ISO 3429-1976 PDF

Full title and description

ISO 3429:1976 — Sodium fluoride primarily used for the production of aluminium — Determination of iron content — 1,10‑Phenanthroline photometric method. The standard specifies a laboratory analytical procedure for determining iron expressed as Fe2O3 in sodium fluoride intended for aluminium production.

Abstract

Applicable to the determination of iron contents (expressed as Fe2O3) greater than 0.020 % (m/m) in sodium fluoride used in aluminium production. The method covers alkaline fusion (sodium carbonate and boric acid), dissolution of the residue in nitric acid, reduction of iron(III) to iron(II) with hydroxylammonium chloride, formation of the iron(II)-1,10‑phenanthroline coloured complex in a buffered medium (pH 3.5–4.2) and photometric measurement of the complex at about 510 nm.

General information

• Status: Published (International Standard, confirmed).
• Publication date: July 1976.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 71.100.10 (Chemical analysis of metals and ores / inorganic chemical analysis).
• Edition / version: Edition 1 (1976).
• Number of pages: 4.

Details above are taken from the ISO bibliographic record for ISO 3429:1976; the publication was reviewed and confirmed in 2024 and remains the current edition.

Scope

This standard specifies a quantitative photometric method for determining iron impurities in technical-grade sodium fluoride intended chiefly for aluminium production. It is intended for laboratory use where accurate determination of Fe (reported as Fe2O3) above the 0.020 % (m/m) level is required for process control, incoming material inspection and quality assurance in the aluminium industry and associated chemical suppliers.

Key topics and requirements

• Applicable material: sodium fluoride primarily used in aluminium production.
• Applicable range: Fe content (as Fe2O3) > 0.020 % (m/m).
• Sample preparation: alkaline fusion using sodium carbonate and boric acid.
• Dissolution and reduction: dissolution of fusion residue in nitric acid and reduction of Fe(III) to Fe(II) with hydroxylammonium chloride.
• Complex formation: iron(II)-1,10‑phenanthroline complex in buffered medium (pH 3.5–4.2).
• Measurement: photometric determination of the coloured complex at about 510 nm.

These procedural steps and analytical parameters are specified in the standard.

Typical use and users

Primary users are analytical and quality-control laboratories in the aluminium production supply chain, chemical manufacturers and suppliers of technical sodium fluoride, and regulatory or inspection laboratories verifying material conformity. The standard is used for incoming material inspection, supplier qualification and process control where iron impurity levels affect aluminium production quality.

Related standards

Other ISO and industry standards covering sampling, handling of chemical reagents, general photometric methods and the analysis of fluoride-containing materials are commonly used alongside ISO 3429:1976. For laboratory practice, standards on sampling, reagent purity and photometric calibration are relevant; refer to the ICS group 71.100 for related analytical standards.

Keywords

sodium fluoride; iron determination; Fe2O3; 1,10‑phenanthroline; photometric method; alkaline fusion; hydroxylammonium chloride; aluminium production; chemical analysis.

FAQ

Q: What is this standard?

A: ISO 3429:1976 is an International Standard that defines a photometric method using 1,10‑phenanthroline to determine iron content (expressed as Fe2O3) in sodium fluoride intended for aluminium production.

Q: What does it cover?

A: It covers sample preparation (alkaline fusion), chemical reduction and complex formation steps, buffer conditions (pH 3.5–4.2) and photometric measurement at ~510 nm for Fe levels above 0.020 % (m/m).

Q: Who typically uses it?

A: Analytical/quality-control laboratories in the aluminium and chemical industries, material suppliers, and inspection or regulatory laboratories that need to quantify iron impurities in sodium fluoride.

Q: Is it current or superseded?

A: The 1976 edition of ISO 3429 is published and, per the ISO bibliographic record, was reviewed and confirmed in 2024; it remains the current edition.

Q: Is it part of a series?

A: ISO 3429:1976 is a single-part standard addressing this specific analytical method; it is not presented as a multi‑part series. Related analytical standards appear elsewhere within ICS 71.100.10.

Q: What are the key keywords?

A: sodium fluoride, iron, Fe2O3, 1,10‑phenanthroline, photometry, alkaline fusion, analytical chemistry, aluminium industry.