ISO 3392-1976 rus PDF

Full title and description

St ISO 3392-1976 (ISO 3392:1976) — Cryolite, natural and artificial, and aluminium fluoride for industrial use — Determination of water content — Electrometric method. This document specifies an electrometric (Karl Fischer, direct titration) procedure and a complementary loss‑on‑ignition determination at 550 °C to calculate water content accounting for water and hydrogen fluoride formed by pyrohydrolysis.

Abstract

The standard describes a combined approach: (1) measurement of mass loss at 550 °C (which includes free water and water produced as HF by pyrohydrolysis) and (2) direct electrometric (Karl Fischer) determination of water released at 550 °C. The difference between the two results (accounting for 2 HF = 1 H2O) is used to calculate the total water content. A diagram of the test apparatus and references (including ISO 760) are provided.

General information

• Status: Withdrawn.
• Publication date: September 1976.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 71.060.50 (Chemical analysis of raw materials for aluminium production).
• Edition / version: Edition 1 (1976).
• Number of pages: 5.

Key bibliographic and lifecycle data above are taken from ISO's bibliographic record for ISO 3392:1976.

Scope

This standard applies to the simultaneous determination of (a) the loss of mass at 550 °C (representing the sum of unreacted water plus hydrogen fluoride formed by pyrohydrolysis) and (b) the mass of water released at 550 °C determined by direct electrometric (Karl Fischer) titration, for cryolite (natural and artificial) and aluminium fluoride intended for industrial use. It provides the calculation to combine both results and gives a diagram of the test apparatus.

Key topics and requirements

• Simultaneous determination using loss‑on‑ignition at 550 °C and Karl Fischer electrometric titration.
• Correction for hydrogen fluoride formed by pyrohydrolysis (stoichiometry 2 HF = 1 H2O).
• Reference to ISO 760 (Karl Fischer titration principles and reagents).
• Specification of apparatus layout and procedural steps for sample treatment and calculation of water content.

These requirements are summarized from the standard's method description and abstract.

Typical use and users

Laboratories and quality control departments in aluminium production and processing industries, suppliers and purchasers of cryolite and aluminium fluoride, and analytical chemists concerned with moisture/water determination in inorganic fluoride materials. The method is relevant for cases where pyrohydrolysis can produce hydrogen fluoride that would otherwise bias simple moisture determinations.

Related standards

ISO 760 (Karl Fischer titration) is referenced within the method. Other related ISO methods for fluoride and aluminium salts, and neighbouring ISO standards addressing determination of moisture or related constituents in aluminium‑industry raw materials (for example ISO 3391, ISO 3393 and other ISO chemical analysis standards listed in the ISO catalogue) provide complementary procedures and context. Note: ISO 3392:1976 has been withdrawn; consult current ISO catalogues or national adoptions for up‑to‑date methods.

Keywords

cryolite; aluminium fluoride; water content; moisture determination; Karl Fischer; electrometric titration; pyrohydrolysis; loss on ignition; aluminium industry; ISO 3392.

FAQ

Q: What is this standard?

A: ISO 3392:1976 specifies an electrometric (Karl Fischer) method combined with a loss‑on‑ignition determination at 550 °C for assessing water content in natural and artificial cryolite and aluminium fluoride used industrially.

Q: What does it cover?

A: It covers the procedure to obtain two complementary measurements (mass loss at 550 °C and direct Karl Fischer titration), the calculation to reconcile the two results accounting for hydrogen fluoride formation, and a diagram of the required apparatus.

Q: Who typically uses it?

A: Analytical and quality control laboratories in the aluminium production chain, materials suppliers, and chemists performing moisture and fluoride analyses on raw materials for aluminium manufacture.

Q: Is it current or superseded?

A: ISO 3392:1976 is listed as withdrawn (Edition 1, 1976). The ISO bibliographic record marks it as withdrawn; catalog listings show it was withdrawn and not maintained as a current active standard — users should consult current ISO publications or national standards bodies for a presently valid method.

Q: Is it part of a series?

A: It is one of several ISO chemical analysis standards related to materials for aluminium production and to moisture/water determination methods; it references ISO 760 (Karl Fischer). Other adjacent ISO items in the 3300–3400 range cover related determinations for aluminium‑industry materials.

Q: What are the key keywords?

A: cryolite, aluminium fluoride, water content, Karl Fischer, electrometric titration, pyrohydrolysis, loss on ignition, ISO 3392.