1 Scope
This Standard specifies the determination of the lead content in iron ores by the flame atomic absorption spectrometric method.
This Standard is applicable to determination of the lead contents in natural iron ores, iron ore concentrates and agglomerates, including sintered products, with the determination range of 0.001%~0.500% (m/m).
2 Normative References
The following standards contain provisions which, through reference in this Standard, constitute provisions of this Standard. For dated references, subsequent amendments to (excluding correction to) or modified editions do not apply, but all standards subject to revision, and parties to agreements based on this Standard are encouraged to investigate the possibility of applying the most recent editions of these standards indicated below. For undated references, the latest editions apply to this Standard.
GB/T 6682 Water for Analytical Laboratory Use - Specification and Test Methods (neq ISO 3697:1987)
GB/T 6730.1 Methods for Chemical Analysis of Iron Ores - Preparation of Predried Test Samples for Chemical Analysis (idt ISO 7764:1985)
GB/T 10322.1 Iron Ores - Sampling and Sample Preparation Procedures (idt ISO 3082:1998)
GB/T 12806 Laboratory Glassware - One-mark Volumetric Flasks (eqv ISO 1042:1983)
GB/T 12808 Laboratory Glassware - One-Mark Pipettes (eqv ISO 648:1977)
3 Principle
The sample is decomposed with hydrochloric acid and hydrofluoric acid to remove the silicon dioxide and oxidize the nitric acid. The salts are dissolved with hydrochloric acid, and filtered. The residue is melted with sodium carbonate after being charred and burnt. The melt is leached in the hydrochloric acid and the residue recovery solution is reserved. The iron is extracted in the filtrate with 4- methyl-2-pentanone (MIBK) and the water phase is recovered. The residual 4- methyl-2-pentanone (MIBK) is destroyed with nitric acid and evaporated to dryness, and the salts is dissolved with hydrochloric acid and combined with the residue recovery solution. At the atomic absorption spectrometer, the absorbance is measured with the air-acetylene flame at a wavelength of 283.3 nm.
Foreword I
1 Scope
2 Normative References
3 Principle
4 Regents and Materials
5 Apparatus
6 Sampling and Sample Preparation
7 Analytical Procedure
8 Result Calculation
9 Test Report
Appendix A (Normative) Flowsheet of Procedure for Acceptance of Analytical Values for Samples
Appendix B (Informative) Derivation of Repeatability and Permissible Tolerance Equations
Appendix C (Informative) Precision Data Obtained by International Analytical Trials
