ISO 9685:1991

Overview

ISO 9685:1991 establishes a standardized method for determining the nickel and/or chromium content in iron ores using flame atomic absorption spectrometry (FAAS). Issued by the International Organization for Standardization (ISO), this method is applicable for nickel and chromium concentrations ranging from 0.003% to 0.1% (mass/mass) in natural iron ores, iron ore concentrates, and agglomerates, including sinter products.

By providing clear procedures for sample preparation, reagent usage, instrumental setup, and calculation, ISO 9685:1991 ensures accurate, consistent, and repeatable results across laboratories and industries dealing with iron ore analysis.

Keywords: ISO 9685:1991, iron ore analysis, nickel determination, chromium determination, atomic absorption spectrometry, FAAS, standard method, metallurgical testing

Key Topics

• Scope: Applies to various iron ore materials, including natural ores, concentrates, and sintered products with nickel/chromium contents between 0.003% - 0.1% (m/m).
• Sample Preparation: Outlines requirements for laboratory samples, including recommended particle sizes and predrying methods.
• Analytical Procedure: Details the sequential chemical treatments, including acid digestion, removal of iron, fusion of residue, and preparation for spectrometric analysis.
• Flame Atomic Absorption Spectrometry: Specifies use of air-acetylene and dinitrogen oxide-acetylene burners and describes operating conditions for optimal sensitivity and linearity.
• Accuracy and Precision: Provides guidelines for running duplicate analyses, blank and reference tests, and criteria for repeatability and permissible tolerance.
• Results Calculation and Reporting: Defines calculation formulas for nickel and chromium content and standardizes the format for reporting analytical results.

Applications

Industry and Laboratories

• Iron and Steel Manufacturing: Essential for controlling the quality of iron ore feedstocks, particularly where trace nickel or chromium can affect steel properties.
• Mining and Mineral Processing: Applied during exploration, beneficiation, and processing to determine the compositional quality of iron ores.
• Analytical Laboratories: Used by laboratory professionals for routine chemical analysis of iron ore samples following a harmonized, internationally recognized procedure.

Quality Assurance and Compliance

• Comparability: Enables reliable comparison of results between different labs and production sites by adhering to a common analytical standard.
• Product Certification: Provides data necessary for product specification, contractual requirements, and conformity assessment in the global ore trade.
• Environmental Monitoring: Facilitates monitoring of trace metals in ores, supporting compliance with environmental and safety regulations.

Related Standards

For a comprehensive approach to iron ore sampling, preparation, and analysis, ISO 9685:1991 references several related ISO standards:

• ISO 648:1977 – Laboratory glassware – One-mark pipettes
• ISO 1042:1983 – Laboratory glassware – One-mark volumetric flasks
• ISO 3081:1986 – Iron ores – Increment sampling – Manual method
• ISO 3082:1987 – Iron ores – Increment sampling and sample preparation – Mechanical method
• ISO 3083:1986 – Iron ores – Preparation of samples – Manual method
• ISO 7764:1985 – Iron ores – Preparation of predried test samples for chemical analysis

These related standards ensure standardization across all stages of sample management and chemical analysis, supporting traceability and quality in iron ore testing.

By following ISO 9685:1991 for nickel and chromium determination in iron ores, organizations enhance the validity of their chemical analysis, support global trade, and ensure compliance with industry expectations.