ISO 22444-2:2020

Rare earth — Vocabulary — Part 2: Metals and their alloys

This document defines the terms for rare earth metals and their alloys, as well as for methods of preparation and purification. This document can be used as a reference to unify technical terms in rare earth production, application, inspection, circulation, trading, scientific research and education.

Terres rares — Vocabulaire — Partie 2: Métaux et alliages

General Information

• Status: Published
• Publication Date: 14-Oct-2020
• ICS: 01.040.13 - Environment. Health protection. Safety (Vocabularies)
• ICS: 13.030.30 - Special wastes
• Technical Committee: ISO/TC 298 - Rare earth
• Drafting Committee: ISO/TC 298 - Rare earth
• Current Stage: 6060 - International Standard published
• Start Date: 15-Oct-2020
• Due Date: 24-Apr-2020
• Completion Date: 15-Oct-2020

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 22444-2
First edition
2020-10
Rare earth — Vocabulary —
Part 2:
Metals and their alloys
Terres rares — Vocabulaire —
Partie 2: Métaux et alliages
Reference number
ISO 22444-2:2020(E)
©
ISO 2020

---------------------- Page: 1 ----------------------
ISO 22444-2:2020(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 22444-2:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Terms related to rare earth metals . 3
5 Terms related to rare earth alloys . 3
6 Terms related to the preparation and purification process of rare earth metals and
their alloys . 6
Annex A (informative) Basic properties of individual rare earth metals .9
Bibliography .10
© ISO 2020 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 22444-2:2020(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 298, Rare earth.
A list of all parts in the ISO 22444 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 22444-2:2020(E)

Introduction
Rare earth metals and their alloys are key raw materials for developing high-performance rare earth
functional materials, such as hydrogen-storage materials, magnetic materials and superconducting
materials, and are widely used in fields such as sustainable energy, robotics and electronic information.
Rare earth metals are also important additive elements for aluminium-base, magnesium-base, copper-
base, titanium-base and other alloys.
This document specifies terms for use by producers, consumers and traders in the field of rare earth
metals and their alloys. This document will serve as a reference that will help to reduce discrepancies
or trade disputes caused by inconsistencies in terms used when dealing with rare earth metals and
their alloys.
© ISO 2020 – All rights reserved v

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 22444-2:2020(E)
Rare earth — Vocabulary —
Part 2:
Metals and their alloys
1 Scope
This document defines the terms for rare earth metals and their alloys, as well as for methods of
preparation and purification.
This document can be used as a reference to unify technical terms in rare earth production, application,
inspection, circulation, trading, scientific research and education.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
rare earth impurity
undesirable rare earth element present in a rare earth metal (4.1) or rare earth alloy (5.1) other than the
specified or target rare earth element(s)
3.2
non-rare earth impurity
undesirable non-rare earth element present in a rare earth metal (4.1) or rare earth alloy (5.1)
3.3
interstitial impurity
undesirable, non-metallic element such as hydrogen, boron, carbon, nitrogen or oxygen occupying
interstitial positions in the lattice of a rare earth metal (4.1) or rare earth alloy (5.1)
3.4
rare earth metal content
total rare earth metal content
mass fraction of rare earth elements in a rare earth metal (4.1) or rare earth alloy (5.1)
Note 1 to entry: It is generally provided as a percentage of the metal, i.e. % TREM.
© ISO 2020 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO 22444-2:2020(E)

3.5
average atomic mass of rare earths in mixed rare earth metals or alloys
M
ratio of the total mass of rare earth elements to their total number of moles, as shown by the formula:
N
m
m mm++…+m
∑
i
total i=1 12 N
M== =
n N m m m m
i 1 2 N
total
++…+
∑
i=1
M M M M
i 1 2 N
where
m is total mass of rare earth elements, in g;
total
n is total number of moles of rare earth elements, in moles;
total
m is mass of rare earth element i, i = 1, 2, …, N, in g;
i
M is atomic mass of rare earth element i, i = 1, 2, …, N, in g/mol.
i
Note 1 to entry: M is given in g/mol.
EXAMPLE 1 The average atomic mass of a mixed rare earth metal (4.4) containing 20 % mass of praseodymium
and 80 % of neodymium is calculated as follows:
m = 20 units, m = 80 units, M = 140,907 7 g/mol, M = 144,24 g/mol
Pr Nd Pr Nd
20+80
M= =143,56
20 80
+
140,,9077 144 24

EXAMPLE 2 The average atomic mass of rare earths in Tb-Dy-Fe (5.21) magnetostrictive materials, of which
the formula is Tb Dy Fe , is calculated as follows:
0,3 0,7 2
M = 158,9254 g/mol, M = 162,5 g/mol, M = 55,847 g/mol
Tb Dy Fe
m = M × 0,3 / (M × 0,3 + M × 0,7 + M × 2) × 100 = 17,46 units
Tb Tb Tb Dy Fe
m = M × 0,7 / (M × 0,3 + M × 0,7 + M × 2) × 100 = 41,65 units
Dy Dy Tb Dy Fe
17,,46+41 65
M= =161,43
17,46 41,65
+
158,9254 162,5

3.6
rare earth metal purity
absolute rare earth metal purity
mass fraction of a specified rare earth element in a metal
Note 1 to entry: It is expressed as a percentage.
3.7
relative rare earth metal purity
mass fraction of the specified rare earth element out of the rare earth metal content (3.4)
Note 1 to entry: It is expressed as a percentage, i.e. Nd/TREM.
2 © ISO 2020 – All rights reserved

---------------------- Page: 7 ----------------------
ISO 22444-2:2020(E)

4 Terms related to rare earth metals
4.1
rare earth metal
metallic substance containing one or more rare earth elements
4.2
individual rare earth metal
metallic substance containing only one rare earth element, including La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb,
Dy, Ho, Er, Tm, Yb, Lu, Sc and Y
Note 1 to entry: The basic information for each rare earth element is given in ISO 22444-1:2020, Table A.1. The
basic properties of rare earth metals (4.1) are given in Table A.1.
4.3
high purity rare earth metal
individual rare earth metal (4.2) with a minimum rare earth metal purity (3.6) of 99,9 %
Note 1 to entry: The main impurities to be controlled typically include rare earth impurities (3.1), Si, K, Na, Ca, Mg,
Al, Ti, Ni, Co, Mn, Cu, Fe, Pb, Zn, Sn, Cd, Ta, Nb, Cr, W, Mo, C, S, P, Cl, F, N and O.
4.4
mixed rare earth metal
metallic substance containing two or more rare earth elements
4.5
mischmetal
metallic substance mainly containing the rare earth elements Ce and La as major components, with
small amounts of Nd, Pr, etc., of which the compositional ratio of each REE is typically similar to that
found in the resource minerals
4.6
Pr-Nd metal
didymium
metallic substance containing the rare earth elements of Pr and Nd
Note 1 to entry: It is occasionally represented by the abbreviation Di.
Note 2 to entry: The content of Pr in Di is generally more than 18 %.
4.7
La-Ce metal
metallic substance containing the rare earth elements of La and Ce
5 Terms related to rare earth alloys
5.1
rare earth alloy
metallic substance containing one or more rare earth elements and one or more non-rare earth metal(s)
or semi-metal element(s)
Note 1 to entry: The alloys may be compounds, solid solutions, intermetallics or mixtures of the components.
5.2
rare earth master alloy
rare earth alloy (5.1) of selected rare earth element(s) that can be added to a charge of molten metal to
provide a desired composition or texture or to deoxidize the material
Note 1 to entry: The content of rare earth element(s) in rare earth master alloy is generally higher than that in
the rare earth modified alloy (5.10).
© ISO 2020 – All rights reserved 3

---------------------- Page: 8 ----------------------
ISO 2244
...

DRAFT INTERNATIONAL STANDARD
ISO/DIS 22444-2
ISO/TC 298 Secretariat: SAC
Voting begins on: Voting terminates on:
2019-11-11 2020-02-03
Rare earth — Terms and definitions —
Part 2:
Metals and their alloys
ICS: 01.040.13; 13.030.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
This document is circulated as received from the committee secretariat.
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 22444-2:2019(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2019

---------------------- Page: 1 ----------------------
ISO/DIS 22444-2:2019(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/DIS 22444-2:2019(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 General Terms and definitions . 1
3.1 Purity . 2
3.1.1 Rare earth metal purity . 2
3.1.2 Relative rare earth metal purity . 2
4 Rare earth metal . 3
4.1 Individual rare earth metal . 3
4.2 High purity rare earth metal . 3
4.3 Mixed rare earth metal . 3
4.3.1 Mischmetal . 3
4.3.2 Didymium/Pr-Nd metal . 3
4.3.3 La-Ce metal . 3
5 Rare earth alloy . 3
5.1 Rare earth master alloy . 3
5.1.1 Rare earth ferroalloy . 3
5.1.2 Rare earth ferrosilicon alloy . 3
5.1.3 Rare earth magnesium ferrosilicon alloy. 4
5.1.4 Rare earth aluminium alloy . 4
5.1.5 Rare earth magnesium alloy . 4
5.1.6 Rare earth copper alloy . 4
5.1.7 Rare earth nickel alloy . 4
5.2 Rare earth modified alloy . 4
5.2.1 Rare earth modified aluminium alloy . 4
5.2.2 Rare earth modified magnesium alloy . 4
5.2.3 Rare earth modified copper alloy . 4
5.2.4 Rare earth modified titanium alloy . 4
5.3 Rare earth intermetallic compound. 5
5.3.1 Nd-Fe-B . 5
5.3.2 Ce-Fe-B . 5
5.3.3 La-Ni . 5
5.3.4 Sm-Co . 5
5.3.5 Gd-Si-Ge . 5
5.3.6 Tb-Dy-Fe . 5
5.3.7 Sm-Fe-N . 5
5.3.8 La-Fe-Si . 5
6 Preparation and purification process of rare earth metals and their alloys .5
6.1 Thermal reduction process . 5
6.1.1 Metallothermic reduction . 5
6.1.2 Silicothermic reduction . . 6
6.1.3 Carbothermic reduction . 6
6.2 Reduction-distillation method . 6
6.3 Intermediate alloy method . 6
6.4 Molten salt electrolysis . 6
6.5 Reduction-diffusion method (R-D method) . 6
6.6 Co-reduction method . 6
6.7 Mixed smelting . 6
6.8 Vacuum refining . 7
6.9 Vacuum distillation/sublimation . 7
6.10 Electrorefining . . 7
© ISO 2019 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO/DIS 22444-2:2019(E)

6.11 Solid state electrotransport . 7
6.12 Zone refining . 7
6.13 Electron beam melting purification . 7
6.14 Levitation melting . 7
6.15 Fused-salt extraction method . 8
Annex A (informative) Basic properties of individual rare earth metals .9
iv © ISO 2019 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/DIS 22444-2:2019(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is the information given for the convenience of users and does
not constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment,
as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the
Technical Barriers to Trade (TBT) see the following URL: www .iso .org/iso/foreword .html.
The committee responsible for this document is Technical Committee [or Project Committee] ISO/TC
[or ISO/PC] 298, [rare earth], Subcommittee SC ##, [name of subcommittee].
This second/third/… edition cancels and replaces the first/second/… edition (ISO 2019#:2019), which
has been technically revised.
The main changes compared to the previous edition are as follows:
— xxx xxxxxxx xxx xxxx
A list of all parts in the ISO 2019# series can be found on the ISO website.
© ISO 2019 – All rights reserved v

---------------------- Page: 5 ----------------------
ISO/DIS 22444-2:2019(E)

Introduction
Rare earth metals and their alloys are key raw materials for developing high-performance rare earth
functional materials, such as hydrogen-storage materials, magnetic materials and superconducting
materials, and are widely used in fields such as sustainable energy, robotics and electronic information.
Rare earth metals are also important additive elements for aluminium-base, magnesium-base, copper-
base, titanium-base and other alloys.
This part of ISO 22444 is intended to provide a guide for producers, consumers and traders in the field
of rare earth metals and their alloys. This international standard will serve as a reference that will help
reduce discrepancies or trade disputes caused by inconsistencies in terminology used when dealing
with rare earth metals and their alloys.
vi © ISO 2019 – All rights reserved

---------------------- Page: 6 ----------------------
DRAFT INTERNATIONAL STANDARD ISO/DIS 22444-2:2019(E)
Rare earth — Terms and definitions —
Part 2:
Metals and their alloys
1 Scope
This document gives the general terms and definitions to be used for rare earth metals and their alloys,
as well as for methods of preparation and purification.
This standard can be used as a reference to unify technical terms in rare earth production, application,
inspection, circulation, trading, scientific research and education.
2 Normative references
The following ISO standard, in whole or in part, is normatively referenced in this document and
indispensable for its application.
ISO 22444-1, Rare earth – Terms and definitions – Part one: minerals, oxides and other compounds
3 General Terms and definitions
3.1 Impurity
3.1.1 Rare earth impurity
An undesirable rare earth element presents in a rare earth metal or alloy other than the specified rare
or target earth element(s).
3.1.2 Non-rare earth impurity
An undesirable non-rare earth element presents in a rare earth metal or alloy.
3.1.3 Interstitial impurity
An undesirable, non-
...