Overview
ISO 6629:1981 provides general instructions for the chemical analysis of chromium ores and concentrates, ensuring consistent and reliable testing methodologies. Developed by ISO Technical Committee ISO/TC 65, this standard outlines essential guidelines related to reagents, apparatus, sample preparation, analytical procedures, calibration graphs, and test reporting. It serves as a foundational reference for laboratories performing elemental analysis of chromium-bearing minerals and concentrates.
Key Topics
- Reagents: Specifies the use of recognized analytical grade reagents and mandates the use of distilled or deionized water for reagent preparation and trace element determinations.
- Apparatus: Details requirements for weighing devices (analytical balances with precision to 0.0002 g), laboratory equipment calibration, and the use of appropriate cells for absorbance measurements.
- Sample Preparation: Analysis should be conducted on air-dried or oven-dried samples (105–110 °C) to ensure moisture content consistency.
- Analytical Procedure: Emphasizes duplicate analysis of test samples for accurate element content determination. Includes protocols for blank tests and check tests using standard samples to validate results.
- Calibration Graphs: Calibration involves plotting element mass against measured values (e.g., absorbance), with graphs verified by standard solutions and checked with certified reference materials.
- Moisture Content: Hygroscopic moisture content must be measured in parallel, following ISO 6129, to convert results to a dry basis accurately.
- Test Reporting: Requires detailed documentation including sample identification, results with units, method references, and any deviations or optional operations affecting test outcomes.
Applications
ISO 6629:1981 is essential for laboratories and quality control units involved in:
- Mining and mineral processing: Ensuring accurate chemical characterization of chromium ores and concentrates.
- Metallurgy: Informing decisions on ore beneficiation and smelting processes based on reliable chemical data.
- Chemical industry: Providing accurate analysis results vital for manufacturing chromium-based products.
- Environmental testing: Assessing the composition of chromium minerals for compliance and impact analysis.
- International trade: Offering standardized testing procedures that support the consistent grading and valuation of chromium ores and concentrates across global markets.
Related Standards
- ISO 6129 - Chromium ores: Determination of hygroscopic moisture content in analytical samples (Gravimetric method). Integral for moisture content correction in chemical analysis results.
- Other pending ISO standards focus on sampling and sample preparation for chromium ores to complement the analytical procedures described in ISO 6629.
- General chemical analysis standards regarding apparatus calibration, reagent preparation, and quality control methods used in mineral analysis labs.
Keywords: ISO 6629, chromium ores analysis, chemical analysis methods, chromium concentrates, hygroscopic moisture, calibration graphs, analytical balance, chemical reagents, test reporting, mineral testing standards
Open preview (PDF)Chromium ores and concentrates — Methods of chemical analysis — General instructions
