Aluminum ore: deposits, mining
In modern industry, aluminum oreis the most demanded raw material. The rapid development of science and technology has made it possible to expand the scope of its application. What is aluminum ore and where it is mined is described in this article.
The industrial value of aluminum
Aluminum is considered the most commonmetal. According to the number of deposits in the earth's crust, it occupies the third place. Aluminum is known to everyone also as an element in the periodic table, which refers to light metals.
Aluminum ore is a natural raw material, fromwhich receive this metal. Basically, it is extracted from bauxites, which contain aluminum oxides (alumina) in the largest amount - from 28 to 80%. Other rocks - alunite, nepheline and nepheline-apatite are also used as raw materials for aluminum production, but they are of poor quality and contain significantly less alumina.
In non-ferrous metallurgy, aluminum occupies the firsta place. The fact is that due to its characteristics it is used in many industries. So, this metal is used in transport engineering, packaging production, construction, for manufacturing various consumer goods. Also, aluminum is widely used in electrical engineering.
To understand the importance of aluminum forhumanity, it is enough to take a closer look at the everyday things that we use day to day. Very many household items are made of aluminum: parts for electrical appliances (refrigerator, washing machine, etc.), dishes, sports equipment, souvenirs, interior items. Aluminum is often used for the production of various types of packaging and packaging. For example, cans or disposable foil containers.
Types of aluminum ores
Aluminum is contained in more than 250 minerals. Of these, bauxite, nepheline and alunite are the most valuable for industry. Let us dwell on them in more detail.
In nature, aluminum is not found in pure form.Basically it is obtained from aluminum ore - bauxite. It is a mineral, which for the most part consists of aluminum hydroxides, as well as iron oxides and silicon. Due to the high content of alumina (from 40 to 60%), bauxites are used as raw materials for the production of aluminum.
Physical properties of aluminum ore:
- opaque mineral of red and gray in various shades;
- hardness of the strongest samples is 6 on the mineralogical scale;
- The density of bauxite, depending on the chemical composition, varies between 2900-3500 kg / m³.
Deposits of bauxite ore are concentrated in the equatorial and tropical belt of the earth. More ancient deposits are located on the territory of Russia.
How bauxite aluminum ore is formed
Bauxite is formed from a single-water alumina hydrate, boehmite and diaspora, a three-hydrate hydrargillite hydrate and accompanying minerals of hydroxide and iron oxide.
Depending on the composition of nature-forming elements, three groups of bauxite ores are distinguished:
- Monohydrate bauxites - contain alumina in a single-water form.
- Trihydrate - such minerals are composed of alumina in a three-water form.
- Mixed - this group includes a combination of previous aluminum ores.
Deposits of raw materials are formed due to the weathering of acidic, alkaline, and sometimes basic rocks or as a result of the gradual precipitation of large amounts of alumina on the sea and lake bottom.
This type of deposit contains up to 40% of aluminum oxide.Alunite ore is formed in the water basin and coastal zones in conditions of intense hydrothermal and volcanic activity. An example of such deposits is Lake Zaglinskoye in the Lesser Caucasus.
The rock is porous. It mainly consists of kaolinites and hydromica. Industrial interest is an ore with an alunite content of more than 50%.
This is an aluminum ore of magmatic origin.It is a full-crystalline alkaline rock. Depending on the composition and technological features of processing, several types of nepheline ore are distinguished:
- the first grade is 60-90% nepheline; it contains more than 25% of alumina; processing is carried out by the sintering method;
- second grade - 40-60% nepheline, the amount of alumina is slightly lower - 22-25%; during processing, enrichment is required;
- third grade - nepheline minerals, which do not represent any industrial value.
World production of aluminum ores
For the first time, aluminum ore was mined in the first halfXIX century in the south-east of France, near the town of Box. Hence the name of bauxite. At first this industry developed at a slow pace. But when mankind appreciated what kind of aluminum ore is useful for production, the scope of aluminum has expanded significantly. Many countries began to search deposits on their territories. Thus, world production of aluminum ores began to increase gradually. This is confirmed by figures. So, if in 1913 the world volume of extracted ore was 540 thousand tons, then in 2014 - more than 180 million tons.
Also gradually the number of countries,extracting aluminum ore. To date, there are about 30. But over the past 100 years, leading countries and regions have been constantly changing. Thus, at the beginning of the 20th century, the world leaders in the extraction of aluminum ore and its production were North America and Western Europe. These two regions accounted for about 98% of global production. After several decades, the leaders in the quantitative indicators of the aluminum industry were the countries of Eastern Europe, Latin America and the Soviet Union. And already in the 1950-1960-ies the leader in terms of production was Latin America. And in the 1980-1990's. there was a rapid breakthrough in the aluminum industry in Australia and Africa. In the current world trend, the main countries-leaders in the extraction of aluminum are Australia, Brazil, China, Guinea, Jamaica, India, Russia, Suriname, Venezuela and Greece.
Ore deposits in Russia
By the volume of extraction of aluminum ores, Russia occupiesseventh in the world ranking. Although aluminum ore deposits in Russia provide the country with a large amount of metal, it is not enough to fully provide the industry. Therefore, the state is forced to buy bauxite in other countries.
A total of 50 ore deposits are located on the territory of Russia. This number includes both the places where the mineral is mined and the deposits not yet developed.
Most of the ore reserves are inEuropean part of the country. Here they are located in Sverdlovsk, Arkhangelsk, Belgorod region, in the Republic of Komi. All these regions contain 70% of all the explored ore reserves of the country.
Aluminum ores in Russia are still mined inold bauxite deposits. Such areas include the Radynskoye field in the Leningrad region. Also, due to a shortage of raw materials, Russia uses other aluminum ores whose deposits are characterized by the worst quality of mineral deposits. But they are still suitable for industrial purposes. Thus, in Russia, nepheline ores are mined in large quantities, which also make it possible to obtain aluminum.