Aluminium oxide is an amphoteric oxide of aluminium with the chemical formula Al2O3. It is also commonly referred to as alumina or aloxite [1] in the mining, ceramic and materials science communities. It is produced by the Bayer process from bauxite. Its most significant use is in the production of aluminium metal, although it is also used as an abrasive due to its hardness and as a refractory material due to its high melting point. [2]
This is a list of countries by aluminium oxide (alumina) production in 2023. [3]
* indicates "Natural resources of COUNTRY or TERRITORY" links.
| Country (or area) | Production (in thousand tonnes) |
|---|---|
 China * | 82,000 |
 Australia | 19,000 |
 Brazil * | 10,000 |
 India * | 7,300 |
 Russia * | 2,400 |
 United Arab Emirates | 2,300 |
 Saudi Arabia | 1,800 |
 Canada * | 1,600 |
 Jamaica | 1,500 |
 Vietnam * | 1,400 |
 Kazakhstan * | 1,300 |
 Indonesia * | 1,200 |
 Ireland | 1,200 |
 Greece | 860 |
 United States | 780 |
 Germany | 720 |
 Spain | 640 |
 Guinea * | 330 |
 Turkey * | 290 |
| Other Countries | 880 |
| World | 140,000 |
Aluminium is a chemical element; it has symbol Al and atomic number 13. Aluminium has a density lower than that of other common metals, about one-third that of steel. It has a great affinity towards oxygen, forming a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, nonmagnetic, and ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the twelfth-most common element in the universe. The radioactivity of 26Al leads to it being used in radiometric dating.
Bauxite is a sedimentary rock with a relatively high aluminium content. It is the world's main source of aluminium and gallium. Bauxite consists mostly of the aluminium minerals gibbsite, boehmite and diaspore, mixed with the two iron oxides goethite and haematite, the aluminium clay mineral kaolinite and small amounts of anatase and ilmenite . Bauxite appears dull in luster and is reddish-brown, white, or tan.
Aluminium oxide (or aluminium(III) oxide) is a chemical compound of aluminium and oxygen with the chemical formula Al2O3. It is the most commonly occurring of several aluminium oxides, and specifically identified as aluminium oxide. It is commonly called alumina and may also be called aloxide, aloxite, or alundum in various forms and applications. It occurs naturally in its crystalline polymorphic phase α-Al2O3 as the mineral corundum, varieties of which form the precious gemstones ruby and sapphire. Al2O3 is used to produce aluminium metal, as an abrasive owing to its hardness, and as a refractory material owing to its high melting point.
The Hall–Héroult process is the major industrial process for smelting aluminium. It involves dissolving aluminium oxide (alumina) in molten cryolite and electrolyzing the molten salt bath, typically in a purpose-built cell. The process conducted at an industrial scale, happens at 940–980 °C and produces aluminium with a purity of 99.5-99.8%. Recycling aluminum, which does not require electrolysis, is thus not treated using this method.
Aluminium hydroxide, Al(OH)3, is found in nature as the mineral gibbsite and its three much rarer polymorphs: bayerite, doyleite, and nordstrandite. Aluminium hydroxide is amphoteric, i.e., it has both basic and acidic properties. Closely related are aluminium oxide hydroxide, AlO(OH), and aluminium oxide or alumina, the latter of which is also amphoteric. These compounds together are the major components of the aluminium ore bauxite. Aluminium hydroxide also forms a gelatinous precipitate in water.
Rio Tinto Alcan is a Canada-based mining company. Headquartered in Montreal, Quebec, it is a subsidiary of global mining conglomerate Rio Tinto. It was created on 15 November 2007 as the result of the merger between Rio Tinto's Canadian subsidiary and Canadian company Alcan.
The Bayer process is the principal industrial means of refining bauxite to produce alumina (aluminium oxide) and was developed by Carl Josef Bayer. Bauxite, the most important ore of aluminium, contains only 30–60% aluminium oxide (Al2O3), the rest being a mixture of silica, various iron oxides, and titanium dioxide. The aluminium oxide must be further purified before it can be refined into aluminium.
The Deville–Pechiney process, also known as the Le Châtelier process, was the first industrial process used to produce alumina from bauxite.
National Aluminium Company Limited is an Indian public sector company having integrated and diversified operations in mining, metal and power. Presently, the Government of India holds a 51.28% equity stake in NALCO, while the Ministry of Mines has administrative control over the company.
Alcoa World Alumina and Chemicals is a owned 100% by Alcoa Corp. and is abbreviated to AWAC. AWAC's business is the mining of bauxite, the extraction of alumina and the smelting of aluminium. It has about 25% of the global alumina market. Alcoa acts as the day-to-day manager.
Carl Josef Bayer was a chemist from Austria-Hungary who invented the Bayer process of extracting alumina from bauxite, essential to this day to the economical production of aluminium.
Aluminum Corporation of China Limited, is a state-owned multinational aluminium company headquartered in Beijing, People's Republic of China. It is a publicly-traded company, listed in Hong Kong and in Shanghai. In 2021, it was the world's largest aluminum producer, ahead of China Hongqiao Group, Rusal and Shandong Xinfa.
Aluminium recycling is the process in which secondary commercial aluminium is created from scrap or other forms of end-of-life or otherwise unusable aluminium. It involves re-melting the metal, which is cheaper and more energy-efficient than the production of virgin aluminium by electrolysis of alumina (Al2O3) refined from raw bauxite by use of the Bayer and Hall–Héroult processes.
Aluminium in Africa originates from bauxite, and within Africa is primarily found in Guinea, Mozambique and Ghana. Guinea is by far the biggest producer in Africa, and is a world leader in bauxite production.
United Company Rusal is the world's second largest aluminium company by primary production output. It was the largest until overtaken by China Hongqiao Group in 2015. Rusal accounts for almost 9% of the world's primary aluminium output and 9% of the world's alumina production. Rusal was founded by major Russian industrialist Oleg Deripaska.
Aluminium smelting is the process of extracting aluminium from its oxide, alumina, generally by the Hall-Héroult process. Alumina is extracted from the ore bauxite by means of the Bayer process at an alumina refinery.
Bauxite mining in Australia is an economically significant industry both for Australia and globally. The industry focuses on the mining of bauxite, the primary raw material for alumina and aluminium. Australia is the world's largest bauxite producer, producing almost a third of global bauxite.
According to the United States Geological Survey, Vietnam is estimated to hold the world's third-largest bauxite ore reserves after Guinea and Australia. The majority of Vietnam's reserves are located in the Central Highlands and have only been minimally mined. Bauxite is typically strip mined and is used to produce aluminum. According to estimates by Vietnam's Ministry of Industry and Trade, Vietnam's reserves in the Central Highlands amount to 5.4 billion tons. Despite its large reserves, Vietnam produces only 30,000 tons of bauxite per year.
Red mud, now more frequently termed bauxite residue, is an industrial waste generated during the processing of bauxite into alumina using the Bayer process. It is composed of various oxide compounds, including the iron oxides which give its red colour. Over 97% of the alumina produced globally is through the Bayer process; for every tonne (2,200 lb) of alumina produced, approximately 1 to 1.5 tonnes of red mud are also produced; the global average is 1.23. Annual production of alumina in 2023 was over 142 million tonnes resulting in the generation of approximately 170 million tonnes of red mud.
China Hongqiao Group Limited is a company founded in 1994 that specializes in the production of aluminium. Hongqiao is currently the second largest aluminium producer in the world after Chinalco. It is listed on the Hong Kong Stock Exchange with stock code 1378, and is incorporated in George Town, Cayman Islands.
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