Formerly under the jurisdiction of Committee C21 on Ceramic Whitewares and Related Products, these test methods were withdrawn in February 2024. This standard is being withdrawn without replacement due to its limited use by industry.

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.

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.