34
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications
4 Supply: the Medium-Term Outlook (5–20 years)
When thinking about supply in the medium term (loosely defined here to be 5–20 years),
additional indium supply can come from several additional sources. As shown conceptually in
Figure 17, these sources include:
•
Increased recovery efficiency. This can be either through operational improvements, or
by ensuring that indium contained in zinc or other base metal concentrates is shipped to
indium-capable smelters and refineries.
•
Operations that currently do not recover indium. This can occur by expanding or
modifying processing facilities to recover indium that is currently not recovered. Because
this option would require an investment in new technologies or capacity, it requires that
prices and metal recoveries justify the additional capital and operating costs.
•
New byproduct production. This could be through the byproduct recovery of indium
from zinc (or other) mines that currently are not in production. Indium would be
recovered as a byproduct in these cases, so the price required to justify its recovery would
need to cover the incremental costs only; all other costs (such as mining, administration,
and other fixed costs) would be allocated to main product production.
•
Increased secondary production from EOL materials (i.e., recycling of consumer
waste).
•
Increased secondary production from the recycling of manufacturing waste. This
can be done by: (1) increasing the efficiency of the
secondary refining process; and (2)
increasing the quantity of manufacturing waste being recycled.
•
Recovery of indium through new main product supply, which might occur if indium
deposits are discovered and developed where the principal metal of economic
interest is indium. To
our knowledge, there are currently no main product indium
producers; however, the Toyoha mine in Japan has produced main product indium in the
past. Main product indium is normally high-cost indium because the indium content of
the deposit has to justify all costs associated with developing the property, including the
initial discovery costs, mining, treatment, and administration costs as well as the costs of
associated capital (i.e., the investment must earn a minimum required return on capital).
35
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications
Figure 17. Illustrative medium-term indium supply curve
4.1 Expansion of Zinc (or Other Main Product) Production
Between 2007 and 2011, zinc production expanded at a CAGR of 2.4% (Appendix A). The
International Lead and Zinc Study Group forecast production growth at 3.9% (White 2012), with
increased output anticipated at a number of Peruvian, Bolivian, and Mexican mines. With these
increases to zinc production in mind, and given production of ~730 tpa of indium (mainly
derived as the byproduct from zinc production), we extrapolate medium-term indium production
on the basis of historical expansion of zinc production. This is shown below for growth scenarios
of 2%–3% annual expansion of zinc production. As Table 12 shows, on this basis, 2016
production could be 807–847 tonnes with an average of 827 tonnes. If this expansion continues
until 2031, byproduct indium production could reach ~1,200–1,531 tonnes. For our estimates we
use average values of 827 tonnes and 1,365 tonnes in 2016 and 2031, respectively.
Table 12. Medium-Term Estimates of Indium Primary Refinery Production
Main product growth
a
CAGR, %
2011
2016ᵇ
2031ᵇ
2.0%
731
807
1,199
3.0%
731
847
1,531
Average
731
827
1,365
a
Main product CAGR ranged based on historical zinc production growth between 2007 and 2011 as calculated from
USGS data and estimates from the International Lead and Zinc Study Group (White 2012).
b
Assumes that recovery rates continue and that the proportion of hydrometallurgical processing remains unchanged
over the extrapolation period.
To identify individual producers that are likely to form part of medium-term supply, we surveyed
company reports and identified the following six advanced stage deposits that have a potential
combined supply contribution of 150–155 tpa. The two largest potential new sources of supply
are the Mount Pleasant deposit in eastern Canada, with a potential to produce 38.5 tpa of indium,
and the Maklu Khota deposit in Bolivia, with a potential production of 76 tpa. Summary
0
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2,500
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4
Co
st
:
$
/k
g m
et
al
pr
oduc
ed
Annual output
Critical Element Supply Curve
Existing production at
existing efficiencies
Increasing
recovery
efficiency
New main-
product supply.
Add recovery circuit
to existing refineries
Note: For illustrative purposes only.
Deposit 1
Deposit 100+
Increased recovery efficiency and new
sources of supply can shift and extend the
supply curve over the medium to long run.
Recycle consumer
waste
