Overview
ISO 8007-1:1999 specifies procedures for sampling consignments of cathode blocks used in the production of aluminium and for taking test samples from individual blocks. It complements the statistical sampling basis given in ISO 5022 and references ISO 6206 for sampling vocabulary. The standard focuses on practical, safe and traceable methods to obtain representative test specimens without compromising the structural integrity or serviceability of cathode blocks.
Key Topics
- Scope and references: Applies to sampling of cathode blocks; normative references include ISO 5022:1979 and ISO 6206:1979.
- Apparatus: Use suitable core-drilling equipment; cutting edges should preferably be coated with diamond or another extremely hard material.
- Sampling procedure: Test samples shall be taken by core drilling or sawing in accordance with ISO 5022 and the additional requirements of ISO 8007-1.
- Collector-bar slot distinction: Blocks produced with a collector-bar slot are treated differently from blocks produced without a slot when deciding sample locations.
- Extra-length blocks: Where consignments include blocks longer than final required length, sampling from the extra-length portion is preferred because drilled areas will be machined away.
- Sample dimensions:
- The smallest sample dimension (usually diameter) must be at least three times the maximum particle size of the dry aggregate.
- Where not specified by a test standard, a diameter of 30 mm or 50 mm is recommended, with length at least 1.5 times the diameter.
- Cross-sections should be circular; diameter must allow preparation of parallel-sided test pieces if required.
- Sampling report: The standard defines required report items (producer/customer, batch references, date/place, sampling plan, extra-length proportion, sketch of sampling points, sample dimensions, and sampler details).
Applications
ISO 8007-1:1999 is used by producers, buyers and testing laboratories involved in aluminium electrolysis to:
- Establish agreed sampling locations and plans for acceptance testing of cathode blocks.
- Ensure extraction of representative test specimens while avoiding weakening or contaminating blocks.
- Document sampling activities for traceability and contractual compliance.
Practical tips:
- Agree sampling locations between seller and buyer before sampling.
- Prefer sampling from extra-length material when available to avoid damaging the portion that will remain in service.
- Exercise extreme care for vertically drilled samples to prevent structural weakening.
Related Standards
- ISO 5022:1979 - Shaped refractory products - Sampling and acceptance testing (statistical basis).
- ISO 6206:1979 - Chemical products for industrial use - Sampling - Vocabulary.
- ISO 8007-2 - Part 2: Prebaked anodes (companion document).
- ISO 8007 Part 3 (in preparation) - Procedures for sampling sidewall blocks.
This guidance helps ensure that sampling for quality, mechanical and chemical testing of cathode blocks is consistent, safe and contractually verifiable.
Open preview (PDF)Carbonaceous materials used in the production of aluminium — Sampling plans and sampling from individual units — Part 1: Cathode blocks
