65
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications
Appendix B: Secondary Production
Table 25. Overall Recovery Efficiency of Indium Use in a Hypothetical ITO
Sputtering Application With Closed Loop Recycling of Manufacturing Waste
Where Total Measured Indium Recycled Is ~608.5 Tonnes
Indium Secondary Production Loop
Cycle
1
2
3
4
5
6
7
8
9
10 Total
Units available for ITO
729
c
332 151 69
31
14
6
3
1
1
1,337
d
Units successfully
deposited
a
219
c
99
45
21
9
4
2
1
0
0
401
e
Units available for
recycling
a
510
232 106 48
22
10
5
2
1
0
936
f
Units successfully
recycled
b
332
151 69
31
14
6
3
1
1
0
609
g
Units forever lost
179
81
37
17
8
3
2
1
0
0
328
h
% of indium deposited
55%
% of indium wasted
45%
a
Deposition success rate assumed to be 30%; therefore, 70% of indium is available for recycling. We assume that if
indium is not successfully deposited upon application of ITO, it is available for recycling. In other words, there are no
“losses” at the manufacturing stage--only at the recycling stage.
b
Indium recycling efficiency estimated to be 65% per recycling cycle.
c
Primary indium. All other figures relate to indium that is either entering recycling or has been recycled.
d
If 729 tonnes of primary indium become used in ITO applications with recycling, the ITO applications will appear
to have consumed 729 tonnes (primary) + 609 tonnes (secondary) indium. The figure of 1,337 units of indium is
likely the figure of indium demand reported by manufacturers.
e
Of the original 729 tonnes of primary indium entering the manufacturing process, 401 tonnes (55%) is effectively
deposited when factoring in that spent ITO targets and other manufacturing wastes are recycled.
f
Out of every 729 tonnes of primary indium used in ITO applications, 936 tonnes might appear to be entering the
recycling plant, because the same indium may enter the plant more than once per period.
g
Out of every 729 tonnes of primary indium used in ITO applications, 510 tonnes actually enters the recycling plant.
Because the 510 tonnes enters more than once, the plant appears to produce 609 tonnes of refined indium over 10
cycles. This figure of 609 tonnes is most likely representative of recycling plant throughput as measured by
producers.
h
Of the 729 tonnes of primary indium entering the manufacturing process, 328 tonnes (45%) is forever lost. This is
due to a combination of (1) deposition efficiency, which drives the number of times the same indium must be
recycled; and (2) recycling efficiency.
Sources: Own calculations; Mikolajczak 2009
66
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications
Appendix C. Metal Prices
Figure 27. Historical zinc and tin prices in 2011 USD as indicated
1
In 2011 USD terms, since 1960 zinc averaged $1.07/kg with a high of and minimum price of $0.65/kg in 1962 and a
maximum of $2.61/kg in 2006. Over the same period, the tin price has averaged $9.67/kg, reaching a minimum of $3.92/kg
in 2002 and a maximum of $18.13 in 1979.
2
Tin price surged in the early 1980s and its subsequent collapse may have been due to market manipulation (Anderson and
Gilbert 1988).
3
Metal prices from the World Bank were adjusted to 2011 USD using the Manufactures Unit Value Index, a proxy for the
price of developing country imports of manufactures in USD. The index is a weighted
average of export prices of
manufactured goods for the G-5 economies, with local currency-based prices converted into current USD using market
exchange rates.
4
Derived from World Bank (2012).
0.00
0.50
1.00
1.50
2.00
2.50
3.00
0
2
4
6
8
10
12
14
16
18
20
19
60
19
62
19
64
19
66
19
68
19
70
19
72
19
74
19
76
19
78
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02
20
04
20
06
20
08
20
10
Zi
nc
m
et
al
p
ric
e
(2
01
1 U
S$
/k
g)
Tin
m
et
al p
ric
e
(2
01
1 U
S$
/k
g)
Historical zinc and tin prices (1960-2011)
Tin (US$/kg) (lhs)
avg. Sn: 9.67 US$/kg (lhs)
Zinc (US$/kg) (rhs)
avg. Zn: 1.07 US$/kg (rhs)