It is worth starting with the fact that niobium is inextricably linked with a substance such as tantalum. This is despite the fact that these materials were not discovered at the same time.
What is niobium?
What is known today about such a substance as niobium? It is a chemical element, which is located in group 5 of the periodic table, with an atomic number of 41, and also an atomic mass of 92.9. Like many other metals, this substance is characterized by a gray-steel sheen.
One of the most important physical parameters of this metal is its refractoriness. It is thanks to this characteristic that the use of niobium has become widespread in many industries. The melting point of this substance is 2468 degrees Celsius, and the boiling point is 4927 degrees Celsius.
The chemical properties of this substance are also at a high level. It is characterized by a high level of resistance to negative temperatures, as well as to the effects of most aggressive environments.
Production
It is worth saying that the presence of ore, which contains the element Nb (niobium), is much greater than that which contains tantalum, but the problem is the scarcity of the content of the element itself in this ore.
Most often, in order to obtain this element, a thermal reduction process is carried out in which aluminum or silicon is involved. As a result of this operation, compounds of ferroniobium and ferrotanthaloniobium are obtained. It is worth noting that the metal version of this substance is obtained from the same ore, but a more sophisticated technology is used. Niobium crucibles and other materials obtained are characterized by very high performance characteristics.
Methods for producing niobium
Currently, one of the most developed areas for obtaining this material is aluminothermic, sodium thermal and carbothermic. The difference between these types also lies in the precursors that are used to restore niobium. Suppose that K2NbF7 is used in the sodium thermal method. But, for example, with the aluminothermic method, niobium pentoxide is used.
If we talk about the carbothermic method of production, then this technology involves the mixing of Nb with soot. This process should take place in high temperature and hydrogen environments. As a result of this operation, niobium carbide will be obtained. The second stage is that the hydrogen medium is replaced by a vacuum, and the temperature is maintained. At this moment, its oxide is added to niobium carbide and the metal itself is obtained.
It is important to note that niobium in ingots is quite common among the forms of metal produced. This product is intended for the production of metal-based alloys, as well as various other semi-finished products.
A staff of this material can also be produced, which is divided into several categories depending on the purity of the substance. Least of all impurities is contained in the headquarters marked NBSh-00. The NBSh-0 class is characterized by a higher presence of elements such as iron, titanium and silicon tantalum. The category that has the highest rate of impurities is NBSh-1. We can add that niobium ingots do not have such a classification.
Alternative manufacturing methods
Alternative methods include crucible-free electron beam zone melting. This process allows one to obtain Nb single crystals. Niobium crucibles are produced using this method. It relates to powder metallurgy. It is used in order to first obtain an alloy of this material, and then its pure sample. The presence of this method has led to the fact that advertisements for the purchase of niobium are quite common. This method allows using not the ore itself, which is rather difficult to extract, or concentrate from it, but secondary raw materials to obtain pure metal.
Another alternative production method is niobium rolling. It is worth noting that most of the various companies prefer to buy precisely rods, wire or sheet metal.
Rolled and foil
Foil from this material is a fairly common semi-finished product. It is the thinnest rolled sheet of this substance. This raw material is used for the production of certain products and parts. Niobium foil is obtained from pure raw materials by cold rolling of Nb ingots. The resulting products are characterized by such indicators as high resistance to corrosion, aggressive environment, as well as high temperature. Rolled niobium and its ingots also gives such characteristics as product resistance to wear, high ductility, good processability.
Products obtained in this way are most often used in such fields of activity as aircraft manufacturing, rocket science, medicine (surgery), radio engineering, electrical engineering, nuclear energy, and nuclear energy. Niobium foil is packaged in coils and stored in a dry, dry place, and also in a sheltered place from mechanical impact from the outside.
Application in electrodes and alloys
The use of niobium is very widespread. It can be used, like chromium and nickel, as a material that is part of the iron alloy used to make electrodes. Due to the fact that niobium, like tantalum, is able to form superhard carbide, it is often used for the production of superhard alloys. It can be added that they are currently trying to improve the properties of alloys based on non-ferrous metals using this material .
Since niobium is a raw material capable of creating carbide elements, it, like tantalum, is used as an alloying mixture in the production of steel. It is worth noting that for a long time the use of niobium as an impurity to tantalum was considered a negative effect. However, today the opinion has changed. It was found that Nb can act as a substitute for tantalum, and with great success, because due to the lower atomic mass, a smaller amount of substance can be used, while retaining all the old possibilities and effects of the product.
Application in electrical engineering
It is worth emphasizing that the use of niobium, like his brother tantalum, is possible in rectifiers, due to the fact that they have the property of unipolar conductivity, that is, these substances pass electric current in only one direction. It is possible to use this metal to create devices such as anodes that are used in powerful generators and amplification lamps.
It is very important to note that the use of niobium has reached nuclear power. In this industry, products from this substance are used as structural materials. This has become possible, since the presence of Nb in the parts makes them resistant to heat, and also gives them high qualities of chemical resistance.
The excellent physical characteristics of this metal have led to the fact that it is widely used in rocketry, in jet aircraft, in gas turbines.
Niobium production in Russia
If we talk about the reserves of this ore, then there are about 16 million tons. The largest field, occupying approximately 70% of the total volume, is located in Brazil. In Russia, about 25% of the reserves of this ore are located. This indicator is considered a significant part of all niobium reserves. The largest deposit of this substance is in Eastern Siberia, as well as in the Far East. Today, the company Lovozersky GOK is engaged in the extraction and production of this substance in the territory of the Russian Federation. You may notice that the company Stalmag was also involved in the production of niobium in Russia. She developed the Tatar deposit of this ore, but in 2010 it was closed.
You can also add that Solikamsk Magnesium Plant is engaged in the production of niobium oxide. They get it by processing loparite concentrate. This company produces between 400 and 450 tons of this substance, most of which is exported to countries such as the United States and Germany. Part of the remaining oxide goes to the Chepetsk Mechanical Plant, which produces both pure niobium and its alloys. Significant capacities are located there, which allow producing up to 100 tons of material per year.
Niobium metal and its value
Despite the fact that the scope of this substance is quite wide, the main purpose is the space and nuclear industries. For this reason, Nb refers to strategic materials.
The main parameters that affect the cost of niobium:
- purity of the alloy, a large number of impurities reduces the price;
- material delivery form;
- volumes of material supplied;
- location of the ore receiving point (different regions need a different amount of element, which means the price for it is different).
Sample list of prices for material in Moscow:
- NB-2 brand niobium costs between 420-450 rubles per kg;
- niobium shavings cost from 500 to 510 rubles per kg;
- the NBSh-00 brand stand costs from 490 to 500 rubles per kg.
It is worth noting that, despite the huge cost of this product, the demand for it is only increasing.