Overview
ISO 13313:2017 specifies a flame atomic absorption spectrometric (FAAS) method for the determination of the mass fraction of sodium in iron ores. The standard covers natural iron ores, iron ore concentrates and agglomerates (including sinter products) with sodium contents in the range 0.0025 % to 0.50 %. The method describes sample preparation, chemical decomposition, instrument calibration and result reporting for reliable sodium analysis in metallurgical and mining laboratories.
Key Topics and Requirements
- Scope and applicability: Mass fraction range 0.0025 %–0.50 %; applicable to natural ores, concentrates and agglomerates.
- Principle: Decompose a test portion using hydrochloric acid (HCl) and hydrofluoric acid (HF), evaporate to dryness, redissolve in HCl and aspirate the final solution into an air/acetylene flame for atomic absorption measurement.
- Sampling and sample prep: Use a laboratory sample prepared in accordance with ISO 3082; predried test samples prepared per ISO 7764 (or ISO 2596 for ores with significant combined water/oxidizable compounds).
- Reagents and standards: Analytical-grade reagents and Grade 2 water (ISO 3696); specified HCl and HF grades, a background iron solution, and a 10 µg Na/ml sodium standard solution.
- Apparatus and contamination control: Prefer PTFE vessels, PTFE-coated stirring bars, PTFE digestion bombs and plastic ware to minimize sodium contamination. Glass equipment is to be avoided except where allowed. Detailed cleaning and blank-testing procedures are required.
- Instrument performance criteria: FAAS minimum sensitivity (absorbance ≥ 0.25 for the highest calibration standard), linearity checks and stability limits for repeated measurements are specified.
- Quality control and precision: Duplicate independent determinations are required; the standard includes procedures for blanks, calibration solutions, repeatability, between-laboratory precision and acceptance of analytical values.
Applications and Who Uses It
ISO 13313:2017 is used by:
- Laboratory analysts in mining and metallurgical QA/QC labs
- Process control and assay labs for iron ore processing and sintering operations
- Suppliers and purchasers validating material specifications and contractual sodium limits
- Accreditation bodies and standardization committees for method validation
Typical applications include sodium monitoring for product specification compliance, process optimization in pelletizing/sintering, and analytical verification of concentrates.
Related Standards
Normative references and related ISO standards include:
Note: ISO 13313:2017 contains safety warnings - HF and HCl are hazardous; follow appropriate laboratory safety and regulatory requirements.