The Indium Market
Indium (symbol In) is a rare, very soft, silvery-white malleable metal with a bright luster. It is number 49 on the Periodic Table of Elements with an atomic weight of 114.81. Indium is chemically similar to aluminum and gallium, but more closely resembles zinc. Indium is a rare element and ranks 61 st in abundance in the Earth's crust at an estimated 240 parts per billion by weight. This makes it about three times more abundant than silver or mercury. Indium occurs predominantly in the zinc-sulfide ore mineral, sphalerite. Indium is produced mainly from residues generated during zinc ore processing but is also found in iron, lead, and copper ores. The average indium content of zinc deposits from which it is recovered, ranges from less than 1 part per million to 100 parts per million. Its occurrence in nature with other base metal ores is sub-economic for indium recovery. Pure indium in metal form is considered non-toxic by most sources.
Properties and Characteristics of Indium
Indium is very malleable and ductile and can be easily formed into a wide variety of fabrications. Another distinctive characteristic of indium is that it retains its softness at temperatures approaching absolute zero degrees, making it ideal for cryogenic (freezing or very low temperature) and vacuum application. The properties of indium may be summarized as follows:
- Low melting point alloy:It is useful in the high-end optical industry where lenses can be held with the alloy instead of the lens surfaces during the polishing process to minimize surface distortion.
- Lead-free and mercury-free solder industries:It is commonly used by environmentally friendly electronics goods manufacturers and high-energy alkaline dry cell batteries producers in their respective industries. This reduces or eliminates the use of lead and mercury in soldering
- Cold Welding:Oxide-free indium has the ability to cold-weld or attach to itself. Parts coated with indium can be bonded together without the application of heat or chemicals.
- Reduce gold scavenging:When soldering to gold or gold-plated surface, solder has a tendency to dissolve gold into the joint. The addition of indium to solder will reduce this tendency.
- Bond glass, quartz and ceramics:These materials cannot be bonded with traditional solders. Indium's unique cold-welding properties allow it to produce a bond in a variety of non-metal applications.
- Transparent Electrical Conductor:When indium (in the form of indium-tin-oxide) is coated onto various materials such as glass or plastic films, it acts as a transparent electrical conductor and an infrared reflector. When architectural or photovoltaic glass is coated with indium-tin-oxide, it keeps the harmful infrared rays of the sun from passing through. When coated onto automotive or aircraft windshields, it allows the glass to be electronically deiced or demisted as well as reducing the air conditioning requirement by reducing heat gain.
- Malleable:Because indium is so soft and pliable (malleable), it can easily fill voids between two surfaces, even at cryogenic (freezing or very low) temperatures.
Flat Panel Displays & LCDs
Indium is an essential raw material for a number of consumer electronics applications. The primary commercial application of indium is in coatings for the flat panel display ("FPD") industry. Indium is only useful when chemically processed with tin-oxide to form indium-tin-oxide ("ITO") to allow for electrical conductivity and optical transparency. Sputtering targets are placed in a vacuum and since ITO is conductive and optically transparent, thin layers of ITO are then applied as electrical contacts onto glass, which can in turn be used as Liquid Crystal Display (LCD) on electronic devices like television sets, computers and mobile phones. The ITO transparent conductor is currently popularly used in LCD technology due to its unique qualities of low melting point, good uniformity (which is suitable for large LCDs), fast etching time and long life span. Next generation LED backlit LCD TVs and computer monitors as well as organic light emitting ("OLED") TVs and displays all use indium.
Solar Energy Technology
Indium is increasingly being used as a crucial raw material in the solar energy industry. Copper Indium Gallium Selenide (CIGS) is a new semiconductor material comprised of copper, indium, gallium, and selenium. Its main use is for high-efficiency photovoltaic cells (CIGS cells), in the form of thin-film photovoltaic. The thin-film photovoltaic has several advantages over traditional solar energy technologies. It is lightweight, can be applied on uneven surfaces and can be rolled up when not in use. CIGS show great promise in achieving high conversion efficiencies at low costs. According to the USGS, CIGS solar cells require approximately 50 metric tons of indium to produce 1 gigawatt of solar power. Research is underway to develop a low-cost manufacturing process for flexible CIGS solar cells that would yield high production throughput. We believe that flexible CIGS solar cells could be used in roofing materials and in various applications in the aerospace, military and recreational industries.
- Indium is also used in the manufacture of low-melting-temperature alloys. An alloy consisting of 24.0% indium and 76.0% gallium is liquid at room temperature.
- Some indium compounds such as indium antimonide, indium phosphide, and indium nitride are semiconductors with useful properties.
- Indium is also used in light-emitting diodes (LEDs) and Laser Diodes (LDs) based on compound semiconductors.
- Ultrapure indium, specifically high purity trimethylindium, is used in compound semiconductors.
- Indium oxide is used as transparent conductive glass substrate in the making of electroluminescent panels.
- Indium is also used as a light filter in low pressure sodium vapor lamps.
- Indium is suitable for use in control rods for nuclear reactors, typically in an alloy containing 80.0% silver, 15.0% indium, and 5.0% cadmium.
- 111-Indium (isotope) is used in medical imaging to monitor activity of white blood cells.
Indium-Tin-Oxide (ITO, or tin-doped indium oxide) is a mixture of indium (III) oxide (In 2 O 3 ) and tin (IV) oxide (SnO 2 ), typically 90% In 2 O 3 , 10% SnO 2 by weight. It is transparent and colorless in thin layers. In bilk form, it is yellowish to grey colored powder with a molecular weight of 277.64. It is a stable ceramic-like material, insoluble in water and volatizes at 850 degrees Celsius. ITO's main feature is the combination of electrical conductivity and optical transparency. Thin films of ITO are most commonly deposited on surfaces by electron beam evaporation, physical vapor deposition, or a range of sputtering deposition techniques.
- ITO is mainly used to make transparent conductive coatings for liquid crystal displays, flat panel displays, plasma displays, touch panels, electronic ink applications, organic light-emitting diodes, and solar cells, and anti-static coatings and EMI shieldings. In organic light-emitting diodes, ITO is used as the anode (hole injection layer).
- ITO has been used as a conductive material in the plastic electroluminescent lamp of toy Star Wars type lightsabers.
- ITO is also used for various optical coatings, most notably infrared-reflecting coatings (hot mirrors) for architectural, automotive, and sodium vapor lamp glasses. Other uses include gas sensors, antireflection coatings, electrowetting on dielectrics, and Bragg reflectors in VCSEL layers.
- Reportedly, ITO is used as sensor coating in the Canon 400D/Xti and Sony Alpha DSLR-A100
- ITO thin film strain gauges can operate at temperatures up to 1400 degrees Celsius and can be used in harsh environments, ie. Gas turbines, jet engines, and rocket engines.
Production of ITO thin-film coatings accounted for approximately 84.0% of global indium consumption. Of the remaining 16.0% of the global indium market, other end uses include solders and alloys, 8.0%; compounds, 5.0%; electrical components and semiconductors, 2.0%; and research and other, 1.0%.
Supply of Indium
According to the USGS, the top six indium producing countries in the world in 2010 were China, Japan, Canada, Republic of Korea, Peru and Belgium. China’s refinery production of indium was approximately 300 metric tons in 2010. This is approximately 52% of the annual total global refined production of 574 metric tons.
According to the USGS, primary refined production of indium has been relatively flat since 2006. Annual worldwide production has ranged between 546 metric tons to 582 metric tons per year. Worldwide production actually decreased from 582 metric tons in 2006 to 563 metric tons in 2007 and edged up slightly to 573 metric tons in 2008. Worldwide production fell to 546 metric tons in 2009 and increased to an estimated 574 metric tons in 2010.
The recycling of indium has increased in recent years. The indium recycling market is now larger than primary refinery production. Recycling scrap indium into 3N7 or higher purity metal ingot is extremely complex and time consuming. According to the USGS, indium is most commonly recovered from ITO. Sputtering, the process in which ITO is deposited as a thin-film coating onto a substrate, is highly inefficient; approximately 30.0% of an ITO target is deposited onto the substrate. The remaining 70.0% consists of the spent ITO target, the grinding sludge, and the after-processing residue left on the walls of the sputtering chamber. It was estimated that 60.0% to 65.0% of the indium in a new ITO target will be recovered, and research was underway to improve this rate further. Typically, end users (ie. FPD manufacturers) establish contracts directly with the recyclers. Pursuant to such contracts, the end user supplies the recycler with scrap indium and the recycler specially processes, refines, and then returns the purified recaptured indium to the end user. Recyclers cannot sell the recycled indium to anyone else other than the end user who supplied the scrap indium. Industry insiders consider the recycling market a "closed loop". According to the USGS, it was reported that the ITO recycling loop - from collection of scrap to production of secondary materials - now takes less than 30 days. If recycling activity continues to grow and becomes more efficient, this may serve to increase the total worldwide indium supply. In the primary indium market, an increase in the price of indium does not lead to increased indium production because it is predominantly a byproduct of zinc mining. It is believed that the market price of indium does influence the rates of reclaiming and recycling of indium. The USGS does not provide specific data for the recycling market but stated that global secondary indium production increased significantly during the past several years and now accounts for a greater share of indium production than primary. The USGS also stated that this trend is expected to continue in the future and that several major secondary indium producers in Japan and the Republic of Korea announced plans to further increase their recycling capacity. MinorMetals.com reported on January 11, 2010 that 850 tons of indium was recycled in 2008, this would represent approximately 59.7% of total global indium supply based on the 573 tons of primary indium supply reported by the USGS for 2008.
According to the USGS, China controls over 50% of the world’s refined indium production. There are a number of major producers in China, but also numerous smaller producers, relying on purchasing the concentrates from the larger base-metal refiners. China produces approximately 300 to 350 metric tons of indium per year. The Chinese government restricts indium’s export with taxes. In December 2009, China announced it would reduce export taxes on unwrought indium, indium scrap and indium powder from the 10.0% to 15.0% level in 2009 to 5.0% in 2010. In December 2009, The Ministry of Commerce issued a quota allowing China to export 139.8 tons of indium in the first half of 2010, the same level as 2009. In October 2010, Bloomberg LP reported that the Ministry of Commerce in China announced the full year 2011 export quota for indium would remain unchanged from 2010 levels at 233 metric tons. The eleven licensed companies granted the largest indium export quotas for the first half of 2010 were Zhuzhou Smeltery Group Co., Ltd. — 29.4 metric tons; Nanjing Foreign Economic & Trade Development Co., Ltd. — 17.6 metric tons; Guangxi China Tin Group Co., Ltd. — 15.3 metric tons; Zhuzhou Keneng New Materials Co., Ltd — 14.2 metric tons; Huludao Nonferrous Metals (Group) I/E Co., Ltd. — 8.7 metric tons; Guangxi Debang Industry and Trade Co., Ltd. — 6.0 metric tons; Xiangten Zhengtan Nonferrous Metals Co., Ltd. — 6.7 metric tons; Hunan Jinshi Group — 6.2 metric tons; Nanjing Germanium Co., Ltd. — 7.8 metric tons; Liuzhou Yingge Metals Co., Ltd. — 5.9 metric tons and Nanjing Sanyou Electronic Materials Co., Ltd. — 4.3 metric tons. We believe that most of China’s indium output is exported, with domestic demand currently unable to sustain production.
The USGS estimated that in 2008 Canada produced 50 metric tons of indium. According to the USGS, the Canadian firm, Teck Resources Limited ("Teck"), is a long-time producer and refiner of indium as a byproduct at its facilities in Trail, British Columbia, Canada. In 2005, Teck produced 41 metric tons of indium there from concentrates. Teck announced in 2005 that it was planning to increase indium production to 75 metric tons within two years. The USGS indium data does not show any increased production of indium in Canada between 2005 and 2009, but we believe the increase may show up in the 2010 figures.
According to the USGS, the other major producer of indium in Canada is Falconbridge Ltd. In 2007, Falconbridge was acquired by Xstrata Plc, a diversified global mining company. In December 2009, Xstrata Plc announced that on May 1, 2010 it will permanently cease operation of its copper and zinc metallurgical plants at the Kidd Metallurgical site in Timmins, Ontario, Canada. According to Roskill, an information service provider of information on international metals and minerals markets, in its report titled "The Economics of Indium, 2003," the Kidd Metallurgical Division was capable of refining up to 40 tons per year of indium. All of the output from the Kidd Creek smelter was shipped to The Indium Corp. of America for further refining. According to the USGS, Xstrata produced 11 tons of refined indium at Kidd Creek in 2007 and 8 tons in 2008. In May 2010, Xstrata confirmed that the Kidd Creek smelter produced 11.5 tons of indium in 2009.
The United States does not produce any primary domestic indium and relies on imports from China, Canada, Japan, Russia, and other countries. All refined indium production in the United States during 2007 came from the refining of lower grade imported indium metal and from refining scrap. Two refineries, one in New York and the other in Rhode Island, produced the majority of indium metal and indium compounds in 2007. A number of small companies produced specialty indium alloys and other indium products. Very little indium is recycled in the United States. We believe this is because there is no infrastructure for the collection of used indium-containing products.