Overview
ISO 10237:1997 is an international standard that specifies a precise method for determining the residual-hydrogen content in calcined coke used in the production of aluminium. Calcined coke, a carbonaceous material, is essential in manufacturing anodes for aluminium electrolytic production. The standard focuses on a gravimetric combustion analysis technique that accurately measures hydrogen content in calcined coke, ensuring quality control in the aluminium industry. The method applies specifically to calcined coke products with a residual hydrogen content of less than 1% by mass.
Key Topics
- Material Focus: Carbonaceous materials, specifically calcined coke used in aluminium production.
- Scope of Analysis: Determination of residual hydrogen content in calcined coke.
- Sample Preparation: Crushing to grain size under 1 mm and drying at 220 °C.
- Measurement Principle: Complete combustion of the sample at 750 °C in an oxygen stream. Gases pass over copper oxide and lead(II) chromate, generating water that is absorbed and weighed.
- Hydrogen Quantification: The residual hydrogen content is calculated from the increase in mass of the drying agent used to absorb the combustion water.
- Precision: Repeatability of results within 0.005% absolute difference and reproducibility within 0.01% absolute, ensuring reliability across laboratories.
- Apparatus Details: Includes combustion furnace, gas washing bottles, oxygen flowmeters, absorption units with sulfuric acid or magnesium perchlorate, and a balance with 0.1 mg accuracy.
- Sampling Compliance: Sampling must adhere to ISO 6375 which deals with coke for electrodes.
Applications
- Quality Control in Aluminium Manufacturing: Ensures calcined coke meets required standards of residual hydrogen to optimize anode performance.
- Material Specification Validation: Confirms degree of calcination of green coke, critical for proper electrode function.
- Process Optimization: Helps metallurgical plants monitor and adjust calcination processes for improved coke quality.
- Research and Development: Supports labs analyzing carbonaceous materials for improved aluminium production technologies.
- Compliance and Certification: Enables aluminium industry suppliers to demonstrate adherence to international standards for carbonaceous material properties.
Related Standards
- ISO 6375:1980 – Carbonaceous materials for aluminium production – Sampling of coke for electrodes.
- ISO 4793:1980 – Laboratory sintered filters – Porosity grading, classification, and designation (used for gas washing bottle filtration).
- ISO 5725 – Precision of test methods – Provides guidelines on repeatability and reproducibility essential to validate the method’s reliability.
Summary
ISO 10237:1997 provides a detailed, standardized method for assessing the residual hydrogen content in calcined coke, a key material in aluminium anode production. By following this standard, aluminium producers and laboratories achieve accurate and reproducible hydrogen measurements, ensuring consistent carbonaceous material quality. This directly impacts the efficiency and longevity of aluminium electrolytic cells, supporting enhanced production outcomes. For organizations involved in extractive metallurgy and aluminium manufacturing, adherence to ISO 10237 is critical for maintaining material performance and meeting global quality requirements.