ASTM C791 : 83(2000)

Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Boron Carbide

Standard Details

1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade boron carbide powder and pellets to determine compliance with specifications.

1.2 The analytical procedures appear in the following order:

	Sections
Total Carbon by Combustion and Gravimetry	7-17
Total Boron by Titrimetry	18-28
Isotopic Composition by Mass Spectrometry	29-38
Chloride and Fluoride Separation by Pyrohydrolysis	39-45
Chloride by Constant-Current Coulometry	46-54
Fluoride by Ion-Selective Electrode	55-63
Water by Constant-Voltage Coulometry	64-72
Impurities by Spectrochemical Analysis	73-81
Soluble Boron by Titrimetry	82-95
Soluble Carbon by a Manometric Measurement	96-105
Metallic Impurities by a Direct Reader Spectrometric Method	106-114

1.3 This method covers the determination of total carbon in nuclear-grade, boron carbide in either powder or pellet form.

1.4 This method covers the determination of total boron in samples of boron carbide powder and pellets. The recommended amount of boron for each titration is 100 10 mg.

1.5 This method covers the determination of the isotopic composition of boron in nuclear-grade boron carbide, in powder and pellet form, containing natural to highly enriched boron.

1.6 This method covers the separation of up to 100 g of halides per gram of boron carbide. The separated halides are measured using other methods found in this standard.

1.7 This method covers the measurement of chloride after separation from boron carbide by pyrohydrolysis. The lower limit of the method is about 2 g of chloride per titration.

1.8 This method covers the measurement of fluoride after separation from boron carbide by pyrohydrolysis. The lower limit of the method is about 2 g of fluoride per measurement.

1.9 This method covers the determination of water in boron carbide in either powder or pellet form. The lower limit of the method is 5 g of water.

1.10 This method covers the determination of 14 impurity elements in boron carbide in either powder or pellet form.

1.11 This method covers the determination of soluble boron in boron carbide. Soluble boron is defined as that boron dissolved under the conditions of the test.

1.12 This method covers the determination of soluble carbon in boron carbide. The lower limit of the method is 0.02 % with a 100-mg sample. Soluble carbon is defined as that carbon oxidized by the sodium dichromate-sulfuric acid solution under the conditions of this method.

1.13 This method is applicable to the determination of metallic impurities in samples of boron carbide powder and pellets. From 20 to 5000 g of many of the impurities per gram of sample can be determined.