Cadmium
Cadmium (Cd) is a chemical element. In metal form it is bluish-white and chemically similar to mercury and zinc. Traces of cadmium occur naturally in phosphates.
Most people are aware of cadmium being a major component in the manufacturing of re-chargeable nickel-cadmium batteries and its wide use in electroplating of steel as a prevention against corrosion. Deposits of cadmium are extremely rare and when they are located they are usually quite small. It is, however, a natural occurring trace element of phosphate.
Cadmium is Obtained as a By-Product of the Smelting and Refining of Sulphide Ores
The only cadmium mineral of any economic importance is that of Greenockite (CdS) that is mostly associated with sphalerite (ZnS). It is, in the main, obtained for commercial purposes as a by- product in the mining industry through the smelting and refining of sulphide ores of copper and lead, specifically zinc.
Cadmium has a close resemblance to mercury and zinc. It is soft and in metal form a bluish-white colour. It is both ductile and malleable and is highly resistant to corrosion. It has wide uses in industry but by far its main use is in re-chargable batteries and in electroplating steel.
Cadmium is Inflammable but can Release Toxic Fumes
Cadmium is non-burnable and when in solid form it releases toxic fumes. It is also insoluble in water. It is considered an undesirable product in fertiliser and its production is forbidden in some countries because of environmental concerns. China is the largest producer of cadmium having produced more than 5,600 tonnes in 2010.
Cadmium Used by Van Gogh, Edison and Junger
Cadmium is present throughout the environment and is naturally occurring in both the Earth's water and crust. It was first isolated in Germany in 1817 as a by-product of zinc refining. It found use in the 1850's as a pigment used in paintings because of its brilliant yellow, orange, and red colours. In fact cadmium sulphide was used by Vincent Van Gogh in his painting in the late 1800's. Cadmium was produced in Germany before World War One for industrial purposes and Waldemar Junger in Sweden along with Thomas A. Edison in the United States created the first nickel-cadmium batteries in the early years of the 20th century. The most important use, however, was as a corrosion protection in the coating of steel and iron products.
Recycling of Cadmium Responsible for 23 Percent of the Worlds Supply
Cadmium metal is produced today as a by-product following the smelting and refining of nonferrous metals such as copper, lead and zinc. Instead of engineers having to worry about disposing is as waste into the environment it is now collected and sold for various industrial applications. It is also obtained by recycling used nickel-cadmium batteries. Recycling accounts for 23 percent of the total world supply of the metal.
Cadmium is not Readily Bio-Available
Cadmium embedded into the products it is used in do not leach as do many other metals. This makes it not readily bio-available. For example; plastic, glass, enamel and ceramic products coloured with the use of cadmium sulphide pigments are all completely insoluble and pose no danger to the environment.
Cadmium Exposure Successfully Addressed
Uncontrolled exposure to cadmium either through excessive concentrations or long term association with the raw product can be injurious to human health especially to a persons kidneys or lungs. Workers in the industry who are occupationally exposed are the most vulnerable, however, exposure levels throughout the world are now under strict control and all workers who are occupationally exposed are continuously monitored and kept at a safe level at all times.
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.
