ISO 2926:2013

Overview - ISO 2926:2013 (aluminium oxide particle size analysis)

ISO 2926:2013 specifies a dry sieve method using electroformed sieves to determine the mass distribution of particle sizes in calcined aluminium oxide (alumina) used for the production of primary aluminium. The method covers the particle size range 45 µm to 150 µm, and is intended for samples containing up to 20% by mass >150 µm and up to 15% by mass <45 µm. The procedure uses a mechanical sieve shaker, electroformed test sieves (150, 106, 75, 53, 45 µm), and laboratory weighing to produce cumulative mass‑percent retained results.

Key topics and technical requirements

• Sieve type: Smooth electroformed sheets with square openings (woven wire sieves are not applicable). Aperture tolerances per ISO 3310-3.
• Nominal sieve sizes: 150 µm, 106 µm, 75 µm, 53 µm, 45 µm.
• Sample mass: Final test portion weighed to 0.01 g, nominally 45–55 g (50 g recommended).
• Apparatus: Mechanical sieve shaker imparting combined horizontal rotary motion and vertical tapping; top‑pan balance (0.01 g); fine soft brush for sieve cleaning.
• Procedure: Clean and inspect sieves, assemble stack (largest aperture at top), sieve for 30 minutes, weigh retained fractions and bottom receiver, calculate cumulative mass percent.
• Effective aperture (EA): EA determination using certified reference materials (e.g., NIST CRMs like 1004a/1004b, 1017b) is recommended. Tolerance guidance: ±2 µm for 45 µm sieves, ±5 µm for 53–150 µm sieves.
• Quality metrics: Precision data (repeatability r and reproducibility R) provided from interlaboratory studies; results are sample dependent.
• Cleaning & inspection: Brushing and visual/microscope inspection for blinding or ruptures; repairs permitted if verified.

Practical applications

• Incoming quality control of calcined alumina for smelters - verify particle size distribution to meet process and material specifications.
• Process control and optimisation in primary aluminium production - particle size affects dissolution and smelting behaviour.
• Supplier qualification and material acceptance - objective test method for contracts and specifications.
• Laboratory benchmarking and interlaboratory studies - use of EA and NIST CRMs supports comparability across labs.

Who should use ISO 2926:2013

• Aluminium refinery quality laboratories and production engineers
• Material suppliers and procurement teams specifying calcined alumina
• Third‑party testing labs and accreditation bodies
• R&D teams studying feedstock granulometry and process effects

Related standards and references

• ISO 3310‑3 (test sieves - electroformed sheets) - normative reference.
• ISO/TC 226 (committee responsible for materials for primary aluminium).
• Method origins: based on AS 2879.6‑1995; interlaboratory programme referenced AS 2850.

Keywords: ISO 2926:2013, particle size analysis, aluminium oxide, electroformed sieves, 45 µm to 150 µm, calcined alumina, effective aperture, sieve method.