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can invest in processes that use less indium, through either material substitution or more efficient
manufacturing technologies. Perhaps the most important long-term response of a market to
altered incentives is technological innovation; for example, improvements to the process of ITO
sputtering (reducing the amount of waste created in sputtering) and improvements to techniques
for recycling ITO waste (increasing the recovery of the indium from the wastes of the sputtering
Section 2 describes demand for indium, Section 3 examines indium supply at present, Section 4
describes indium supply in the in the medium term (5–20 years into the future), and Section 5
describes indium supply in the long term (beyond 20 years).
Indium consumption in 2012 was estimated to be ~1,550 tonnes and was driven by the liquid
crystal display (LCD) industry in the manufacturing of flat-panel, touch-screen, and plasma
displays for televisions, computers, and handheld electronic devices. This market grew rapidly
over the past 10 years to account for ~56% of total annual consumption in the form of ITO. PV
applications made up ~8% of total consumption (Willis et al. 2012).
Indium’s use in PV in the form of copper-indium-gallium-diselenide (CIGS) solar panels is
relatively recent. Although it represents only a small fraction of current total indium demand,
improvements in both the efficiency and material intensity of CIGS solar cells can propel this
technology to be a major source of future indium demand. Currently, CIGS technology requires
~23 tonnes of indium per gigawatt (Woodhouse et al. 2012); hence, deployment of CIGS solar
panels in the tens or hundreds of gigawatts per year would require substantial increases in indium
production relative to current levels.
Figure 1. End use applications of indium
(Willis et al. 2012)
Total consumption: ~1,500 tonnes.
The remaining 36% of indium is used in a variety of applications such as solders, thermal
applications (Willis et al. 2012). According to Moss et al. (2011), other applications of indium
include low-pressure sodium lamps, bearings, dental applications, nuclear reactor control rods,
corrosion inhibitors, semiconductors for laser diodes, and low melting point alloys.
Future demand for indium likely will be driven by flat-panel displays and PV. Moss et al. (2011)
expect the market to move from a small surplus to a significant deficit in 2020 (Figure 2). Gibson
and Hayes (2011) estimate that increased demand in PV could cause indium demand to increase
at a rate of 15% per year; expansion of zinc production (the source of indium) is estimated to
increase at only ~1% to 3% per year.
Figure 2. Indium supply and demand forecasts
(Moss et al. 2011)
SMG Indium Resources (SMG) believes demand is likely to persist because there is currently no
comprises only a very small fraction of the materials used in an ITO target (~1%). Therefore, it
represents only a small proportion of total input costs in manufacturing of LCDs, so
manufacturers are likely to be able to absorb significant price increases before being required to:
(1) reduce the quality of indium used; (2) find a substitute; or (3) change technologies.
Given the potential for significant demand growth and concerns about availability, speculation in
indium markets has resulted in indium being increasingly bought as an investment mineral—a
business model being pursued by SMG, which was formed to purchase and stockpile indium
ingots with a minimum purity level of 99.99% (SMG Indium Resources 2010). Although indium
will probably not develop into an exchange-traded fund, the attractive supply demand
fundamentals have created a new type of consumer who is interested in investing in funds
backed by indium. As of April 2014, SMG indium stockpiles were reported to be 21 tonnes
(SMG Indium 2014).
With rare exceptions, indium has not been mined as a main product, but rather as a byproduct
from the refining of base metals. Almost all commercially produced indium is extracted from
zinc refining. Indium often also occurs in deposits of silver, copper, lead, and tin; but in these
instances, it normally occurs at subeconomic concentrations.
Indium’s abundance in the Earth’s crust ranges from 0.05 to 0.072 parts per million (ppm)
(Schwarz-Schampera and Herzig 2002), and where it is economic to recover in zinc sulfide
deposits, it often is concentrated in ranges from less than 1 ppm to 100 ppm. However, not all
zinc deposits contain indium, and for those that do, concentrations vary considerably.
A European Commission study into the availability of certain “critical minerals” recently
estimated global production of refined indium at 1,345 tonnes per annum (tpa) from primary and
secondary sources (Moss et al. 2011). The U.S. Geological Survey (USGS) estimates that
primary indium refinery production was 770 tonnes in 2013 (Tolcin 2014a). China accounted for
the largest proportion of this with 410 tonnes, which is consistent with China’s leading position
in zinc production (Tolcin 2014a, 2014b).
Figure 3 depicts indium’s value chain. As mentioned earlier, primary indium is usually a
byproduct from zinc mining. Zinc ores and indium-bearing zinc concentrate are generally
concentrated at the mine site; then the zinc is shipped to smelters for further refining. If the zinc
concentrate is shipped to an indium-capable smelter, the concentrated indium needs to be
additionally refined by a special metals plant to upgrade it for commercial use. Once the required
level of indium metal is produced, it can be formed into ingots, wires, or ITO powders. Where
the indium is to be used in PV or LCDs, it is sputtered onto thin-films. The sputtering process is
not very efficient: only about 30% of the indium is successfully deposited onto the thin-films
when using the most typical sputtering targets that have a planar configuration. Given the low
deposition efficiency of the planar sputtering targets, many manufacturers reuse the indium lost
in the manufacturing process by sending the spent ITO targets and order residues to special
recycling plants to recover the unused metal. The indium that is successfully deposited makes its
way into consumer products and will once again be available for recovery at the end of the
products’ useful lives. Currently, the costs of waste separation are high and the fraction of
indium (as a percentage of total mass) contained in many electrical devices is small; thus,
recycled EOL products do not constitute a material source of indium supply.
The following subsections examine various aspects of indium’s value chain in greater detail.