The many faces of molybdenum: where it is used, properties, biological role in the human body. Application of molybdenum and its properties

Due to its properties, the use of molybdenum in industry is widespread in Russia and the world. Metallurgy, aviation industry, mechanical engineering, agriculture - this is not the whole list where this strategic metal is used. It is in such demand that the price of molybdenum is steadily increasing year after year.

Material characteristics

Physical properties. Molybdenum is a gray rare earth metal similar in appearance to lead. Melting point 2619 ºС.
It is distinguished by increased plasticity. Young's modulus is 336 GPa, which is 1.5 times more than steel. The density is 10.2 g/cm3. Tungsten is considered the most heat-resistant metal. But with regards to specific heat resistance at temperatures up to 1400 ºС, molybdenum has no competitors. Molybdenum has a low coefficient of linear expansion. When the temperature changes by 1000 ºС, its size will increase by only 0.0049 mm.

Thermal conductivity is 300 W/m K. Electrical resistance is 5.6 μΩ cm. After preliminary mechanical and thermal treatments, the strength of the metal can be 20-23 kg/mm2. Has paramagnetic properties.

Among the disadvantages, we note low plasticity at temperatures below -30 ºС.

Chemical properties. Molybdenum is completely resistant to attack environment under normal atmospheric conditions. The oxidation process begins at 420 ºC, forming a low-hardness compound, molybdenum oxide.

Molybdenum is inert to hydrogen at temperatures up to 2620 ºС. Neutral to such elements as carbon, fluorine, silicon, nitrogen, sulfur. Molybdenum does not enter into chemical reactions with the main types of acids: hydrochloric, sulfuric, nitric, fluoric.

Technological properties. Under room temperature conditions, a molybdenum circle with a radius of 5 mm can be tied into a knot without using special equipment or be rolled out to a thickness of 0.1 mm. This malleability of the metal helps to obtain different types profile rolled products.

Molybdenum can be easily processed by cutting, provided that a sulfur-based cutting fluid is used.

Molybdenum does not stand out for the quality of its welds. Belongs to group 3 weldability. The welding process is carried out using the arc method. To give welded joints greater ductility, the contact zone must be in a protective gas environment. Preference here is given to helium or argon.

Biological properties. Molybdenum is contained in the human body in the range of 8-10 mg. First of all, it affects the course of anabolic processes. Enhances the effects of vitamin C, thereby strengthening the immune system. Molybdenum is a copper regulator and prevents its accumulation in the blood.

Molybdenum alloys have a characteristic chemical composition - a low percentage of alloying elements. Only two-component solid solutions have a significant percentage of tungsten in their composition (up to 50%).

The main domestic brands of molybdenum alloy are:

• Molybdenum alloy TsM-2A. Alloying additives are titanium (0.07-03%) and zirconium (0.07-0.15%). In addition to these elements, it may include carbide phases (up to 0.004%). The tensile strength is 30 kg/mm2. It drops significantly after passing the temperature threshold of 1200 C. The main advantages of the alloy are manufacturability and ductility, which make it possible to obtain industrial semi-finished products from it.
• Molybdenum alloy VM-1 does not differ significantly from the alloy described above. It has similar indicators of both chemical and mechanical properties.
• Molybdenum VM-2 contains a higher percentage of zirconium, making it more heat-resistant. This allows it to withstand ambient temperatures of 1300-1400 C. It has a tensile strength of 48 kg/mm2, 1.6 times higher than that of TsM-2A.
• Additional alloying of the VM-3 molybdenum alloy with titanium (1.3%), zirconium (0.6%), and niobium (1.8%) leads to a further increase in heat resistance. Withstands loads of up to 27 kg/mm2 at temperatures up to 1360 C. However, VM-3 has a reduced level of ductility. This makes it less technologically advanced and limits its use in production.

Application options for molybdenum

As a heat- and corrosion-resistant material, it is used in the production of the most loaded parts of mechanisms and structures of various types of industry. Among its main purposes it should be noted:

• Application in the aviation industry in the manufacture of various components of turboprop jet engines: air intakes, turbine blades, etc.
• The rocket and space industry uses molybdenum in production individual parts aircraft components: nose cones, heat reflectors, rudders, honeycomb panels, skin, etc. This happens due to the relationship between heat resistance and density. Although molybdenum is inferior in absolute heat resistance to tungsten, it is ahead of it in specific resistance. Therefore, at temperatures below 1350 it is more profitable to use molybdenum, because the weight of the structure is significantly reduced.
• Use in metallurgy as an alloying additive. Molybdenum refines the grain structure of steel, thereby strengthening it. In addition, there is an increase in corrosion resistance, hardenability and hardness. Adding 0.3% molybdenum to steel increases its strength by 3 times.
• In electrical engineering, it is used in the manufacture of tungsten filament holders in incandescent lamps. This use is associated with molybdenum’s properties of maintaining linear dimensions at elevated temperatures.
• In mechanical engineering, molybdenum is used as a material for sleeves of sliding bearings and balls of rolling bearings. Tips of cutting tools: countersinks, drills, turning tools, milling cutters.
• Molybdenum electrodes are used in electric furnaces to melt glass, due to the fact that the metal does not enter into chemical reactions with silicon oxide.
• Molybdenum sulfides serve as high-temperature lubricants in critical friction components.
• In heating engineering it is used as a material for heaters and thermal insulation of vacuum furnaces.
• In medicine, molybdenum is a raw material in the production of technetium, which serves as a means of diagnosing malignant tumors.
• IN agriculture Molybdenum is added to fertilizers. Molybdenum has been proven to increase plant growth.

It is even added to engine oil due to its anti-corrosion properties.

Chemistry is the foundation of our life. All household items consist of compounds of elements of the periodic table. Every minute the human body undergoes complex transformations in which chemical substances participate. This article will talk about a metal such as molybdenum: where it is used, its properties and role in the human body.

Let's go deeper into history

Minerals containing molybdenum were known back in Ancient Greece. These natural compounds had a structure similar to graphite. Therefore, they were often used along with it to create styluses. Molybdenite MoS₂ had a gray-green tint when written on paper. For its characteristic shine, it was given the name molybdaena - “like lead”.

Karl Wilhelm Scheele conducted research through which he synthesized MoO₃ trioxide, but due to the lack of an appropriate furnace, he was unable to isolate the metal in its pure form. Jöns Jakob Berzelius managed to obtain molybdenum in 1817 by reducing the oxide not with coal, but with hydrogen. The synthesized chemical element was carefully studied and described in the works of the scientist.

Physical properties

Due to the refractoriness of molybdenum, it is used to create molds for casting parts from copper, aluminum and zinc. The high strength of the metal allows processes to be carried out under high pressure.

Rolling and stamping, application

From the blanks obtained by smelting the powder, rolled products are created - rods and wire. They consist of pure metal called molybdenum. Where are these products used? It is most often used in the manufacture of thermocouples, which are used to measure temperatures above 2000 ⁰C. Hooks and cores for winding tungsten filament in an incandescent lamp are also made from molybdenum wire. The cathode inputs and focusing electrodes in generator lamps must be reliable and meet the requirements of high metal refractoriness. Rolled molybdenum is excellent for these purposes.

Rods and plates are used instead of electrodes in high temperature melting furnaces. They must be in a special environment consisting of argon, hydrogen or vacuum. Due to the fact that molybdenum does not enter into chemical reactions with glass, it is used for the manufacture of melting furnace parts.

Application in other industries

Molybdenum has found application in the oil industry. There it is used as a catalyst capable of purifying products from sulfur impurities. Lubricants are made based on aluminum disulfide. They stabilize the operation of various devices and protect surfaces from mechanical stress at high temperatures. This lubricant also has anti-corrosion properties.

In the manufacture of paints and varnishes, where molybdenum and its oxides are used, persistent pigments of yellow-orange tones are obtained. The synthesis of artificial fibers also does not take place without this substance. To increase the nitrogen content in the soil, microfertilizers that include molybdenum are used.

The role of molybdenum in the body

Molybdenum plays a significant role in the human body. It is involved in hemoglobin synthesis, nitrogen and purine metabolism. Responsible for the absorption of iron and vitamin C and is a powerful antioxidant. The microelement has an oncoprotective and rejuvenating effect.

Foods rich in molybdenum are legumes, cereals, and leafy vegetables. The required amount of microelement enters the body daily if you eat properly. Its deficiency can be compensated using mineral complexes.

Three scientists were involved in the discovery of molybdenum: first, the Swede Karl Scheele obtained the oxide MoO 3 from molybdic acid (1778), then the Frenchman P. Ghelm reduced it with coal and obtained a metal with impurities (1782), and after J. Berzelius achieved pure molybdenum as a result of the combination of oxide and hydrogen.

Molybdenum is mined all over the planet, since it is relatively evenly distributed both throughout the earth's crust and in the waters of the oceans. This element is found in both coal and oil, but its largest amount is in feldspars.

Molybdenum: physical properties

Externally, molybdenum is a metal with a traditional light gray color. It belongs to the category of refractory, but the purer it becomes softer. Main characteristics of molybdenum:

• density (no.) – 10.22 g/cm³
• melting point – 2620°C (2890 K)
• boiling point – 4639°C (4885 K)
• thermal conductivity at 300 K – 138 W/(m K)

Molybdenum: chemical properties

The element Mo is stable up to 400°C, after which it oxidizes. To date, several molybdenum oxides have been obtained, including MoO 3 trioxide, molybdenum (IV) oxide MoO 2, etc. There are also carbides - Mo 2 C and MoC, which are crystalline high-melting substances.


Molybdenum is present in more than 20 types of minerals. The most common can be considered:

• >molybdenite - MoS 2
• molybdite - Fe(MoO 4) 3 nH 2 O
• wulfenite - PbMoO 4
• powellite - SaMoO 4

Molybdenum: where is it used?

The widespread production of molybdenum in the world is determined, first of all, by the needs of the global metallurgy. This metal acts as an alloying component for most corrosion-resistant and heat-resistant steels. In addition, it is indispensable for giving the metal increased strength characteristics and increased toughness. Manufacturers of light bulbs and high-temperature furnaces cannot do without molybdenum. The chemical industry uses Mo and its compounds as catalysts for chemical reactions, pigments for dyes, etc.


Another area of ​​application for molybdenum is medicine: pure Mo helps doctors diagnose cancer. The same element can be found in the material for mirrors of high-power gas-dynamic lasers.

Biological role

Molybdenum is not a common element, but it is present in every human body. Moreover, a lack of Mo in the human body can disrupt the most important biological processes, thereby causing serious illness. It is known that the highest concentration of molybdenum is present in the following products: milk, liver, cereals, legumes, and leafy vegetables.

Properties of molybdenum very useful to people. After all molybdenum, added to alloys, increases their resistance to chipping. Knives and other cutting objects, as well as drills, are made exclusively from steels with an admixture of rare metal. Interestingly, the technology was forgotten for centuries. Until the 19th century, scientists tried to unravel the secret of Japanese samurai swords, forged in the Middle Ages. At the turn of the 20th century, physicists and chemists finally discovered the presence of molybdenum in gun steel. It was he who made swords extremely strong and durable.

Molybdenum formula Mo.Element is not found in its pure form. The molybdenum content in minerals is evenly dispersed in the earth's crust, which makes mining impractical. Sometimes only accumulations of molybdenite ore are found. Its largest deposit is being developed in the US state of Colorado.

To ensure that the guns do not chip, a 6% addition of molybdenum to the alloy is required. This element is also known for making parts more resistant to high temperatures. Many factory furnaces and other containers that generate, for example, steam are made from molybdenum alloys. They are also used in the automotive industry for camshafts and valves.

Fittings and pipes require molybdenum “infusions” to improve anti-corrosion properties. Compositions with metal are the only ones suitable for the production of aircraft. Passenger airliners of our time are of impressive size. Steel without an “additive” does not stretch to such parameters only if the wall is thick. Aircraft require thin sheets. These can only be obtained from alloys with molybdenum.

At temperatures from 600 to 900 degrees Celsius molybdenum metal actively oxidizes and forms molybdenum oxide. It absorbs oxygen when neon and argon are passed over its surface. This is how people purify these noble gases from excess impurities.

Without molybdenum there would be different fur coats and sheepskin coats. Metal is added to tanning mixtures. Salts of molybdic acid are used for them. Without the recipe, it would not have been possible to obtain such soft and elastic skin.

Even oil industry based on molybdenum. It is necessary for cracking organic matter. This is the name given to the process of oil splitting.

The mineral molybdenite is revered in the field of education. It, like graphite, is used for pencil leads. The mineral is very soft. Its structure is scaly. With the slightest pressure, the scales separate, remaining on the paper in the form of letters and other symbols.

People of art also turn to metal with a leaden sheen. The element is added to coloring compositions, in particular enamel. With molybdenum in the composition, it is simpler, distributed in a thinner layer over the surface being treated, and adheres better to it.

Jewelers have learned to replace platinum with molybdenum. The metal is similar in appearance to a noble element and does not oxidize at ordinary temperatures. Those who make jewelry are going to take into account the discovery made by US physicists.

They did not stop at the external similarity of a simple element with a precious one. Scientists have changed the lattice of molybdenum, bringing it as close as possible to platinum. For the experiments, we needed a nickel compound with the hero of the article and nitrogen. In the presence of this gas, the molecular lattice of molybdenum expanded, and the electron density in it increased. These are the parameters that distinguish platinum.

The Americans experimented in hopes of creating new electrocatalysts needed in the energy sector. Now parts are made of platinum, which is very expensive. The opening will reduce the costs of industrialists, and, consequently, consumers. Jewelers will be able not only to replace platinum, but in fact, to create its artificial analogue.

The word "molybdenum" is Greek. In the ancient language the concept means “lead”. Its shine is similar to the glow of metal No. 42. So I called it Swedish chemist Scheele molybdenum molybdenum. The scientist isolated it in the form of an oxide in 1778. Another chemist, Scheele’s compatriot, Gjelm, was able to obtain pure metal. This happened in 1782. It was then that molybdenum oxide was reduced by carbon, which led to the appearance of a metal with a lead luster without any impurities.

Russia has 10 deposits of element No. 42. Seven mines are being developed on an industrial scale. Metal is also mined in neighboring China. 7 provinces of the Celestial Empire are proud of molybdenum: Shanxi, Liaoning, Hebei, Jilin, Jiangxi, Shandong and Henan. There are deposits in Canada. The United States is inferior in the number of deposits but, as already indicated, ranks first in reserves of molybdenum, located in Colorado.

Molybdenum is needed not only by industrialists, but also by the body. Metal is a constant component of living beings. Element No. 42 regulates metabolic processes, retains fluoride in the organs, thereby helping teeth remain strong. Without molybdenum, cells are unable to grow or develop. The metal promotes the synthesis of ascorbic acid and ensures normal tissue respiration. There will be no breathing, there will be no life. By the way, this is precisely why it is not on Mars, scientists suggest. They claim that life did not originate on the red planet because there was no molybdenum.

The body needs 75-300 microkilograms per day. Both smaller and larger doses are harmful. A storehouse of molybdenum is leafy vegetables, grains, legumes, sunflower seeds and garlic. So, the latter not only protects against colds and improves immunity. Garlic also helps produce red herbal cells, triggers cell respiration and more.