ISO 24544:2024
(Main)Rare earth — Recyclable Neodymium iron boron (NdFeB) resources — Classification, general requirements and acceptance conditions
Rare earth — Recyclable Neodymium iron boron (NdFeB) resources — Classification, general requirements and acceptance conditions
This document specifies the classification, general requirements and acceptance conditions for recyclable neodymium iron boron (NdFeB) resources. This document is applicable to recyclable NdFeB resources from end-of-life (EOL) products and manufacture processes.
Terres rares — Ressources en néodyme-fer-bore (NdFeB) recyclable — Classification, exigences générales et conditions de recette
General Information
Standards Content (Sample)
International
Standard
ISO 24544
First edition
Rare earth — Recyclable
2024-02
Neodymium iron boron (NdFeB)
resources — Classification, general
requirements and acceptance
conditions
Terres rares — Ressources en néodyme-fer-bore (NdFeB)
recyclable — Classification, exigences générales et conditions de
recette
Reference number
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification and codes . 3
4.1 General .3
4.2 Classification of recyclable S-NdFeB resources .3
4.2.1 Recyclable S-NdFeB resources from EOL products .3
4.2.2 Recyclable S-NdFeB resources from industrial products .4
4.3 Classification of recyclable B-NdFeB resources .5
4.4 Classification of recyclable D-NdFeB resources .5
4.5 Codes of recyclable NdFeB resources .5
5 General requirements . 7
5.1 Sampling .7
5.1.1 General .7
5.1.2 Recyclable S-NdFeB resources from EOL products .7
5.1.3 Recyclable S-NdFeB resources from industrial products .7
5.2 Testing and analysis .7
5.3 Packaging .8
5.4 Transportation and storage .8
5.5 Labelling .8
6 Acceptance conditions . 8
Bibliography .10
iii
Foreword
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bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
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This document was prepared by Technical Committee ISO/TC 298, Rare earth.
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iv
Introduction
Rare earth elements (REEs) are an important ingredient in products such as magnets, luminous devices and
catalysts. Among these, magnets, especially neodymium iron boron (Nd Fe B or NdFeB in shortened form),
2 14
consume more than a mass fraction of 30 % of rare earths. The process of exploring and producing rare
earths is causing pressure on the environment due to the use of different kinds of chemical agents as well as
the resulting emissions of waste water, slag, dust and gas. In addition, there are limited primary rare earth
resources available for economically viable production across the world. The recovery of rare earth from
industrial products (including scraps and sludge) and end-of-life (EOL) products will help address these
problems, particularly from a long-term perspective.
The NdFeB magnet is the permanent magnet of choice in many products, including in the motors of electronic
vehicles and hard discs in computers, and is a key component of air conditioners. The use of both sintered
and bonded NdFeB products has grown steadily during the last several decades at an average annual growth
[1]
rate of around 9 % and 6,2 %, respectively. The steady growth of NdFeB production has led to an increase
in recyclable resources, especially sintered NdFeB scrap. These recyclable NdFeB resources contain not only
about 30 % of REEs, but also other valuable elements such as Co, Ni, Ga, etc., which shows there is significant
potential in recycling these resources to effectively supplement rare earth resources.
In addition, when the products containing NdFeB magnets come to the end of their lives, there will be an
increase in EOL products. Therefore, recycling rare earth from recyclable NdFeB resources can meet a
substantial part of the demand for global light (Nd and Pr) REEs and heavy (Dy and Tb) REEs.
However, a challenge for recycling rare earth is that the recyclable NdFeB resources from different sources
and processes can vary significantly in form, shape, chemical composition, phase structure, etc., leading to
quite complex and diverse recycling methods. Figure 1 provides an example of sintered NdFeB (S-NdFeB),
[2]
which accounts for about 90 % of the total market, to illustrate some of the typical recyclable resources
from EOL products and industrial processes, and the recycled products that can be created using a highly
efficient and low polluting recovery method as follows:
— For some large sintered NdFeB magnets from EOL products, after removing the coating, the cleaned
magnet can be used as raw materials and can be further manufactured into sintered NdFeB magnets.
— NdFeB sludge from industrial products in the machining stage is usually recycled into NdFeB powders
or magnets by using a combination of calcium thermal reduction and sintering, or into REE compounds
by using hydrometallurgy or thermometallurgy, depending on the oxidation and main phase structure
of the sludge.
— Scraps including unqualified bulk, residual powder and other recyclable resources from different
processing stages can be applied in different steps of the sintering process and regenerated into recycled
NdFeB magnets according to the phase, and the degree of contamination and oxidation.
v
Figure 1 — Typical examples of recyclable NdFeB resources from different sources, and possible
methods to recycle to different products
Therefore, it is important to determine the characteristics of different recyclable NdFeB resources. This
document provides the classification, general requirements and acceptance conditions for recyclable NdFeB
resources, considering the unique characteristics of the different resources and the industrial recycling
methods that can be used.
This document promotes the efficient recycling of valuable REE elements across countries that produce and
consume magnets.
vi
International Standard ISO 24544:2024(en)
Rare earth — Recyclable Neodymium iron boron (NdFeB)
resources — Classification, general requirements and
acceptance conditions
1 Scope
This document specifies the classification, general requirements and acceptance conditions for recyclable
neodymium iron boron (NdFeB) resources.
This document is applicable to recyclable NdFeB resources from end-of-life (EOL) products and manufacture
processes.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 22450:2020, Recycling of rare earth elements — Requirements for providing information on industrial
waste and end-of-life products
ISO/TS 22451, Recycling of rare earth elements — Methods for the measurement of rare earth elements in
industrial waste and end-of-life products
ISO 22453, Exchange of information on rare earth elements in industrial wastes and end-of-life cycled products
ISO 22928-1, Rare earth — Analysis by wavelength dispersive X-ray fluorescence spectrometry (WD-XRFS) —
Part 1: Determination of composition of rare earth magnet scraps using standardless XRF commercial packages
IEC 60404-1, Magnetic materials — Part 1: Classification
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
rare earth element
REE
collective name for scandium (Sc), yttrium (Y) and the lanthanides (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho,
Er, Tm, Yb, Lu), which was approved by the International Union for Pure and Applied Chemistry (IUPAC) in
[1]
its 2005 Nomenclature of Inorganic Chemistry Recommendations
Note 1 to entry: Certain terms and corresponding abbreviated terms are common such as rare earth element (REE or
RE) and rare earth oxide (REO).
Note 2 to entry: Rare earth elements are frequently referred to as being either light rare earth (LREE), medium rare
earth (MREE) or heavy rare earth (HREE), with LREE including the elements between lanthanum (La) and neodymium
(Nd), MREE including the elements between samarium (Sm) and gadolinium (Gd), and HREE including the elements
from terbium (Tb) to lutetium (Lu) as well as scandium (Sc) and yttrium (Y).
Note 3 to entry: Didymium is commonly used to express a mixture of the elements Pr and Nd.
Note 4 to entry: Characteristics of rare earth elements are described in ISO 22444-1:2020, Annex A.
[SOURCE: ISO 22444-1:2020, 3.1]
3.2
neodymium iron boron
NdFeB
kind of permanent magnet made from an alloy of neodymium, iron, and boron to form the
Nd Fe B tetragonal crystalline structure
2 14
3.3
sintered neodymium iron boron
S-NdFeB
NdFeB (3.2) magnet prepared by a powder metallurgy method
Note 1 to entry: In the powder metallurgy method, the raw materials are melted and casted into flake-like ingots with
strip-casting technique; the ingots are pulverized with hydrogen decrepitation technique and then milled into single-
crystal powders with jet-milling technique; the powders are aligned in magnetic field and pressed into green compacts
and then sintered into dense blocks; the blocks are heat-treated, cut to shape, surface treated and magnetized.
Note 2 to entry: Sintered NdFeB magnets are the most widely used rare earth magnet and contribute to about 92 %
market supply of all NdFeB magnets. They have the strongest energy density of all kinds of permanent magnets.
3.4
bonded neodymium iron boron
B-NdFeB
NdFeB (3.2) magnet prepared by mixing NdFeB powders and binders such as organic or inorganic adhesives,
and then compressed or injected into dense blocks, surface treated and magnetized
Note 1 to entry: Bonded NdFeB magnets contribute to 6 % to 7 % of the market supply of all NdFeB magnets. They
usually exhibit lower magnetic properties than S-NdFeB (3.3) magnets but can be prepared directly into a net shape or
near net shape with complex shapes.
3.5
deformed neodymium iron boron
D-NdFeB
NdFeB (3.2) magnet prepared with hot pressing and hot deformation of nanocrystalline NdFeB ribbons
Note 1 to entry: Deformed NdFeB magnets contribute to about 1 % to 2 % of the market supply of all NdFeB magnets.
They have a similar energy density to S-NdFeB (3.3) magnets and are usually prepared into ring-shape magnets with
strong magnetic anisotropy.
3.6
recyclable neodymium iron boron resource
recyclable NdFeB resource
resource usually collected from end-of-life (EOL) and manufacture processed S-NdFeB, B-NdFeB, and
D-NdFeB magnet component
...
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