Overview
ISO 13909-6:2025 - "Coal and coke - Mechanical sampling - Part 6: Preparation of test samples of coke" provides standardized requirements and guidance for preparing coke test samples from primary increments through to samples ready for specific laboratory tests. This third edition aligns the ISO 13909 series for coke sampling and updates requirements on constitution, reduction, division, and equipment design to ensure representative, precise test samples for chemical and physical testing.
Key topics and technical requirements
- Scope and terminology: Defines terms consistent with ISO 13909-1 and sets the document’s boundary specifically for coke sample preparation.
- Precision of sample preparation: Uses the precision framework referenced in ISO 13909-7 to estimate preparation precision; procedures aim to achieve a preparation/testing variance (V_PT) of 0.05 or less for total moisture tests.
- Constitution of a sample: Rules for combining primary increments or prepared subsamples, including weighted combination of increments and handling of reserve samples.
- Division and reduction methods:
- Mechanical methods: Design and use of dividers (including falling‑stream dividers), cutters, mass/interval parameters for cuts, and crusher types.
- Manual methods: Riffle splitting, flattened‑heap, and strip‑mixing/splitting techniques for smaller or manual operations.
- Preparation for specific tests: Requirements for preparing samples for total moisture, general chemical analysis, physical testing (shatter index, Micum/Irsid indexes, reactivity, density, size distribution), and samples for special properties; includes guidance on segregation error control and reduction methods.
- Equipment design and operation: Criteria for dividers, cutter velocity, crushers, integrated preparation systems, normal/abnormal operation, and provisions for checking precision and testing bias.
- Storage and documentation: Handling of wet/dry test samples and retention of reserve samples.
Practical applications and users
ISO 13909-6:2025 is intended for:
- Industrial laboratories and quality control teams in coke production and metallurgical plants
- Sampling engineers and technicians responsible for mechanical sampling systems
- Third‑party testing laboratories conducting moisture, reactivity, strength and size‑distribution tests
- Standards bodies and auditors assessing sampling system performance and bias
Benefits include improved representativeness of test samples, reduced segregation and preparation error, and standardized procedures that support reliable test results and regulatory compliance.
Related standards
Keywords: ISO 13909-6:2025, coke sample preparation, mechanical sampling, test samples, sample division, moisture testing, sampling precision, dividers, crushers.