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| Modern Technologies of Aluminum Production |
Bakhriddin Berdiyarov, Shokhrukh Khojiev, Shohruh Rakhmataliev, Maftuna Syunova, Nazokat Rasulova
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Abstract:
Despite the fact that aluminum is the most widespread metal on our planet, it cannot be found in its pure form on Earth. Due to the high chemical activity, aluminum atoms easily form compounds with other substances. In this case, "winged metal" cannot be obtained by melting ore in a furnace, as happens, for example, with iron. The process of obtaining aluminum is much more complicated and is based on the use of electricity of enormous power. Therefore, aluminum smelters are always built close to large sources of electricity - most often hydroelectric power plants that do not pollute the environment. But first things first. Metal production is divided into three main stages: the extraction of bauxite - an aluminum-containing ore, their processing into alumina - aluminum oxide, and, finally, the production of pure metal using the electrolysis process - the decomposition of aluminum oxide into its constituent parts under the influence of an electric current. From 4-5 tons of bauxite, 2 tons of alumina are obtained, from which 1 ton of aluminum is produced. There are several types of aluminum ores in the world, but bauxite is the main raw material for the production of this metal. It is a rock, consisting mainly of aluminum oxide with an admixture of other minerals. Bauxite is considered good quality if it contains more than 50% aluminum oxide. The world's total proven bauxite reserves are estimated at 18.6 billion tonnes. At the current level of production, this provides the need for aluminum for more than a hundred years. Bauxites can be very different from each other. In structure, they are hard and dense or loose and crumbly. In color - as a rule, brick-red, reddish or brown due to the admixture of iron oxide. With a low iron content, bauxites are white or gray. But sometimes there are ores of yellow, dark green color and even variegated - with blue, red-violet or black veins. About 90% of the world's bauxite reserves are concentrated in the countries of the tropical and subtropical belts - of which 73% are in five countries: Guinea, Brazil, Jamaica, Australia and India. In Guinea, bauxites are the most - 5.3 billion tons (28.4%), while they are of high quality, contain a minimum amount of impurities and lie almost on the surface.
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