ASTM C146-94a(1999)
(Test Method)Standard Test Methods for Chemical Analysis of Glass Sand
Standard Test Methods for Chemical Analysis of Glass Sand
SCOPE
1.1 These test methods cover the chemical analysis of glass sands. They are useful for either high-silica sands (99% + silica (SiO )) or for high-alumina sands containing as much as 12 to 13% alumina (Al O ). Generally nonclassical, the test methods are rapid and accurate. They include the determination of silica and of total R O (see 11.2.4), and the separate determination of total iron as iron oxide (Fe O ), titania (TiO ), chromium oxide (Cr O ), zirconia (ZrO ), and ignition loss. Included are procedures for the alkaline earths and alkalies. High-alumina sands may contain as much as 5 to 6% total alkalies and alkaline earths. It is recommended that the alkalies be determined by flame photometry and the alkaline earths by absorption spectrophotometry.
1.2 These test methods, if followed in detail, will provide interlaboratory agreement of results. Note 1-For additional information, see Test Methods C169 and Practices E50.
1.3 The test methods appear in the following order: Procedures for Referee Analysis: Section Silica (SiO2)--Double Dehydration 10 Total R2O3--Gravimetric 11 Fe2O3, TiO2, ZrO2, Cr2O3, by Photometric Methods and 12-17 Al2O3 by Complexiometric Titration Preparation of the Sample for Determination of Iron 12 Oxide, Titania, Alumina, and Zirconia Iron oxide (as Fe2O3) by 1,10-Phenanthroline Method 13 Titania (TiO2) by the Tiron Method 14 Alumina (Al2O3) by the CDTA Titration Method 15 Zirconia (ZrO2) by the Pyrocatechol Violet Method 16 Chromium Oxide (Cr2O3) by the 1,5-Diphenylcarbo- 17 hydrazide Method Procedures for Routine Analysis: Silica (SiO2)--Single Dehydration 19 Al2O3, CaO, and MgO--Atomic Absorption Spectro- 20-25 photometry Na2O and K2O--Flame Emission Spectrophotometry 26-27 Loss on Ignition (LOI) 28
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.
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Designation: C 146 – 94a (Reapproved 1999)
Standard Test Methods for
Chemical Analysis of Glass Sand
This standard is issued under the fixed designation C 146; 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 responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
1.1 These test methods cover the chemical analysis of glass
bility of regulatory limitations prior to use.
sands. They are useful for either high-silica sands
(99 % + silica (SiO )) or for high-alumina sands containing as
2. Referenced Documents
much as 12 to 13 % alumina (Al O ). Generally nonclassical,
2 3
2.1 ASTM Standards:
the test methods are rapid and accurate. They include the
C 169 Test Methods for Chemical Analysis of Soda-Lime
determination of silica and of total R O (see 11.2.4), and the
2 3
and Borosilicate Glass
separate determination of total iron as iron oxide (Fe O ),
2 3
C 429 Test Method for Sieve Analysis of Raw Materials for
titania (TiO ), chromium oxide (Cr O ), zirconia (ZrO ), and
2 2 3 2
Glass Manufacture
ignition loss. Included are procedures for the alkaline earths
D 1193 Specification for Reagent Water
and alkalies. High-alumina sands may contain as much as 5 to
E 11 Specification for Wire-Cloth Sieves for Testing Pur-
6 % total alkalies and alkaline earths. It is recommended that
poses
the alkalies be determined by flame photometry and the
E 50 Practices for Apparatus, Reagents, and Safety Precau-
alkaline earths by absorption spectrophotometry.
tions for Chemical Analysis of Metals
1.2 These test methods, if followed in detail, will provide
E 60 Practice for Analysis of Metals, Ores, and Related
interlaboratory agreement of results.
Materials by Molecular Absorption Spectrometry
NOTE 1—For additional information, see Test Methods C 169 and
2.2 Other Documents:
Practices E 50. 6
NIST Special Publication 260
1.3 The test methods appear in the following order:
3. Significance and Use
Procedures for Referee Analysis: Section
3.1 These test methods can be used to ensure that the
Silica (SiO )—Double Dehydration 10
chemical composition of the glass sand meets the composi-
Total R O —Gravimetric 11
2 3
Fe O ,TiO , ZrO ,Cr O , by Photometric Methods and 12-17 tional specification required for this raw material.
2 3 2 2 2 3
Al O by Complexiometric Titration
2 3
3.2 These test methods do not preclude the use of other
Preparation of the Sample for Determination of Iron 12
methods that yield results within permissible variations. In any
Oxide, Titania, Alumina, and Zirconia
Iron Oxide (as Fe O ) by 1,10-Phenanthroline Method 13 case, the analyst should verify the procedure and technique
2 3
Titania (TiO ) by the Tiron Method 14
used by means of a National Institute of Standards and
Alumina (Al O ) by the CDTA Titration Method 15
2 3
Technology (NIST) standard reference material or other similar
Zirconia (ZrO ) by the Pyrocatechol Violet Method 16
Chromium Oxide (Cr O ) by the 1,5-Diphenylcarbo- 17 material of known composition having a component compa-
2 3
hydrazide Method
rable with that of the material under test. A list of standard
reference materials is given in the NIST Special Publication
Procedures for Routine Analysis:
260, current edition.
Silica (SiO )—Single Dehydration 19
Al O , CaO, and MgO—Atomic Absorption Spec- 20–25
2 3
4. Photometers and Photometric Practice
trophotometry
Na O and K O—Flame Emission Spectrophotometry 26-27 4.1 Photometers and photometric practice prescribed in
2 2
Loss on Ignition (LOI) 28
these test methods shall conform to Practice E 60.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
Annual Book of ASTM Standards, Vol 15.02.
Annual Book of ASTM Standards, Vol 11.01.
1 4
These test methods are under the jurisdiction of ASTM Committee C-14 on Annual Book of ASTM Standards, Vol 14.02.
Glass and Glass Products and are the direct responsibility of Subcommittee C14.02 Annual Book of ASTM Standards, Vol 03.05.
on Chemical Properties and Analysis. Standard samples available from the National Institute of Standards and
Current edition approved Nov. 15, 1994. Published January 1995. Originally Technology are listed in U.S. Dept. of Commerce, NIST, Special Publication 260
published as C 146 – 39 T. Last previous edition C 146 – 94. (current edition), Washington, DC 20234.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C 146
5. Purity of Reagents on a 850-μm (No. 20) sieve, these shall be sieved out, crushed
(without contamination) so as to pass the sieve, and then mixed
5.1 Reagent grade chemicals shall be used throughout.
back into the laboratory sample before riffling.
Unless otherwise indicated, it is intended that reagents shall
conform to the specifications of the Committee on Analytical
9. Precision and Bias
Reagents of the American Chemical Society, where suchspeci-
9.1 Precision—The probable precision of results that can be
fications are available. Other grades may be used, provided it
expected by the use of procedures described in these test
is first ascertained that the reagent is of sufficiently high purity
methods is shown in the following tabulation. Precision is
to permit its use without lessening the accuracy of the
given as absolute error and is dependent on the quantity of the
determination.
constituent present as well as the procedure used.
5.2 Unless otherwise indicated, references to water shall be
Probable Precision of Results, Weight %
understood to mean reagent water as defined by Type I, II, or
Constituent Referee Analysis Routine Analysis
III of Specification D 1193.
SiO (99 %) 60.1 60.25
6. Concentration of Acids and Ammonium Hydroxide SiO (85–90 %) 60.1 60.25
R O (1 %) 60.05 60.10
2 3
(NH OH)
R O (10–15 %) 60.1 60.15
2 3
6.1 When acids and ammonium hydroxide are specified by Al O (1 %) 60.05 60.10
2 3
Al O (10–15 %) 60.1 60.1
2 3
name or chemical formula only, concentrated reagents of the
Fe O 60.003 .
2 3
following percent concentrations are intended:
TiO 60.005 .
ZrO 60.001 to 0.005 .
Sp Gr % 2
Cr O 60.0001 to 0.001 .
2 3
CaO . 60.001
Hydrochloric acid (HCl) 1.2 36 to 38
MgO . 60.001
Hydrofluoric acid (HF) 1.2 48 to 51
Na O . 60.001
Nitric acid (HNO ) 1.4 69 to 71 2
K O . 60.001
Perchloric acid (HClO ) 1.8 70 to 72
Sulfuric acid (H SO ) 1.8 95 to 98
2 4
9.2 Bias—Standard reference materials or other similar
Ammonium hydroxide (NH OH) 0.9 28 to 30
materials of known composition should be analyzed whenever
6.2 Concentrations of diluted acids and NH OH, except
possible to determine the bias of the results.
when standardized, are specified as a ratio stating the number
of volumes of the concentrated reagent to be added to a given
PROCEDURES FOR REFEREE ANALYSIS
number of volumes of water, as in the following example: HCl
10. Silica (SiO ) by the Double Dehydration Method
(1 + 99) means 1 volume of concentrated HCl (sp gr 1.19)
added to 99 volumes of water.
10.1 Weigh 1.000 g of the powdered sample and 2.0 g of
anhydrous sodium carbonate (Na CO ) into a clean 75-mL
2 3
7. Filter Papers 9
platinum dish (Note 2); mix well with a platinum or Nichrome
7.1 Throughout these test methods, filter papers will be
wire. Tap the charge so it lies evenly in the bottom of the dish.
designated as “coarse,” “medium,” or “fine” without naming
Cover evenly with an additional 1.0 g of Na CO . Cover with
2 3
brands or manufacturers. All filter papers are of the double- the platinum lid and heat first at a dull red heat over a clean
acid-washed ashless type. “Coarse” filter paper refers to the
oxidizing flame; gradually raise the temperature until a clear
porosity commonly used for the filtration of aluminum hydrox- melt is obtained. Properly carried out, little or no spattering
ide. “Medium” filter paper refers to that used for filtration of
should occur, and the fusion can be performed in 3 to 4 min.
calcium oxalate, and “fine” filter paper to that used for barium When melted, rotate the melt to spread it evenly over the
sulfate.
bottom and lower sides of the dish, gradually withdrawing
from the flame. Cover and cool to room temperature. During
8. Preparation of Sample
fusion, the dish should be handled at all times with platinum-
8.1 General Considerations—The acquisition and prepara- tipped tongs and the fusion performed with a platinum (pref-
tion of the sample shall follow the principles stated in Test erably 90 % platinum and 10 % rhodium alloy) or silica
Method C 429. triangle.
8.2 The laboratory sample is reduced for analysis to 10 to 20
NOTE 2—To obtain accurate repeat weighings, platinum ware must be
g by use of a small riffle with openings preferably of 6.4-mm
kept scrupulously clean on the outside of the vessel as well as on the
( ⁄4-in.) size. The analytical sample is then ground in an agate
inside. It should be polished brightly with fine, round grain sand and
mortar to pass a 150-μm (No. 100) sieve. If the laboratory
protected from dirty surfaces. It is recommended that porcelain plates be
sample as received contains any large particles that are retained used for cooling fusions, and that platinum be set on paper towels or other
clean material during filtration.
10.2 Add 20 to 25 mL of HCl (1 + 1) under the platinum
Reagent Chemicals, American Chemical Society Specifications, American
cover and digest on a steam bath or hot plate until the melt has
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
completely disintegrated; it is also possible to digest the melt in
listed by the American Chemical Society, see Analar Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD. Nichrome is a registered trademark of the Driver-Harris Co., 308 Middlesex
Requirements for sieves are given in ASTM Specification E 11. St., Harrison, NJ 07029.
C 146
the cold HCl overnight. Police and rinse the lid with a fine jet 11.2.1 Weigh a suitable weight of sample into an 80- to
of water; rinse down the sides of the dish and evaporate to 100-mL platinum dish, moisten, and add 10 mL of HF for each
dryness on a steam bath or under an infrared lamp. Keep the gram of sample taken; add 4 mL of H SO (1 + 1) and
2 4
dish covered with a raised cover glass during evaporation. evaporate to the first fuming of H SO (Note 3). Cool,
2 4
When evaporation is complete (absence of HCl), cool, drench carefully wash down the sides of the dish with a minimum of
the residue with 5 mL of HCl, and then add 20 mL of hot water. water, and evaporate to the cessation of H SO fumes. Cool,
2 4
Digest for 5 min and filter through a 9-cm medium filter paper. add 10 to 15 mL of HCl (1 + 1), 20 mL of hot water, and digest
Catch the filtrate in a 250-mL platinum dish. Transfer the hot until the salts are in solution. If they do not dissolve readily,
precipitated silica to the filter with the aid of a policeman and transfer to a beaker, police the dish, and boil the solution until
a bit of paper pulp, and wash the precipitate and paper twelve the sulfates have dissolved (Note 4).
times with hot 2 % HCl. Transfer the paper and precipitate to
NOTE 3—Some sands may contain small amounts of organic matter as
the dish used for fusion and dehydration and reserve for
shown by the presence of carbon or carbonaceous material in the
subsequent ignition. Wipe the stirring rod and the periphery of
concentrated H SO . If this is the case, add 2 to 3 mL of HNO and 10 to
2 4 3
the funnel with a piece of damp filter paper, and add to the dish 15 drops of HClO , and proceed.
containing the precipitate for ignition. NOTE 4—High-alumina sands are generally mixtures of quartz and
aluminum silicates of the feldspar group. Some of these silicates can
10.3 Evaporate the filtrate to dryness on the steam bath or
contain barium. If a fine, white, insoluble precipitate persists, it is
under an infrared lamp. When dry, cool, drench with 10 mL of
probably barium sulfate. In this case, partially neutralize the HCl until the
HCl (1 + 1), and again evaporate just to dryness; then bake in
solution is about 1 to 2 % acid, add about ten drops of H SO (1 + 1) and
2 4
a drying oven at 105°C for 30 min. Cool, drench with 5 mL of
boil gently for about 30 min. Cool, and after 1 to 2 h, filter the solution
HCl, and add 20 mL of hot water and a small bit of filter pulp.
through a fine paper. The precipitate may be ignited and weighed and
Digest hot for 5 min and filter through a 7-cm fine paper. Police
subsequently tested for barium. If the precipitate is not barium sulfate, it
the dish with the aid of a bit of paper pulp and wash precipitate should be tested for silica. If the precipitate is neither of these, it can be
considered R O and added to the R O found by ammonia precipitation.
and paper eight times with hot 2 % HCl. Transfer the paper and 2 3 2 3
precipitate to the dish containing the initial precipitation. Wipe
11.2.2 If the expected R O is about 10 mg, dilute the
2 3
the stirring rod and the periphery of the funnel with a piece of
sample to about 75 to 100 mL; if much larger, dilute to about
damp filter paper, and add to the dish containing the precipitate
200 to 250 mL. Add approximately2gofNH Cl, heat to
for ignition.
boiling, add three to four drops of methyl red indicator solution
10.4 Partially cover the dish with its platinum lid, but leave
and precipitate the R O with the addition of NH OH (1 + 1).
2 3 4
enough space so air can circulate during ignition. Place the dish
Add the NH OH slowly, stirring to obtain a sharp end point;
in a cold muffle furnace, and bring the temperature to 1200°C
finally add about four drops in excess for small amounts of
for 30 min. Carefully and completely cover the dish before
precipitate and up to eight drops for large amounts. Boil the
removing it from the furnace and transfer to a desiccator. Cool
solution for about 2 min and filter through a coarse paper; there
to room temperature and weigh the covered dish (W ). Moisten
is no need to transfer quantitatively all the precipitate at this
the silica with 1 to 2 mL of water and add 4 to 5 mL of HF and
time. Wash the precipitate three to four times with hot 2 %
0.5 g of oxalic acid crystals. Evaporate to dryness on a sand
NH Cl made neutral to methyl r
...
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