Overview - ISO 13310:1997 (Iron ores, zinc by FAAS)
ISO 13310:1997 specifies a flame atomic absorption spectrometric (FAAS) method for the determination of zinc content in iron ores. The method is applicable to natural iron ores, concentrates and agglomerates (including sinter) with zinc contents from 0.001 % to 0.5 % (m/m). The standard defines sample preparation, chemical decomposition, iron removal, extraction, instrumental measurement and result calculation, plus precision and quality‑control requirements.
Key topics and technical requirements
- Scope & sampling: Uses predried laboratory samples of minus 100 µm (or minus 160 µm for ores with significant combined water/oxidizable compounds); follow ISO 3081/3082/3083 sampling/preparation standards.
- Sample decomposition: Acid digestion with hydrochloric and hydrofluoric acids, oxidation with nitric acid, evaporation and filtration; residue ignition and fusion with sodium carbonate.
- Iron removal & zinc extraction: Liquid–liquid extraction of iron with 4‑methyl‑2‑pentanone (MIBK), recovery and decomposition of organic phase, recombination of solutions prior to instrumental analysis.
- Reagents & standards: Analytical grade reagents (HCl, HF, HNO3, Na2CO3, MIBK) and zinc stock/working standard solutions as specified in the standard.
- Instrumentation (FAAS): Air–acetylene burner, zinc wavelength 213.9 nm, hollow‑cathode lamp (example setting 8 mA). The standard sets minimum sensitivity, linearity and stability criteria for the spectrometer and recommends procedural checks (blank, CRM).
- Calibration and measurement: Prepare calibration solutions from zinc standards, aspirate in order of increasing absorbance, subtract blank/zero, and use calibration graph to calculate µg Zn/mL in the final test solution.
- Quality control & precision: Duplicate determinations, use of blank tests and certified reference materials (CRMs), and statistical criteria for repeatability and between‑laboratory agreement are specified.
Practical applications and users
- Laboratories analyzing iron ore feedstock, concentrates, sinter and pellets for zinc contamination.
- Metallurgical quality‑control teams monitoring zinc levels that affect smelting, sintering and downstream steelmaking processes.
- Geochemical and mineral analysis labs requiring a standardized FAAS method for comparability between datasets.
- Regulatory and certification bodies validating compliance with product specifications.
Safety and good laboratory practice
The method involves hazardous acids (HF, HCl, HNO3), high temperatures and organic solvents (MIBK). ISO 13310 includes a warning: users must establish appropriate health, safety and waste‑disposal procedures and follow manufacturer instructions for FAAS operation.
Related standards
Normative references in ISO 13310 include ISO 648, ISO 1042 (laboratory glassware), ISO 3081/3082/3083 (iron ore sampling/preparation), ISO 3696 (laboratory water) and ISO 7764 (predried test samples).
Keywords: ISO 13310:1997, iron ores, zinc determination, flame atomic absorption spectrometry, FAAS, analytical method, sample preparation, calibration, laboratory quality control.