Post on 19-Jan-2021
Element Cycles and Criticality :
A Focus on Minor Metals
Thomas E. Graedel
Yale University
Center for Industrial EcologyYale School of Forestry & Environmental Studies
Important Points About Minor Metals
• Minor (or “specialty”) metals are vital to many modern technologies, as shown by their fast-changing uses
• Minor metals are mostly available only as by-products
• Minor metals have few good substitutes• Minor metals have very low end-of-life recycling
rates• Minor metals have high levels of criticality
compared with most more common metals
0
40 000
80 000
120 000
160 000
200 0001
96
5
19
67
19
69
19
71
19
73
19
75
19
77
19
79
19
81
19
83
19
85
19
87
19
89
19
91
19
93
19
95
19
97
19
99
20
01
20
03
20
05
20
07
met
ric
ton
s
Year
Global Uses of Antimony, 1965-2009Other
Batteries(industrial)
Batteries(transportation)
Flame retardants
Chemicals
Ceramics and glass
Elements Addressed in the Yale Criticality Project
The “companionality” of metals: the production of many metals is dependent on the production of carrier metals
% of primary production as companion
20 40 5030 60 80 90 10070100
Source: N. T. Nassar, T. E. Graedel, E. M. Harper, Byproduct metals are technologically essential but have problematic supply. Science Advances, in press (2015).
Scrap
W
U
F
C
Min
Mfg
W 2008 (Gg/a) - World
© Yale University 2015
56
56
76
23
0 8
0
22
68
68
7
76 68
68
68
68
0
1
1
Tungsten global
cycle, 2008, Gg/a
(UNEP, Recycling rates of metals, 2011)
End-of-life recycling rates of metals
Source: Graedel, T. E.; Harper, E. M.; Nassar, N. T.; Reck, B. K., On the materials basis of modern society. Proceedings of the National Academy of Sciences 2013, doi: 10.1073/pnas.1312752110.
Substitute performance
20 40 5030 60 80 90 10070100Excellent Poor
The substitutability of metals
Re: Jet engines
Y: Phosphors
Rh: Catalytic converters
Eu: Phosphors
Criticality –
The quality, state, or degree
of being of the highest
importance
Supply Risk
Geological, Technological,
Economic
Depletion
Time
Companion
Metal Fraction
Social &
Regulatory
Policy Potential Index
Human Development
Index
Geopolitical
WGI – Political Stability
Global Supply Concentration
Vulnerability to Supply Restriction
Importance
Material Assets
National Economic
Importance
Substitutability
Substitute Performance
Substitute Availability
Environmental Impact Ratio
Net Import Reliance Ratio
Susceptibility
Net Import Reliance
Global Innovation
Index
Supply Risk
Vu
lne
rab
ility
to
Su
pp
ly R
est
rict
ion
Environmental Implications
Human Health Ecosystems
Cradle-to-gate lifecycle inventory
The 3-Axis Approach to Criticality
Silver criticality – global level
In
Supply Risk
Vu
lner
abili
ty t
o S
up
ply
Re
stri
ctio
n
The three-dimensional criticality of the 62 metals of the periodic table
0
20
40
60
80
100
0 20 40 60 80 100
VSR
G
SRL
Tl
Ag
(a)
Light metals Specialty metals Iron & its principal alloying elements Superalloy metals Copper group
Zinc, tin, lead group Rare earth elements Nuclear energy metals Platinum-group metals
Global-Level Criticality Assessment: Supply Risk and Vulnerability Axes
InSb
As
0
20
40
60
80
100
0 20 40 60 80 100
EI
SRL
Light metals Specialty metals Iron & its principal alloying elements Superalloy metals Copper group
Zinc, tin, lead group Rare earth elements Nuclear energy metals Platinum-group metals
(b)
Global-Level Criticality Assessment: Supply Risk and Environmental Axes
Rh
Pd RuIr
Characteristics of High Criticality
• Largely or entirely available only as a byproduct of more abundant carrier metals
• Used in small quantities in specialized high-technology applications
• Has no suitable substitute or substitutes across its spectrum of uses
A Thought to Take With You
By-product metals rank quite high in long-term criticality. Their recovery from ores (and long-term storage, if necessary) should be strongly encouraged lest moderntechnology become strongly constrained