Overview
ISO 22928-1:2024 - Rare earth - Analysis by wavelength dispersive X‑ray fluorescence spectrometry (WD‑XRFS) - Part 1 specifies a practical protocol for using semi‑quantitative standardless WD‑XRF commercial packages to assess rare earth element (REE) concentrations in rare earth magnet scrap recovered from end‑of‑life (EOL) products for recycling. The standard covers safe handling, dismantling, demagnetization, sample preparation, instrument setup, measurement conditions and reporting requirements for standardless XRF analysis of magnet scrap.
Key topics and requirements
- Scope and approach: Uses standardless wavelength dispersive XRF (WD‑XRFS) commercial software packages for semi‑quantitative analysis of REEs in magnet scrap intended for recycling.
- Handling and preparation: Procedures for dismantling EOL components, cleaning, demagnetization (heat treatment or alternating fields), and sample forms (bulk and powders).
- Apparatus and reagents: Lists required equipment such as WD‑XRFS instrument, furnace (up to 500 °C), demagnetizer, pulverizer/grinder, hydraulic press (300 MPa), vacuum desiccator, and analytical‑grade reagents (e.g., acetone, ethanol, alkaline cleaners).
- Analytes and concentration ranges: Standardless XRF should analyse elements from Na to U; reported results are limited to elements > 1% mass fraction (10 g/kg). Example ranges for Nd‑Fe‑B magnet scrap include:
- Major: Fe 1–70%, Nd 1–40%
- Minor REEs/elements (Pr, Dy, Tb, Gd, Ce, Ho, Ga, Co, Ni, Cu, Nb, Al, Zn): 1–10%
- Instrument setup and measurement: Guidance on measurement conditions, use of commercial standardless packages, and expression/reporting of semi‑quantitative results.
- Reporting and traceability: Required metadata with results (supplier, product, gross mass, physical form, storage, production date, magnet type, recommended dismantling procedure).
Applications and users
ISO 22928-1:2024 is practical for:
- Recycling facilities and recyclers assessing the REE content of magnet scrap for material recovery planning and sorting.
- Analytical laboratories implementing WD‑XRFS standardless workflows for bulk screening of Nd‑Fe‑B and Sm‑Co magnet scrap.
- Manufacturers and EOL processors needing compositional data to support circular‑economy strategies.
- Policy makers, waste managers and supply‑chain stakeholders monitoring secondary REE resources and supporting recycling targets.
Benefits include faster, non‑destructive screening of magnet scrap, standardized reporting thresholds (≥1% mass fraction), and guidance to improve REE recovery efficiency.
Related standards
- ISO 22444‑2 (Rare earth - Vocabulary - Metals and alloys)
- ISO 22450 (Recycling of rare earth elements - Information requirements)
- ISO/TS 22451 (Methods for measurement of REEs in industrial waste and EOL products)
Note: The document includes safety warnings; users must follow established laboratory safety and regulatory requirements when handling magnet scrap and hazardous reagents.