【国外标准】 Standard Test Methods for Chemical and Atomic Absorption Analysis of Uranium-Ore Concentrate

4.1 The test methods in this standard are designed to show whether a given material meets the specifications prescribed in Specification C967.4.2 Because of the variability of matrices of uranium-ore concentrate and the limited availability of suitable reference or calibration materials, the precision and bias of these test methods should be established by each individual laboratory that will use them. The precision and bias statements given for each test method are those reported by various laboratories and can be used as a guideline.4.3 Instrumental test methods such as X-ray fluorescence and emission spectroscopy can be used for the determination of some impurities where such equipment is available.1.1 These test methods cover procedures for the chemical and atomic absorption analysis of uranium-ore concentrates to determine compliance with the requirements prescribed in Specification C967.1.2 The analytical procedures appear in the following order:  SectionsUranium by Ferrous Sulfate Reduction—Potassium Dichromate  Titrimetry    9Nitric Acid-Insoluble Uranium  10 to 18Extractable Organic Material  19 to 26Determination of Arsenic  27Carbonate by CO2 Gravimetry  28 to 34Fluoride by Ion-Selective Electrode  35 to 42Halides by Volhard Titration  43 to 50Phosphorus by Spectrophotometry  52 to 60Determination of Silicon  61Determination of Thorium  62Calcium, Iron, Magnesium, Molybdenum, Titanium, and Vana- dium by Atomic Absorption Spectrophotometry  63 to 72Potassium and Sodium by Atomic Absorption  Spectrophotometry  73 to 82Boron by Spectrophotometry 83 to 921.3 The values stated in SI units are to be regarded as 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. A specific precautionary statement is given in Section 7.1.5 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.