Overview
ISO 2599:2003 - Iron ores: Determination of phosphorus content - Titrimetric method specifies a laboratory titration procedure for measuring phosphorus in iron ores, iron-ore concentrates and agglomerates (including sinter). The method uses hexaammonium heptamolybdate (ammonium molybdate) to precipitate phosphorus as ammonium molybdophosphate and covers the concentration range 0.10 % (m/m) to 5.0 % (m/m) phosphorus. ISO 2599:2003 is intended as a quality-control titrimetric method, not as a referee (dispute-resolution) method.
Key topics and technical requirements
- Principle: acid decomposition of a test portion, separation of insoluble residue, removal of silica (HF/sulfate fusion), collection of phosphorus by precipitation with ammonium molybdate, dissolution of precipitate and back-titration of excess base.
- Applicable range: 0.10–5.0 % P (method tested internationally on samples down to 0.03 % P).
- Reagents: hydrochloric, nitric, perchloric, hydrofluoric and hydrobromic acids; ammonium molybdate solution; iron(III) reagents; standardized NaOH and HNO3 titrant solutions; CO2‑free water per ISO 3696.
- Apparatus & sampling: routine laboratory glassware (ISO 648, ISO 1042); laboratory sample preparation and predried test samples per ISO 3082 and ISO 7764. Particle-size guidance: −100 µm (or −160 µm for ores with combined water/oxidisable phases).
- Procedure controls:
- Analysis at least in duplicate (independent repeats).
- Include a blank and an analysis of a certified reference material (or suitable reference).
- Specific test‑portion masses depend on expected P content (e.g., 1.0 g for low-P samples; 0.5 g for higher-P).
- Modified procedure for samples with >18 mg titanium.
- Quality and precision: Annexes provide flowsheet, repeatability/perm. tolerance derivation, and interlaboratory precision data.
- Safety: uses hazardous acids (HF, HClO4) and oxidizers; follow appropriate lab safety and regulatory limits.
Applications and users
- Practical for mineral laboratory quality control, metallurgical laboratories, ore producers, sinter and pellet plants, and secondary laboratories monitoring phosphorus in feed materials to steelmaking.
- Useful where routine, cost-effective phosphorus determination in iron ore is required for process control, product specification, or incoming material inspection.
- Not suitable as a referee method in legal disputes - use for routine QC, not arbitration.
Related standards
- ISO 3082 - Sampling and sample preparation procedures (iron ores)
- ISO 7764 - Preparation of predried test samples for chemical analysis
- ISO 3696 - Water for analytical laboratory use
- ISO 648 / ISO 1042 - Laboratory glassware specifications
Keywords: ISO 2599, phosphorus determination, iron ores, titrimetric method, ammonium molybdate, ammonium molybdophosphate, iron ore phosphorus analysis, quality control.
