30 min and decant
in weight as moisture.
through an open, rapid-filtering acid-washed filter paper, trans-
ferring the precipitate to the paper and washing the beaker and
8. Loss on Ignition
paper several times with a warm 2 % NH Cl solution. Reserve
8.1 Weigh 1.000 g of the moisture-free (105 to 110°C)
the filtrate, “A,” for the determination of calcium oxide (CaO)
sample and heat to constant weight over a blast lamp, or in an
and magnesium oxide (MgO) (Section 14). Return the precipi-
electric muffle furnace, at 900 to 1000°C. Record the loss in
tate and paper to the original beaker, add 50 mL of hot water
weight as the ignition loss.
and 10 mL of HCl (sp gr 1.19). Stir until the precipitate is
dissolved and the paper is well macerated. Dilute to about 200
9. Silica
mL with hot water, precipitate and filter as before. Combine
9.1 Weigh 0.5000 g of the moisture-free (105 to 110°C)
this filtrate “B” with filtrate “A.” Wash the paper and precipi-
sample into a platinum crucible containing about5gof
tate with a warm 2 % NH Cl solution. Place the precipitate in
powdered anhydrous Na CO and mix well with a platinum
2 3
a weighed platinum crucible and ignite. Continue the ignition
wire. Cover the mixture with a little more Na CO . Heat
2 3
at 1200°C to constant weight (15 to 20 min is usually
gradually to the full heat of a good burner (1000 to 1100°C)
sufficient). Cool in a desiccator, and weigh with the crucible
maintained for about 1 h until complete solution is obtained.
covered with the lid.The R O consists of the aluminum oxide
2 3
Place the crucible cover on a triangle, and when the melt has
(Al O ), TiO , and Fe O present in the sample. In addition,
2 3 2 2 3
partially cooled, pour it on the lid (Note 3). When cool, place
there may be small amounts of phosphoric anhydride (P O ),
2 5
the crucible and lid in a 150-mL beaker, placing the button on
zirconium oxide (ZrO ), vanadium pentoxide (V O ), and
2 2 5
a watch glass above the beaker. Add 30 mL of HCl (1 + 1).
chromic oxide (Cr O ).
2 3
When solution is complete wash off the crucible and lid with
HCl (1 + 4), taking care to remove all SiO . Place the button in
11. Iron Oxide
the solution. Transfer the contents of the beaker to an evapo-
11.1 Procedure A: Fe O Determined on R O Sample—
rating dish and evaporate to dryness on a steam bath. Bake for
2 3 2 3
Heat the R O precipitate (Note 4) obtained in the determina-
1hat110°C.Add20to30mLofHCl(1 + 1)and50mLofhot
2 3
tion of iron, aluminum, and titanium oxides (Section 10), with
water. When all salts have been dissolved, allow to settle for
fused K S O or Na S O until solution is complete. Dissolve
several minutes and then filter through a general-purpose grade
2 2 7 2 2 7
the fusion in 50 mL of H SO (1 + 9) and evaporate to fumes.
acid-washed medium-retention filter paper. Wash the SiO
2 4
Cool, dilute with water, and filter off the SiO , washing with
three times by decantation using 20- to 30-mL portions of first
hot water. Reserve the filtrate for the determination of Fe O
hot water, then HCl (1 + 1), then hot water again. Transfer the 2 3
and TiO . Ignite the SiO in a platinum crucible and weigh.
precipitate to the
...
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: C323 − 56 (Reapproved 2016)
Standard Test Methods for
Chemical Analysis of Ceramic Whiteware Clays
This standard is issued under the fixed designation C323; 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.
No. 286 of the National Bureau of Standards.
1. Scope
1.3 The values stated in acceptable metric units are to be
1.1 These test methods cover the chemical analysis of clays
regarded as the standard. The values given in parentheses are
used in the manufacture of ceramic whitewares.
for information only.
1.2 The analytical procedures appear in the following order:
1.4 This standard does not purport to address all of the
Section
safety concerns, if any, associated with its use. It is the
Moisture 7
responsibility of the user of this standard to establish appro-
Loss on Ignition 8
Silica 9
priate safety and health practices and determine the applica-
Iron, Aluminum, and Titanium Oxides 10
bility of regulatory limitations prior to use.
Iron Oxide 11
Titania 12
Alumina 13
2. Referenced Documents
Lime 14
2.1 ASTM Standards:
Magnesia 15
Alkalies 16
C322 Practice for Sampling Ceramic Whiteware Clays
E11 Specification for Woven Wire Test Sieve Cloth and Test
NOTE 1—These test methods have been compiled as standard proce-
dures for use in referee analyses. These test methods, however, when the
Sieves
determination of iron oxide as Fe O is involved, are not intended to
2 3
preclude the use of other procedures that give results within the permis-
3. Reagents
sible variations. For the sake of uniformity the classical Zimmerman-
3.1 Unless otherwise indicated, it is intended that all re-
Reinhardt procedure is specified for the determination of iron oxide. It is
recognized that numerous other procedures are equally accurate and often
agents shall conform to the specifications of the Committee on
more convenient. The other procedures commonly in use include reduc-
Analytical Reagents of the American Chemical Society, where
tion of an oxidized solution with zinc or other metal, and titration with
such specifications are available. Other grades may be used,
standard potassium permanganate (KMnO ) or potassium dichromate
provided it is first ascertained that the reagent is of sufficiently
(K Cr O ) solution, as well as titration with a standard solution of titanous
2 2 7
chloride in an oxidized solution. These procedures shall be considered high purity to permit its use without lessening the accuracy of
acceptable, provided the analyst has obtained results by his special
the determination. Unless otherwise indicated, references to
procedure that check with the Zimmerman-Reinhardt procedure within the
water shall be understood to mean distilled water. Paragraphs
limits specified in Section 17. It is suggested that National Institute of
3.1.1 – 3.1.16 include those reagents common to two or more
Standards and Technology standard samples be used for checking the
of the analytical procedures. Other reagents will be found listed
accuracy of procedures.
It will be understood that the making of a complete analysis of a with the particular test method in which they are prescribed.
ceramic whiteware clay is a difficult procedure requiring a wide knowl-
3.1.1 Concentrated Acids and Ammonium Hydroxide—
edge of the chemistry involved in the operations and a thorough training
Concentrated acids and ammonium hydroxide of approxi-
in carrying out the work. A skilled analyst of good training is therefore
mately the following specific gravities or concentrations will
required to do the work. The descriptions here given cover the vital points
be required:
of procedure, but frequent reference in regard to the details of the various
manipulations should be made to “Applied Inorganic Analysis” by
Hillebrand and Lundell and to similar publications. Particularly in the
determination of alumina, reference should be made to Scientific Paper 3
Blum, W., “Determination of Alumina as Oxide,” National Bureau of
Standards, Scientific Paper No. 286.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
These test methods are under the jurisdiction of ASTM Committee C21 on Standards volume information, refer to the standard’s Document Summary page on
Ceramic Whitewares and Related Products and are the direct responsibility of the ASTM website.
Subcommittee C21.04 on Raw Materials. Reagent Chemicals, American Chemical Society Specifications, American
Current edition approved July 1, 2016. Published July 2016. Originally approved Chemical Society, Washington, DC. For suggestions on the testing of reagents not
in 1956. Last previous edition approved in 2011 as C323 – 56 (2011). DOI: listed by the American Chemical Society, see Analar Standards for Laboratory
10.1520/C0323-56R16. Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Hillebrand, W. F., and Lundell, G. E. F., Applied Inorganic Analysis, Wiley and and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
Son, New York, 1929. MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C323 − 56 (2016)
L. Allow to stand for one week, filter through an asbestos mat,
Hydrochloric acid (HCl) 1.19 sp gr
Nitric acid (HNO ) 1.42 sp gr
3 porous glass, or porcelain filter, and keep in a dark place.
Sulfuric acid (H SO ) 1.84 sp gr
2 4
Standardize against the National Institute of Standards and
Hydrofluoric acid (HF) 40 %
A
Technology standard Sample No. 40c of sodium oxalate.
Perchloric acid (HClO ) 60 to 70 %, cp
B
Sulfurous acid (H SO ) 6 % solution
2 3
3.1.14 Sodium Arsenite, Standard Solution— Dissolve
Ammonium hydroxide (NH OH) 0.90 sp gr
0.908 g of arsenious oxide, (As O ), in a small amount of hot
2 3
___________
sodium carbonate (Na CO ) solution, cool, filter, and dilute to
2 3
A
1 L. Standardize against a steel of known manganese content.
Lower purity varieties may contain aluminum oxide, (Al O ), as an impurity.
2 3
B
As supplied by reagent manufacturers.
3.1.15 Stannous Chloride Solution (50 g/L)—Dissolve 50 g
of SnCl in 100 mL of HCl and dilute to 1000 mL. Keep a few
3.1.2 Diluted Acids and Ammonium Hydroxide—The diluted
pieces of metallic tin in the bottle.
acids and ammonium hydroxide referred to are of varying
3.1.16 Titania, Standard Solution—Weigh out 0.05 g of
percentages by volume. They shall be made up by mixing
calcined titanium dioxide (TiO ). Fuse with 10 g of K S O in
2 2 2 7
proportional volumes of the concentrated reagent and water.
a clean platinum crucible, keeping the temperature as low as
The diluted sulfuric acid mixtures shall be made up by slowly
possible to maintain fluidity. Cool, and dissolve in about 300
stirring the acid into the water. These diluted acids and
mL of H SO (1 + 5). Cool, transfer to a 500-mL volumetric
2 4
ammonium hydroxide are designated in the methods as (1 + 4),
flask, dilute to the mark with water, and mix thoroughly. To
(1 + 9), and so forth, except very diluted solutions which are
standardize the solution, take two 50-mL portions in 400-mL
referred to by the percent of reagent added. The designation in
beakers, dilute, boil, and precipitate with NH OH. Filter, and
parentheses indicates the ratio of the volume of the concen-
wash with hot water. Place the papers in the original beakers,
trated reagent to the volume of water; for example, H SO
2 4
add 15 mL of HCl, stir to macerate the paper, dilute, and
(1 + 9) contains 10 volume % of H SO (sp gr 1.84). The
2 4
precipitate again with NH OH. Filter, and wash with hot water
following will be required:
until free of alkali salts. Ignite carefully, blast, and weigh. From
Volume %
the weight determined, calculate the strength of the solution.
HCl 50
H SO 50
4. Sampling
2 4
4.1 Selection of Sample—Obtain the sample in accordance
HNO 30
with Practice C322.
NH OH 50 4.2 Crush the sample in a small jaw or roll-type crusher with
hardened tool-steel faces to pass a 2.36-mm (No. 8) sieve (Note
3.1.3 Ammonium Chloride (2 %) —Dissolve 2 g of NH Cl 2). Crush the sample to pass a 850-µm (No. 20) sieve, mix, and
in 100 mL of water.
quarter to about 50 g. Grind this 50-g sample so that it will all
3.1.4 Ammonium Oxalate Solution (Saturated)—Dissolve 4 pass a 150-µm (No. 100) sieve, unless otherwise specified, mix
g of (NH ) C O in 100 mL of water. thoroughly, and place in a container that will ensure freedom
4 2 2
from contamination. Do fine grinding in a suitable mortar
3.1.5 Chloroplatinic Acid Solution (10 %).
(agate, mullite, alumina, or boron carbide) to prevent the
3.1.6 Diammonium Phosphate Solution—Dissolve 10 g of
introduction of impurities. Take precautions to prevent con-
(NH ) HPO in 100 mL of water.
4 2 4
tamination of the sample by steel particles from the sampling
3.1.7 Ethyl Alcohol (80 %) —Prepare a solution containing
equipment during crushing or grinding.
80 volume % of ethyl alcohol in water.
3.1.8 Ethyl Alcohol (Absolute)—Certain commercial brands
NOTE 2—Detailed requirements for these sieves are given in Specifi-
of denatured absolute alcohol are satisfactory as well as being
cation E11.
considerably less expensive than the reagent grade absolute
5. Method of Analysis
alcohol.
3.1.9 Hydrogen Peroxide (30 %) (H O ).
5.1 Determine moisture on the sample in its ordinary
2 2
3.1.10 Manganese Sulfate Solution—Dissolve 70 g of crys- air-dried condition. Determine all other percentage composi-
talline MnSO in 500 mL of water. Add 140 mL of phosphoric
tions on moisture-free samples and report accordingly on a
acid (H PO , sp gr 1.7), and 130 mL of sulfuric acid (H SO , moisture-free basis. The drying temperature recommended for
3 4 2 4
sp gr 1.84). Dilute to 1 L.
all moisture determinations is 105 to 110°C. Whenever a
3.1.11 Mercuric Chloride Solution (Saturated)—Prepare a sample is weighed out for any determination other than
moisture, it shall be moisture-free. If preferred, the sample may
saturated solution of HgCl .
be dried in a weighing bottle from which the required samples
3.1.12 Potassium Permanganate, Standard Solution
shall be weighed out.
(0.1N)—Dissolve 3.25 g of KMnO in 1000 mL of water.
Allow to stand for one week, filter through an asbestos mat,
6. Blank Determinations
porous glass, or porcelain filter, and keep in a dark place.
Standardize against the National Institute of Standards and 6.1 Make blank determinations on the reagents for each
Technology standard Sample No. 40c of sodium oxalate.
constituent in the whiteware clay and deduct this blank in each
3.1.13 Potassium Permanganate, Standard Solution case. For the determination of the silica (SiO ) blank, approxi-
(0.04N)—Dissolve 2.5 g of KMnO in water and make up to 2 mately 0.25 g of Al O should be added as aluminum chloride.
4 2 3
C323 − 56 (2016)
7. Moisture of 0.1 % methyl red solution. Heat the solution almost to
boiling, and add slowly NH OH (1 + 1) until the indicator has
7.1 Weigh 1.00 g of the sample and heat to constant weight
changed to a yellow color. Boil for several minutes to remove
at a temperature not under 105 nor over 110°C. Record the loss
the excess ammonia. Allow to settle for 30 min and decant
in weight as moisture.
through an open, rapid-filtering acid-washed filter paper, trans-
ferring the precipitate to the paper and washing the beaker and
8. Loss on Ignition
paper several times with a warm 2 % NH Cl solution. Reserve
8.1 Weigh 1.000 g of the moisture-free (105 to 110°C)
the filtrate, “A,” for the determination of calcium oxide (CaO)
sample and heat to constant weight over a blast lamp, or in an
and magnesium oxide (MgO) (Section 14). Return the precipi-
electric muffle furnace, at 900 to 1000°C. Record the loss in
tate and paper to the original beaker, add 50 mL of hot water
weight as the ignition loss.
and 10 mL of HCl (sp gr 1.19). Stir until the precipitate is
dissolved and the paper is well macerated. Dilute to about 200
9. Silica
mL with hot water, precipitate and filter as before. Combine
9.1 Weigh 0.5000 g of the moisture-free (105 to 110°C)
this filtrate “B” with filtrate “A.” Wash the paper and precipi-
sample into a platinum crucible containing about 5 g of
tate with a warm 2 % NH Cl solution. Place the precipitate in
powdered anhydrous Na CO and mix well with a platinum
2 3
a weighed platinum crucible and ignite. Continue the ignition
wire. Cover the mixture with a little more Na CO . Heat
2 3
at 1200°C to constant weight (15 to 20 min is usually
gradually to the full heat of a good burner (1000 to 1100°C)
sufficient). Cool in a desiccator, and weigh with the crucible
maintained for about 1 h until complete solution is obtained.
covered with the lid. The R O consists of the aluminum oxide
2 3
Place the crucible cover on a triangle, and when the melt has
(Al O ), TiO , and Fe O present in the sample. In addition,
2 3 2 2 3
partially cooled, pour it on the lid (Note 3). When cool, place
there may be small amounts of phosphoric anhydride (P O ),
2 5
the crucible and lid in a 150-mL beaker, placing the button on
zirconium oxide (ZrO ), vanadium pentoxide (V O ), and
2 2 5
a watch glass above the beaker. Add 30 mL of HCl (1 + 1).
chromic oxide (Cr O ).
2 3
When solution is complete wash off the crucible and lid with
HCl (1 + 4), taking care to remove all SiO . Place the button in
11. Iron Oxide
the solution. Transfer the contents of the beaker to an evapo-
11.1 Procedure A: Fe O Determined on R O Sample—
rating dish and evaporate to dryness on a steam bath. Bake for
2 3 2 3
Heat the R O precipitate (Note 4) obtained in the determina-
1 h at 110°C. Add 20 to 30 mL of HCl (1 + 1) and 50 mL of hot
2 3
tion of iron, aluminum, and titanium oxides (Section 10), with
water. When all salts have been dissolved, allow to settle for
fused K S O or Na S O until solution is complete. Dissolve
several minutes and then filter through a general-purpose grade
2 2 7 2 2 7
the fusion in 50 mL of H SO (1 + 9) and evaporate to fumes.
acid-washed medium-retention filter paper. Wash the SiO
2 4
Cool, dilute with water, and filter off the SiO , washing with
three times by decantation using 20- to 30-mL portions of first 2
hot water. Reserve the filtrate for the determination of Fe O
hot water, then HCl (1 + 1), then hot water again. Transfer the
2 3
and TiO . Ignite the SiO in a platinum crucible and weigh.
precipitate to th
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