Unranium-Oxide
Uranium oxide is often referred to as 'yellowcake.' It is a radioactive mineral consisting of opaque black, brown or grey crystals with a greasy lustre.
Uranium oxide is also known as uraninite, the ore from which commercial levels of uranium is generally extracted. Uraninite is normally mined from sedimentary rocks such as sandstone and hydrothermal vein deposits. It is also a by-product of silver and gold processing. Uranium is a metallic chemical element that has a low radioactive presence but the highest atomic weight of all the naturally occurring minerals. It has a lower density to that of gold but is 70 percent more dense than lead. It is sought after for both civilian and military uses but more noticeably in nuclear technology because of its ability to create a sustained nuclear chain reaction.
The ore containing uranium is usually processed immediately it is mined and turned into yellowcake to make it easier to transport for further processing. The yellowcake is actually uranium oxide concentrate, an insoluble yellow powder that consists of around 80 percent uranium oxide.
To produce uranium oxide the ore containing the uranium has to be ground and mixed with water until it becomes a mud. This mixture is then oxidised with the use of ferric sulphate that dissolves into sulphuric acid. The resulting uranium rich liquid is then separated and put into contact with special resin beads that absorb all the uranium ions. The uranium is removed from the resin beads by means of an acid wash and a very concentrated uranium solution results. The next step involves combining an organic solvent with the uranium rich solution and this is then mixed with ammonium sulphate. The precipitation that results from this action creates a substance called ammonium diuranate, a mixture of ammonia and uranium oxide. This substance is thickened and removed with the use of rotating filters which is known as yellow paste. The paste is then roasted to remove the ammonia leaving uranium oxide alone in it's place. This uranium oxide can be further processed to produce enriched uranium oxide fuel. This product is sealed into special metal fuel rods that, in turn, are fitted into nuclear reactors that produces the heat required to generate electricity.
A by-product of this process is what is known as depleted uranium oxide, this substance is no longer radioactive. Once uranium oxide is depleted it can be used in situations where large masses have to be made fit in small places, for example, as yacht keels and helicopter counterweights. Depleted uranium oxide is also used in the production of radiation shielding being far more effective than lead and also in ceramic and glass products as colourants.
Australia has the world's largest uranium resource with 33 percent of the world's total that is able to be recovered for less than $130 a kilogram. There are currently four mines producing uranium in Australia; the Ranger Mine in the Northern Territory and the Olympic Dam, Beverley and Honeymoon mines in South Australia. The Honeymoon Mine is the latest to start production having been commissioned in 2011.
Uranium naturally occurs in the Earth's crust, with traces to be found virtually everywhere but it is only when uranium becomes concentrated in the one area that it becomes feasible to mine. It is primarily mined for used as nuclear fuel. The rocks that contain concentrated uranium are known as uranium ore from which the uranium has to be extracted. It is carefully traced from when it is mined right through to when it reaches it final destination. The Australian government only allows uranium sales to certain countries that it considers will not allow it to be used in the manufacturing of nuclear weapons.
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.
