Overview
ISO 7764:2006 is an internationally recognized standard developed by ISO that specifies the method for preparing predried test samples of natural iron ores and their concentrates for chemical analysis. This preparation is essential for determining the analytical values of ore constituents on a dry basis, ensuring precise and reproducible chemical composition results. The standard applies specifically to natural iron ores, iron ore concentrates, and agglomerated products such as sinter but excludes certain ore types, including those with high sulfur content, combined water content above defined limits, or containing metallic iron.
Key Topics
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Scope and Applicability
The method defined in ISO 7764:2006 is targeted at the preparation of test samples for chemical analysis but excludes:
- Processed ores containing metallic iron (direct-reduced iron)
- Ores with sulfur content above 0.2% by mass
- Ores having combined water content greater than 2.5% by mass
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Sample Preparation Process
- Drying test samples at a controlled temperature of 105 °C ± 2 °C until constant mass is achieved
- Employing laboratory equipment such as precision balances (minimum readability 0.0001 g), drying ovens, and appropriate weighing bottles (glass or heat-resistant plastic)
- Cooling samples in desiccators with self-indicating silica gel to prevent moisture absorption during weighing
- Using laboratory samples prepared with particle sizes less than 100 µm in accordance with ISO 3082
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Quality Control Measures
Ensuring the sample is representative and homogeneous through thorough mixing and multiple incremental sampling
Accurate mass determination by comparing weights before and after drying
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Normative References
ISO 7764 refers to complementary standards such as ISO 3082 for sampling and sample preparation and ISO 2596 for hygroscopic moisture determination when applicable.
Applications
ISO 7764:2006 is essential for laboratories and industries involved in iron ore quality assessment, mining operations, and processing plants where accurate chemical analysis of iron ores impacts:
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Quality Assurance in Iron Ore Processing
Reliable determination of dry-basis constituent values enables better control over beneficiation and sintering processes.
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Trade and Contract Compliance
Preparation of standardized test samples supports contractual obligations by ensuring consistent and reproducible chemical assay results.
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Research and Development
Accurate and standardized sample drying methodologies facilitate research on ore characteristics and metallurgical behaviors.
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Environmental and Regulatory Reporting
Analytical results derived from properly prepared samples help meet environmental monitoring and reporting requirements.
Related Standards
- ISO 3082:2000 – Iron ores: Sampling and sample preparation procedures for correct laboratory sample representation.
- ISO 2596:1994 – Iron ores: Determination of hygroscopic moisture in analytical samples by gravimetric and Karl Fischer methods. Used when ISO 7764 is not applicable due to moisture constraints.
- Other iron ore relevant ISO standards related to chemical analysis and sample preparation to ensure a comprehensive approach to ore assessment.
Keywords: ISO 7764, iron ores, sample preparation, predried test samples, chemical analysis, iron ore concentrates, sinter products, drying method, laboratory sample, iron ore standard, ISO iron ore standards, ore chemical testing, analytical sample drying, iron ore quality control.
