How to produce aluminum
Aluminum is present in our lives only about one and a half centuries, but in that short period of time to go from a decorative metal favorite jewelers to material allowing us to move faster, to live in warmth and comfort, to enjoy all the benefits of modernity and discover worlds around.
Aluminum - the most abundant metal on Earth, its share in the earth's crust up to 8, 8%. However, aluminum mines do not exist. Due to its chemical activity aluminum virtually does not occur in free form - only a few of its containing minerals and rocks are suitable for industrial production.
Today we will see how to produce aluminum on one of the largest aluminum smelters in the world.
Legend has it that once the Roman Emperor Tiberius (42 BCE -.... '37 BC) came from jeweler metal, unbreakable dinner plates, allegedly made from alumina (of Al2O3). Plate was very bright and shining like silver. By all indications, it should be of aluminum. In this case, the jeweler claimed that only he and the gods know how to get this metal from clay. Tiberius, fearing that the metal is easily accessible from the clay may devalue the gold and silver, just in case ordered the jeweler to cut off his head.
Only after almost 2000 years after Tiberius, in 1825, the Danish physicist Hans Christian Orsted received a few milligrams of aluminum metal, and in 1827 Friedrich Wohler was able to isolate the grains of aluminum, which, however, the air immediately covered with a thin film. Further Henri St. Clair Deville, which funded a study Napoleon III, invented the first method for industrial production of aluminum and has received the first ingot weighing about 7 kg. Deville began manufacturing aluminum factory Tissier brothers in Rouen. During the day, the factory produced two kilograms of aluminum. In 1857, a kilogram of this metal was worth 300 francs. In those years, a room for a month in Paris could be rented for 20 francs.
The beginning of the modern method of production of aluminum laid method, invented almost simultaneously in 1886 by Charles Hall in the United States and Paul Heroult in France. Since then, due to improvement of electrical, aluminum production was improved. Significant contribution to the development of production of alumina made by Russian scientists KI Bayer, DA Peniaky, A. Kuznetsov, E. Zhukovsky, AA Yakovkin and others.
Electrolyzers, working on environmental technologies Soderbergh:
The date of birth of the Russian aluminum industry is considered to be May 14, 1932, when the Volkhov plant the first batch of metal was obtained in the Leningrad region. A year later the first products released Dnieper aluminum plant in the Ukraine.
Using a vacuum ladle taken aluminum from the cell:
At the moment, the world leader in the aluminum industry, RUSAL is (Association "Russian Aluminum" company). Products are exported to customers in 70 countries. The company accounts for about 12.5% of global aluminum market 3.9 mln. Tons of aluminum per year. The combined company is present on 5 continents 100 000 people working in it in 17 countries around the world. Krasnoyarsk Aluminum Plant just belongs to RUSAL. KrAZ - the second largest aluminum producer in the world. Production capacity KrAza - 1 million tons of aluminum per year (about 24% of the Russian and 2.4% of the world production of aluminum)..
The production of aluminum is very energy intensive. Therefore, aluminum smelters mostly built in areas where there is free access to powerful sources of electricity. In our case, this is a source of Krasnoyarsk HPP, whose installed capacity of 6000 MW. Today it is the most powerful hydroelectric power plant in Russia (up until the Sayano-Shushenskaya hydroelectric power station is under construction). And the Krasnoyarsk aluminum plant consumes about 70% of the total volume of electricity produced by hydropower plants.
The pot in which aluminum is produced:
Aluminum made from alumina, which in turn is extracted mainly from bauxite (sometimes from nepheline ores), which stocks in the world virtually limitless. KrAZ we can only see the final stage of production. Process temperature reaches 955 degrees Celsius, well above the melting temperature of the metal - 660C.
Vacuum buckets can take at a time from 3 to 5 tons of hot metal:
The daily capacity of the plant - 2725 tons.
In the smelter put into operation only housing in Russia for high-purity aluminum production:
The purity of ultrapure metals - 99.996%. It is used in the production of computer hard drives, mobile phones and other electronic equipment, as well as in the aerospace and defense industries. The main supply of aluminum with KrAZ go to Asia, Japan, the United States.
The voltage applied to the electrolytic cell (device for electrolysis) is only 4.5 volts, but the current is huge - 174300 amperes:
If the housings receipt occurs Soderberg aluminum from alumina, the casing for the production of high purity aluminum (AVCH) starting material is more dirty aluminum. Simply stated, the technical aluminum extends secondary treatment, making it ultra pure. Performance of the cell AVCH - 600 kg / day.
KrAz is the only factory in the world that uses just three aluminum production technology - electrolyzers Soderberg AVCH for high purity electrolytic production of aluminum and with prebaked anodes.
Each plant building has gas treatment equipment installed in the first phase of ecological modernization:
claimed pollutant collection efficiency - 99.9%.
The production complex includes 3 KrAZ casting department. Below, photos from the casting department №3, which in addition to doing all the longest aluminum ingots in the world:
The mixer 100 tons of metal, which is the preparation of alloys. Mixer in fact - it's a big pot in which the ingredients are added in addition to the primary metal - alloying materials. The result is a high-grade aluminum alloy:
metal temperature in the mixer 800 degrees:
Pouring metal into the mixer:
The plant KrAZ confined to the production of high-tech products. For example, the factory is now developing the production of so-called slabs. They are widely demanded in the market of packaging materials needed for the production of body panels of cars. The casthouse Foundry Company operates a unique unit, which began to produce ingots double length - up to 11.5 meters. Constructed thereon alloys are now used in the production of foil. Moreover, it is bullion-champions. Such long aluminum bars did not let even a single plant of the world:
In 2012, the factory introduced a new production of the world car industry leaders. For example, Japanese concerns Toyota and Mitsubishi have ordered alloys to improve the performance characteristics of their cars. Metal have been proposed, which provides elements of the engine and wheels and strength, and ductility.
So produce aluminum.