ISO 6467:2018

Overview

ISO 6467:2018 specifies a potentiometric titration method for the determination of vanadium content in ferrovanadium. The standard applies to ferrovanadium materials with vanadium mass fractions between 35.0 % and 85.0 %. This second edition (2018) updates procedure, precision data and the applicable vanadium range from the earlier 1980 edition.

Key topics and technical requirements

• Principle: Dissolve a test portion in nitric and sulfuric acids; oxidize vanadium(IV) to vanadium(V) with potassium permanganate; destroy excess oxidant with potassium nitrite and urea; then reduce V(V) to V(IV) by titration with standard ammonium iron(II) sulfate while monitoring the end-point potentiometrically.
• Applicability range: Vanadium content between 35.0 % and 85.0 % (mass fraction).
• Reagents: Analytical-grade reagents and grade 2 water (ISO 3696). Key reagents include potassium permanganate, potassium nitrite, phosphoric/nitric/sulfuric acids, urea, potassium dichromate (for standardization) and ammonium iron(II) sulfate as titrant.
• Apparatus: Class A volumetric glassware (ISO 648, ISO 1042), a precision potentiometer with platinum indicating electrode and a Hg/Hg2SO4/K2SO4 (saturated) or Ag/AgCl/KCl (saturated) reference electrode, magnetic stirrer and burettes.
• Sample preparation: Use powder passing a 250 μm sieve, prepared per ISO 3713. Typical test portion is 0.5000 g ± 0.0001 g.
• Result expression: Vanadium content is calculated from titrant volume, titrant concentration and test portion mass; the atomic mass factor 50.94 is used in the formula provided in the standard.
• Precision: Inter-laboratory validation (eight labs) produced repeatability and reproducibility limits. Example values: at ~47 % V, r = 0.175 and R = 0.478; at ~78 % V, r = 0.305 and R = 0.624. Interpretation follows ISO 5725-2.

Applications and users

ISO 6467:2018 is primarily intended for:

• Metallurgical laboratories performing compositional analysis of ferroalloys.
• Ferrovanadium producers and quality control teams verifying vanadium content for product certification and trade.
• Third‑party testing and inspection bodies that require a standardized, traceable method for vanadium assay.
• Research laboratories studying ferrovanadium chemistry or process optimization.

Practical uses include incoming material inspection, product specification verification, compliance testing for trade and process control in steelmaking where ferrovanadium is used as an alloying addition.

Related standards

• ISO 3713 - Sampling and preparation of ferroalloy samples
• ISO 3696 - Water for analytical laboratory use
• ISO 648 / ISO 1042 - Laboratory volumetric glassware specifications
• ISO 5725-2 - Accuracy (trueness and precision) - determination of repeatability and reproducibility

Keywords: ISO 6467, ferrovanadium, vanadium determination, potentiometric method, ammonium iron(II) sulfate, metallurgical analysis, ferroalloys, precision, repeatability, reproducibility.