3.1 These test methods can be used to ensure that the chemical composition of the glass sand meets the compositional specification required for this raw material.

3.2 These test methods do not preclude the use of other methods that yield results within permissible variations. In any case, the analyst should verify the procedure and technique used by means of a National Institute of Standards and Technology (NIST) standard reference material or other similar material of known composition having a component comparable with that of the material under test. A list of standard reference materials is given in the NIST Special Publication 260, current edition.

1.1 These test methods cover the chemical analysis of glass sands. They are useful for either high-silica sands (99 % + silica (SiO₂)) or for high-alumina sands containing as much as 12 to 13 % alumina (Al₂O₃). Generally nonclassical, these test methods are rapid and accurate. They include the determination of silica and of total R₂O₃  (see 11.2.4), and the separate determination of total iron as iron oxide (Fe₂O₃), titania (TiO₂), chromium oxide (Cr₂O₃), zirconia (ZrO₂), 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 These 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
  Al₂O₃ by Complexiometric Titration

12 – 17

 Preparation of the Sample for Determination of Iron
  Oxide, Titania, Alumina, and Zirconia

12

 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-
  hydrazide Method

17

Procedures for Routine Analysis:

 Silica (SiO₂)—Single Dehydration

19

 Al₂O₃, CaO, and MgO—Atomic Absorption Spec-
  trophotometry

20–25

 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 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.