ISO 13909-6:2016

Overview

ISO 13909-6:2016 - "Hard coal and coke - Mechanical sampling - Part 6: Coke - Preparation of test samples" specifies procedures for preparing coke test samples from primary increments through to ready-to-test samples. The standard covers the constitution, reduction, division, mixing, drying and storage of coke samples, and provides guidance on achieving required precision for analytical tests (for example total moisture, general analysis and physical tests). It is part of the ISO 13909 series on mechanical sampling of hard coal and coke.

Key topics and technical requirements

• Scope and purpose: Defines how to prepare representative test samples of coke from combined primary increments or from individual increments when required.
• Sample constitution: Primary increments shall be combined in proportion to flow rate; samples can be constituted directly or after fixed-ratio division.
• Reduction and division methods: Describes mechanical and manual division methods, including falling-stream dividers and manual techniques such as riffle, flattened‑heap and strip‑mixing-and-splitting methods.
• Preparation for specific tests: Guidance for preparing samples for total moisture determination, general chemical analysis, physical testing and special property tests; includes requirements for wet samples, reserve samples and sample reduction.
• Precision and variance: References ISO 13909-7 for precision formulae and gives target preparation/testing variance levels (procedures are designed to achieve a preparation/testing variance V of 0.05 or less for moisture tests).
• Equipment design: Requirements and recommendations for dividers, cutters, crushers and complete preparation systems, including checks for precision and bias and for normal/abnormal operation.
• Storage and traceability: Guidance on storage of test samples and maintaining representative material for reserve testing.

Practical applications and users

This standard is intended for:

• Quality control and assurance personnel at coke producers and metallurgical plants (steelworks).
• Laboratories performing chemical and physical testing of coke (moisture, reactivity, strength indices).
• Inspectors and auditors responsible for verifying sampling and sample preparation procedures.
• Designers and operators of mechanical sampling and preparation systems. Practical benefits include improved representativity of test samples, reduced preparation bias, and reproducible results across moisture, size distribution, strength and other coke tests.

Related standards

• ISO 13909 series (Parts 1–8) - mechanical sampling of hard coal and coke
• ISO 13909-5 - Coke - Sampling from moving streams
• ISO 13909-7 - Methods for determining precision of sampling, sample preparation and testing
• ISO 13909-8 - Methods of testing for bias
• ISO 579, ISO 687 - Methods for moisture determination and general analysis

Keywords: ISO 13909-6:2016, coke sample preparation, mechanical sampling, coke test samples, primary increments, sample division, total moisture, preparation precision, sampling equipment.