28
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications
Finally, because secondary supply from new scrap decreases with each cycle of recycling, Table
9 also highlights that, if primary supply were to cease for whatever reason, secondary supply
from new scrap would decrease geometrically and cease altogether within a very short period.
Thus, although secondary supply from manufacturing waste can buffer market shocks in the
short term, it does not isolate manufacturers from prolonged primary supply disruptions.
This sample analysis should lead readers to be cautious when estimating total demand and
supply. As we have illustrated, when considering sources of supply, secondary production from
new scrap introduces significant potential for double counting in estimates for both supply and
demand. To eliminate this risk, secondary supply from new scrap should rather be seen as a
reduction in the demand for primary indium.
3.7.1 Recycling Process
The technology used in recycling indium is mostly proprietary. Although recovery techniques
differ,
27
Roskill (2010) describes a process in which indium is recovered from spent ITO targets
through the following steps:
1. Nitric acid is used to form indium nitrate, followed by neutralization, which produces
indium hydroxide.
2. Indium oxide is formed through thermal decomposition and dissolved in sulfuric acid.
3. Metallic indium can be produced from the resulting solution electrolytically (Roskill
2010).
As
previously discussed, refining capacity to reclaim spent ITO targets has expanded
considerably since 1996 to reduce primary demand for indium. Japan, China, and to a lesser
extent, South Korea and Belgium, have most of this capacity (Table 10 and Figure 13). The
geographic dispersion of secondary production is expected, because recyclers of new scrap can
reduce transportation costs and cycle times by locating close to high-tech manufacturing centers
that sputter ITO in the manufacturing of LCDs or other applications.
3.7.2 Estimates of Secondary Supply
A bottom-up analysis of global secondary indium production indicates that ~610 tonnes of
refined indium are “measured” as being produced through the recycling of manufacturing waste,
most of which is sourced through the application of ITO in flat-panel displays.
28
Roskill (2010) states that total secondary indium production was ~602 tonnes in 2009; Indium
Corp. estimates that ~1,000 tonnes of indium is produced from new scrap every year
(Mikolajczak 2009).
The geographic dispersion of secondary production (Figure 13) is located close to where most
LCD manufacturing takes place: Japan, China, and South Korea.
27
For example, Han et al. (2002) describe a process for the recovery of indium from ITO consisting of chemical precipitation
followed by solvent extraction.
28
As discussed earlier, it’s important to highlight that “measured” secondary production from new scrap can be significantly
overestimated because of the potential for double counting in a closed-loop recycling environment.
29
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications
Table 10. Indium Recycling Capacity of Known Producers (2013)
Source: Own estimates; Roskill (2010)
Location
Country
Operating Company/Investors
Indium (tpa)
Hoboken
Belgium
Umicore
50.00
Hydrometal-Lien
plant
Belgium
Hydrometal SA, Jean Goldschmidt
International S.A
0.50
Trail Smelter
Canada
Teck Resources Limited
5.00
Nanjing 718 factory
China
Nanjing Germanium Factory Co. Ltd.
150.00
Fremat Freiberg
plant
Germany
Gfe Fremat GmbH
1.00
Fukuoka
Japan
Asahi Pretec Corp
200.00
Kosaka plant
Japan
Akita Rare Metals, Dowa Holdings Co., Ltd
150.00
Hitachi metal
recycling complex
Japan
Nikko Environmental Services Co,
Nippon Mining and Metals Co. Ltd.
6.00
Onahama
Japan
Onahama Smelting and Refining Co., Ltd, of
which Mitsubishi Materials Group owns 50%
6.00
Onsan
South
Korea
Korea Zinc Co. Ltd.
40.00
Total
608.50
Figure 13. Geographic distribution of secondary refined indium
Source: Own estimates; company reports; Roskill 2010
Using the values from Table 10, if one assumes that 608.5 tpa of refined indium are produced,
938 tonnes
29
of indium enter the recycling process and approximately 330 tonnes are lost due to
refining inefficiency any given year. Similarly, ~1,341 tonnes
appears to be demanded by
29
Calculated using the ratios in Table 10 as
608.5
83
128
x =
. Solving for ‘x’ yields ~938 tonnes. Similarly, solving for ‘y’ in
608.5
83
183
y
=
., yields ~1,341 tonnes. More detail is provided in Appendix B.