ISO 2597-2:2019

Overview

ISO 2597-2:2019 - "Iron ores - Determination of total iron content - Part 2" specifies two titrimetric methods for measuring total iron content in iron ores, concentrates and agglomerates (including sinter). The methods are mercury‑free and use potassium dichromate as titrant after sequential reduction of Fe(III) by tin(II) chloride and titanium(III) chloride. Excess reductant is oxidized either with dilute potassium dichromate (Method 1) or with perchloric acid (Method 2). Applicable analytical range: 30% to 72% mass fraction Fe.

Key topics and technical requirements

• Scope and applicability
  • Natural iron ores, iron ore concentrates, agglomerates and sinter products with Fe content between 30–72% (mass fraction).
• Sample decomposition
  • Two decomposition routes depending on vanadium content:
    • Acid decomposition (for V ≤ 0.05%): HCl treatment, residue HF/SO4 fusion with potassium disulfate, leach and combine solutions.
    • Fusion‑filtration (for V > 0.05%): fusion with flux mix, leaching, NaOH wash and HCl dissolution.
• Reduction and titration sequence
  • Major Fe(III) reduced with Sn(II), remainder with Ti(III).
  • Excess reductant oxidized by:
    • Method 1: dilute K2Cr2O7, then titration with potassium dichromate using sodium diphenylaminesulfonate indicator.
    • Method 2: perchloric acid oxidation followed by dichromate titration.
• Reagents & apparatus
  • Specifies analytical‑grade reagents (HCl, HF, H2SO4, H3PO4, HClO4, SnCl2, TiCl3, KMnO4, K2Cr2O7) and standard solutions (iron standard, standard dichromate).
  • References laboratory glassware standards (burettes, volumetric flasks, pipettes).
• Quality control and expression of results
  • Procedures for blanks, checks, hygroscopic moisture determination, repeatability and between‑laboratory precision, and test reporting.
• Safety
  • Document includes warnings: hazardous acids (HF, perchloric), oxidizers and high‑temperature fusion steps - appropriate lab safety and waste handling required.

Practical applications

• Routine chemical assay of iron ores for:
  • Mine analytical laboratories and metallurgical/assay labs performing quality control and grade verification.
  • Concentrator plants and sinter production monitoring.
  • Third‑party testing and regulatory compliance where standardized, mercury‑free titrimetric methods are required.
• Useful for establishing production specifications, contractual sampling verification, and laboratory method validation.

Who should use this standard

• Analytical chemists in mining and mineral processing
• QA/QC managers at iron ore producers
• Accredited testing laboratories and inspection bodies
• Standards developers and method validators in metallurgy

Related standards

• ISO 2596 - Determination of hygroscopic moisture in analytical samples
• ISO 3082 - Sampling and sample preparation procedures for iron ores
• ISO glassware standards: ISO 385, ISO 648, ISO 1042
• Other parts of the ISO 2597 series (for broader iron analysis methods)

Keywords: ISO 2597-2:2019, iron ores, total iron content, titrimetric methods, titanium(III) chloride reduction, potassium dichromate, perchloric acid, tin(II) chloride, analytical chemistry, iron ore concentrates.