【国外标准】 Standard Test Method for Determination of Calcium Fluoride in Fluorspar by EDTA Complexometric Titrimetry

5.1 Fluorspar is used as a flux in the steelmaking and glass industries, and in the manufacture of HF.5.2 This test method is intended to be used for compliance with compositional specifications for calcium fluoride content. It is assumed that all who use these procedures will be trained analysts capable of performing common laboratory procedures skillfully and safely. It is expected that work will be performed in a properly equipped laboratory and that proper waste disposal procedures will be followed. Appropriate quality control practices must be followed such as those described in Guide E882.1.1 This test method covers the determination of calcium fluoride in acid-grade fluorspar and other types of fluorspar that can be rendered soluble by the procedure described in the test method.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This test method has been evaluated in accordance with Practice E1601 and Guide E1763. Unless otherwise noted in the precision and bias section, the lower limit in the scope of each method specifies the lowest analyte content that may be analyzed with acceptable error (defined as a nominal 5 % risk of obtaining a 50 % or larger relative difference in results on the same test sample in two laboratories).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.