Indium
Indium (In) is an easily fusible post-transition metal that is malleable, soft and rare in nature. It is chemically similar to both thallium and gallium.
Indium is a chemical element that is obtained primarily from zinc ores where it is found in compound form. It is rarely found as grains of native metal. Its properties are akin to those of thallium and gallium.
Indium, was discovered in 1863 and first called “Indigo Blue” because of an indigo blue line in its spectrum that first drew attention to its existence in zinc ores. It was isolated as a metal in 1864.
Primary Uses of Indium:
- As indium tin oxide, a transparent electrode in liquid crystal displays and computer and TV touch-screen (LCDs)
- As a thin film in lubrication usage to coat bearings in high performance aircraft during the Second World War
- As a low melting point alloy lead free solder
- Radioactive indium is used in small quantities in nuclear medical tests, such as in a radio-tracer by highlighting white blood cells and the movement of labelled proteins in the body
Worldwide production of indium is about 475 tonnes annually mainly because of the demand in the production of LCD computer and television screens. Recycling accounts for a further 650 tonnes a year. 50 percent of indium use is now taken up with the demand coming from the manufacturers of LCD screens. It is estimated that there is only 20 years of indium available in the world based on current mining supplies which draws attention to the need of successful recycling programs being continued and further developed throughout the world.
The worldwide lack of indium mineral deposits and the fact that indium is enriched in mainly zinc deposits and to a smaller extent in iron, copper, tin and sulphidic lead, makes the production of zinc the main source for indium. Indium is leached from the dust and slag left over when producing zinc. It is then purified by electrolysis, a process that varies according to the composition of the slag and dust being processed. In 2012 China produced 390 tonnes of indium making it the world's leading indium producer. Canada, Japan and South Korea followed with 70 tonnes each.
Indium is a silvery white metal that is quite soft and has a brilliant lustre. When bent, in its purest metal form, it emits a high pitched “scream.” It wets glass in the same way as does gallium and is perfect for making low melting alloys, in fact an alloy containing 76 percent gallium and 24 percent indium is a liquid at room temperature.
Indium, despite it being claimed to be more prolific in the Earth's crust than silver, is not mined in the conventional manner. In fact, there are no dedicated indium mines anywhere in the world. This is mainly because where it does exist it is usually in such low concentration. It costs a lot of money to set up a mine to extract any metal ore that has to be refined before the product becomes of any value to a buyer.
In the case of indium, the market demands the product has to be close to 100 percent pure before it is of any use. In fact, to use indium successfully in high-tech situations a purity of 99.995is needed. In some applications, such as that of semiconductor usage, a purity of 99.9999 is required.
Australian Mines that produce Bauxite
Gove (NT)
Up to 600 workers employed at the Gove bauxite refinery in the Northern Territory face an uncertain future as Pacific Aluminium suspends alumina production.
Ely (QLD)
The Ely Alcan Queensland Pty Ltd agreement at the Weipa bauxite mine is due to expire in 2041 but an option will give it a further 21 years extension.
Skardon River (QLD)
Gulf Alumina acquired 100 percent of the Skardon River tenement in 2011 from its koalin mining joint partner to develop the mining of bauxite at the site
Weipa (QLD)
The Weipa bauxite mine on the western side of the Cape York Peninsula in northern Queensland is both owned and operated by Rio Tinto Alcan.
Huntly (WA)
The Huntly mine in Western Australia is the largest bauxite mine in the world currently producing about 23 million tonnes of bauxite annually.
Willowdale (WA)
The Willowdale bauxite mine that commenced production in 1984 still processes 10 million tonnes of bauxite a year at the nearby Wagerup Refinery.
Worsley (WA)
The Worsley bauxite mine and alumina refinery in South West Western Australia employs more than 1,800 people and produces 4.6 million tonnes of alumina annually.
South Aurukun (QLD)
The South Aurukun bauxite tenements on the Cape York Peninsula in Far North Queensland are held by Gulf Alumina.
Marchinbar Island (NSW)
The Marchinbar Island bauxite deposit in far north Northern Territory could be mined to satisfy a growing demand from China in the near future.
Kwinana Refinery (WA)
The Kwinana refinery in WA employs around 1,000 direct employees with 60 percent living in the nearby towns of Rockingham, Cockburn and Kwinana.
Wagerup Refinery (WA)
The Alcoa owned Wagerup alumina refinery in W.A. has received governmental approval to lift alumina production from 2.6 to 2.65 million tonnes annually.
Pinjarra Alumina Refinery (WA)
The Pinjarra alumina refinery, near Mandurah south of Perth, is an important part of Alcoa's three refinery system in Western Australia.
Portland Aluminium Smelter (VIC)
The Portland Aluminium smelter in western Victoria, a joint venture operation between Alcoa, CITIC and Marubeni, caters solely to the Asian market.
Felicitas (WA)
The Felicitas bauxite project in Western Australia contains a bauxite resource of 220 million tonnes that will give it a life of mine of 25 years
South Of Embley (QLD)
Despite Rio Tinto placing its South of Embley bauxite project in Cape York, Queensland, on hold for 18 months it still considers it a 'good project.'
Bauxite Hills (QLD)
The Bauxite Hills Project on the Cape York Peninsula in Queensland is hoping to take advantage of an expected increase in the demand for Alumina.
Bald Hill (TAS)
Australian Bauxite Limited's Bald Hill mine, in Tasmania, is to start production in December, 2014. It is the first new bauxite mine in Australia, for over 35 years.
Urquhart Point (QLD)
The Urquhart Point Heavy Mineral Sands Project in Cape York in Far North Queensland is expected to begin production in mid-2015.
Amrun (QLD)
The Amrun bauxite project in far north Queensland, that was previously known as the 'South of Embley' project has been approved for development and expected to be in production by 2019.
