ISO 7692:2025

Overview

ISO 7692:2025 specifies a titrimetric method for the determination of titanium content in ferrotitanium. The procedure is intended for ferrotitanium with a titanium mass fraction between 20.0 % and 80.0 %. The standard defines sample preparation, reagents, apparatus, the analytical procedure (dissolution, separation, reduction, titration), calculation and reporting of results, and includes precision information and informative annexes.

Key topics and technical requirements

• Scope and applicability: Designed for ferrotitanium materials with Ti content 20–80 % by mass.
• Principle: Dissolve the test portion in a mixture of sulfuric, fluoboric, nitric and hydrochloric acids; separate interfering elements (Cr, V, Mo, Sn) by precipitation of titanium hydroxide in presence of hydrogen peroxide; reduce Ti(III/IV) to metallic Ti using aluminium under a carbon dioxide or nitrogen atmosphere; titrate the reduced titanium with standard ammonium iron(III) sulfate using thiocyanate as indicator.
• Sample and test portion: Powder passing a 125 μm sieve per ISO 3713; test portion mass 0.5000 g ± 0.0001 g.
• Reagents and standards: Includes specified acid grades, hydrogen peroxide (30 %), sodium hydroxide solutions, aluminium foil (≥99.5 %), titanium standard solution (1.0 mg/ml prepared from TiO2 or titanium sponge or CRMs), and ammonium iron(III) sulfate standard volumetric solution.
• Apparatus: Class A volumetric glassware; conical flasks; Bunsen valve or condenser for inert atmosphere; magnetic stirrer with PTFE bar; titration setup suitable for nitrogen/CO2 atmosphere.
• Quality controls: Run a blank test and analyse a certified reference material (CRM) of the same ferrotitanium type in parallel. When multiple samples are processed together, one blank and/or one CRM may cover the batch under specified conditions.
• Reporting and precision: Clause on expression of results and precision is included; Annexes A–C provide verification data, graphical precision representation, and an acceptance flow chart for results.

Applications and practical value

• Routine quality control and compositional verification in ferroalloy production and trading.
• Metallurgical and analytical laboratories performing elemental analysis of ferrotitanium.
• Regulatory, procurement and QA/QC teams that require standardized, traceable methods for titanium content determination.
• Useful for export/import compliance, material certification, and research where accurate Ti quantification in ferroalloys is required.

Who should use this standard

• Ferroalloy manufacturers and processors
• Analytical and metallurgical laboratories (QA/QC chemists)
• Standards and conformity assessment bodies
• Purchasing, specification and inspection personnel in steel and alloy industries

Related standards

• ISO 3713 - sampling and preparation of ferroalloy samples
• ISO 3696 - water for analytical laboratory use
• ISO 385, ISO 648, ISO 1042 - laboratory glassware specifications

Keywords: ISO 7692:2025, ferrotitanium, titanium determination, titrimetric method, titration, ammonium iron(III) sulfate, ferroalloys, analytical method, QA/QC.