ASTM C146-94a(2009)

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, the 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.

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.

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.