ISO 2598-2-1992 PDF

Full title and description

Iron ores — Determination of silicon content — Part 2: Reduced molybdosilicate spectrophotometric method. This part specifies a spectrophotometric procedure (reduction to molybdenum blue) for the determination of silicon in natural iron ores, concentrates and agglomerates.

Abstract

The standard describes decomposition of the test portion by fusion (sodium tetraborate), treatment with dilute nitric acid, formation of a molybdatosilicate complex by addition of ammonium molybdate, reduction to molybdenum blue (ascorbic acid) and measurement of absorbance (approximately 600 nm). It is intended for silicon contents from about 0.10 % to 5.0 % by mass and is applicable to ores, concentrates and sinter products, including ores containing fluorine.

General information

• Status: Published (International Standard); reviewed and confirmed in recent systematic reviews.
• Publication date: December 1992 (Edition 1, 1992-12).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 73.060.10 — Iron ores.
• Edition / version: Edition 1 (1992).
• Number of pages: 8 pages (original publication).

Scope

Specifies a reduced molybdosilicate spectrophotometric method for determining silicon in iron ores, ore concentrates and agglomerates. The procedure covers silicon contents from 0.10 % to 5.0 % by mass and is especially suitable for ores that contain fluorine (fluorine does not interfere with the determination by this method). The method includes required sample decomposition, reagent additions, reduction step and spectrophotometric measurement.

Key topics and requirements

• Sample decomposition by fusion with sodium tetraborate (to convert silicate to a measurable form).
• Treatment of the fused residue with dilute nitric acid.
• Formation of molybdatosilicate by addition of ammonium molybdate.
• Reduction of the molybdatosilicate to molybdenum blue using ascorbic acid (or specified reducing agent).
• Spectrophotometric measurement of the molybdenum blue absorbance (approximately 600 nm) and calibration to determine Si content within the stated range.
• Applicability and interference notes (method particularly noted for use with fluorine-containing ores); references to sample-preparation and laboratory-water standards where relevant.

Typical use and users

Used by analytical laboratories in mining, mineral processing and steelmaking supply chains for routine and quality-control determination of silicon in iron ores and concentrates. Typical users include laboratory chemists, QA/QC engineers at mining companies, standards bodies adopting the method nationally, and contract testing laboratories.

Related standards

Part of the ISO 2598 series (ISO 2598-1:1992 covers gravimetric methods for silicon determination). Related iron-ores analytical standards include ISO 2597 (total iron determination) and other ISO standards on sampling/preparation (e.g., sample preparation and laboratory water quality standards referenced in national adoptions). Several national standards bodies have adopted or published equivalents (for example TCVN 8013-2:2009 referencing ISO 2598-2:1992).

Keywords

iron ores; silicon determination; molybdosilicate; reduced molybdosilicate; spectrophotometric method; molybdenum blue; sodium tetraborate fusion; analytical chemistry; QA/QC.

FAQ

Q: What is this standard?

A: ISO 2598-2:1992 is an international standard that specifies a reduced molybdosilicate spectrophotometric method for determining silicon content in iron ores and related materials.

Q: What does it cover?

A: It covers sample decomposition, reagent treatment, reduction to molybdenum blue and spectrophotometric measurement for silicon in the range ~0.10 % to 5.0 % by mass, applicable to natural ores, concentrates and agglomerates (including sinter), with guidance on interferences.

Q: Who typically uses it?

A: Analytical and QA/QC laboratories in mining and mineral processing, steel industry laboratories, standards bodies and contract testing services that need a standardized chemical method for silicon in iron ores.

Q: Is it current or superseded?

A: The original publication date is December 1992 (Edition 1). The ISO record indicates the publication has been reviewed and confirmed in subsequent systematic reviews and remains the published version; national adoptions and confirmations are recorded (check your national standards body for the most current national status or amendment information).

Q: Is it part of a series?

A: Yes — ISO 2598 is a multipart standard. Part 1 (ISO 2598-1:1992) covers gravimetric methods for silicon; Part 2 is the reduced molybdosilicate spectrophotometric method described here.

Q: What are the key keywords?

A: Iron ores, silicon, molybdosilicate, molybdenum blue, spectrophotometry, sodium tetraborate fusion, analytical method, ore concentrates.