Overview
ISO 12984:2018 specifies a standardized method for determining the particle size distribution of calcined coke used in the production of aluminium. This testing method is essential for quality control in aluminium manufacturing, ensuring consistent properties in raw materials. The method outlined in ISO 12984:2018 is also applicable to consignments of calcined anthracite, but does not apply to carbonaceous material processed by sieving, crushing, or filter fines. The particle size analysis covers sizes between 0.25 mm and 16 mm, providing a reliable overview of typical coke size distributions as produced by the calcination of delayed petroleum coke.
By following ISO 12984:2018, laboratories and producers can assess materials with confidence, allowing both suppliers and customers to verify that coke used for aluminium production meets agreed particle size specifications. This contributes to improved process control and end-product quality in the aluminium industry.
Key Topics
- Sample Scope: The standard applies to samples of calcined coke and calcined anthracite with a typical size distribution from the calcination process.
- Particle Size Range: The method is valid for particle sizes between 0.25 mm and 16 mm, with size fractions outside this range not comprising more than 10% of the total.
- Testing Principle: Analysis is performed by dry sieve testing, using a series of specified metal wire cloth sieves.
- Apparatus Requirements: Sieves conforming to ISO 565 and ISO 3310-1, batch-type sieve shaker, precision balances, and drying equipment.
- Sampling and Preparation: Samples must be representative and carefully prepared to avoid altering particle size, based on guidelines in ISO 6375.
- Result Expression: Outcome is reported as the percentage by mass retained on each sieve, and cumulative percentages for each size increment.
- Precision: Repeatability is defined for cumulative percentages, particularly between 20% and 80% of the sample.
Applications
ISO 12984:2018 plays a crucial role in several industry applications:
- Quality Assurance in Aluminium Production: Ensures calcined coke meets stringent specifications for use as a carbon material in the manufacture of aluminium.
- Supplier-Customer Agreements: Provides a common, objective standard for verifying coke shipments, reducing disputes over particle size compliance.
- Laboratory Testing Protocols: Supports laboratories in establishing validated, consistent procedures for particle size distribution analysis.
- Specification Development: Allows producers and users to establish mutually agreed benchmarks for “as dispatched” and “as received” materials, enhancing supply chain transparency.
The approach outlined in ISO 12984:2018 improves product consistency and enables better process control in primary aluminium production. Reliable particle size analysis helps optimize electrode performance and prolongs equipment lifespan in electrolysis cells.
Related Standards
For comprehensive material testing and quality assurance in the production of aluminium and other industries, the following related ISO standards are often referenced alongside ISO 12984:2018:
- ISO 565: Test sieves – Metal wire cloth, perforated metal plate and electroformed sheet – Nominal sizes of openings
- ISO 3310-1: Test sieves – Technical requirements and testing – Part 1: Test sieves of metal wire cloth
- ISO 6375: Carbonaceous materials for the production of aluminium – Coke for electrodes – Sampling
These standards together provide a robust framework for the sampling, testing, and specification of carbonaceous materials, supporting quality and efficiency in aluminium manufacturing and other sectors using calcined coke.
Implementing ISO 12984:2018 ensures that particle size analysis of calcined carbon materials is performed accurately, consistently, and in alignment with global best practices.