Overview
ISO 9683-2:2009 specifies flame atomic absorption spectrometric (AAS) methods for the determination of the mass fraction of vanadium (V) in iron ores. It defines two analytical procedures:
- Method 1: for vanadium mass fractions from 0.004 % to 0.06 % (low-level determination, includes a solvent extraction step),
- Method 2: for vanadium mass fractions from 0.06 % to 0.5 % (higher range, direct measurement with iron background matrix).
The standard applies to natural iron ores, iron ore concentrates and agglomerates (including sinter products) and includes sample preparation, reagents, apparatus, measurement and reporting requirements.
Key Topics and Technical Requirements
- Sample preparation: Use a laboratory sample with particle size minus 100 µm (or minus 160 µm for ores with significant combined water/oxidizable compounds) and predry as per ISO 7764; sampling per ISO 3082.
- Dissolution/decomposition: Acid digestion (HCl, HF, HNO3) with evaporation, boric acid treatment and fusion of residue with sodium carbonate when required.
- Method 1 specifics: Oxidation with cerium(IV), formation of vanadium complex with phosphoric acid and sodium tungstate, extraction into a 1:1 mixture of 1-pentanol and MIBK, back-extraction with ascorbic acid.
- Method 2 specifics: Use of an iron background solution and direct measurement after dissolution and addition of aluminium chloride/buffering (boric acid).
- Measurement: Aspirate prepared solution into a dinitrogen oxide/acetylene flame AAS; measure absorbance at approximately 318.5 nm using a vanadium hollow-cathode lamp (typical 10 mA).
- Instrument performance criteria: Minimum sensitivity (absorbance ≥ 0.25 for the highest calibration), calibration linearity (top 20% slope ≥ 0.7 of bottom 20% slope), and stability limits (standard deviations of calibration absorbances within specified % limits).
- Quality control & precision: The standard prescribes duplicate determinations, blanks, calibration solutions, acceptance flowsheet and annexes with repeatability and between-laboratory precision guidance.
Applications and Who Uses ISO 9683-2:2009
- Mining and mineral processing laboratories for routine determination of vanadium in ores and concentrates.
- Quality control teams at iron ore beneficiation plants and sinter/agglomeration facilities.
- Metallurgical and contract testing laboratories performing chemical analyses for product specification and trade.
- Standards and compliance officers ensuring traceable, reproducible vanadium assay results in supply chains.
Practical benefits include standardized sample handling, validated AAS procedures for different concentration ranges, and documented precision/acceptance criteria for reporting analytical results.
Related Standards
For laboratories implementing ISO 9683-2:2009, follow the safety warnings and reagent/apparatus specifications detailed in the standard to ensure accurate and compliant vanadium determinations.
Open preview (PDF)Iron ores — Determination of vanadium — Part 2: Flame atomic absorption spectrometric methods