Chemical properties of titanium. General characteristics. Discovery history. Pros and cons

Titanium occupies the 4th place in terms of distribution in production, but an effective technology for its extraction was developed only in the 40s of the last century. It is a silver-colored metal, characterized by a low specific gravity and unique characteristics. To analyze the degree of distribution in industry and other areas, it is necessary to voice the properties of titanium and the scope of its alloys.

Main characteristics

The metal has a low specific gravity - only 4.5 g/cm³. Anti-corrosion properties are due to a stable oxide film formed on the surface. Due to this quality, titanium does not change its properties during prolonged exposure to water, hydrochloric acid. Damaged areas do not occur due to stress, which is the main problem of steel.

In its pure form, titanium has the following qualities and characteristics:

• nominal melting point — 1660°С;
• under thermal influence +3 227 ° С boils;
• tensile strength - up to 450 MPa;
• characterized by a low elasticity index - up to 110.25 GPa;
• on the HB scale, the hardness is 103;
• the yield strength is one of the most optimal among metals - up to 380 MPa;
• thermal conductivity of pure titanium without additives - 16.791 W / m * C;
• minimum coefficient of thermal expansion;
• this element is a paramagnet.

For comparison, the strength of this material is 2 times that of pure iron and 4 times that of aluminum. Titanium also has two polymorphic phases - low-temperature and high-temperature.

For industrial needs, pure titanium is not used because of its high cost and required performance. To increase the rigidity, oxides, hybrids and nitrides are added to the composition. Rarely change the characteristics of the material to improve corrosion resistance. The main types of additives for obtaining alloys: steel, nickel, aluminum. In some cases, it performs the functions of an additional component.

Areas of use

Due to its low specific gravity and strength parameters, titanium is widely used in the aviation and space industries. It is used as the main structural material in its pure form. In special cases, by reducing the heat resistance, cheaper alloys are made. At the same time, its corrosion resistance and mechanical strength remain unchanged.

In addition, the material with titanium additives has found application in the following areas:

• Chemical industry. Its resistance to almost all aggressive media, except for organic acids, makes it possible to manufacture complex equipment with good indicators of maintenance-free service life.
• Vehicle production. The reason is the low specific gravity and mechanical strength. Frames or load-bearing structural elements are made from it.
• The medicine. For special purposes, a special alloy nitinol (titanium and nickel) is used. Its distinguishing feature is shape memory. To reduce the burden on patients and minimize the likelihood of negative effects on the body, many medical splints and similar devices are made of titanium.
• In industry, metal is used for the manufacture of cases and individual elements of equipment.
• Titanium jewelry has a unique look and feel.

In most cases, the material is processed in the factory. But there are a number of exceptions - knowing the properties of this material, part of the work to change the appearance of the product and its characteristics can be performed in the home workshop.

Processing Features

To give the product the desired shape, it is necessary to use special equipment - a lathe and a milling machine. Manual cutting or milling of titanium is not possible due to its hardness. In addition to the choice of power and other characteristics of the equipment, it is necessary to choose the right cutting tools: milling cutters, cutters, reamers, drills, etc.

This takes into account the following nuances:

• Titanium shavings are highly flammable. It is necessary to force cooling the surface of the part and work at minimum speeds.
• The bending of the product is carried out only after the preliminary heating of the surface. Otherwise, cracks are likely to appear.
• Welding. Special conditions must be observed.

Titanium is a unique material with good performance and technical properties. But for its processing, you should know the specifics of the technology, and most importantly, safety precautions.

It is one of the most important structural materials, as it combines strength, hardness and lightness. However, other properties of the metal are very specific, which makes the process of obtaining a substance difficult and expensive. And today we will consider the world technology for the production of titanium, briefly mention and.

There is metal in two modifications.

• α-Ti- exists up to a temperature of 883 C, has a dense hexagonal lattice.
• β-Ti– has a body-centered cubic lattice.

The transition is carried out with a very small change in density, since the latter gradually decreases with heating.

• During the operation of titanium products, in most cases, they deal with the α-phase. But when melting and manufacturing alloys, metallurgists work with β-modification.
• The second feature of the material is anisotropy. The coefficient of elasticity and the magnetic susceptibility of a substance depends on the direction, and the difference is quite noticeable.
• The third feature is the dependence of metal properties on purity. Ordinary technical titanium is not suitable, for example, for use in rocket science, because it loses its heat resistance due to impurities. In this industry, only extremely pure substances are used.

This video will tell about the composition of titanium:

Titanium production

The use of metal began only in the 50s of the last century. Its extraction and production is a complex process, due to which this relatively common element was classified as conditionally rare. And then we will consider the technology, equipment of titanium production workshops.

Raw material

Titanium is the 7th most abundant in nature. Most often these are oxides, titanates and titanosilicates. The maximum amount of the substance is contained in dioxides - 94–99%.

• Rutile- the most stable modification, is a bluish, brownish-yellow, red mineral.
• Anataz- a rather rare mineral, at a temperature of 800-900 C it turns into rutile.
• Brookite- a crystal of the rhombic system, at 650 C it irreversibly transforms into rutile with a decrease in volume.

• Metal compounds with iron are more common - ilmenite(up to 52.8% titanium). These are geikilite, pyrophanite, krichton - the chemical composition of ilmenite is very complex and varies widely.
• Used for industrial purposes, the result of weathering ilmenite - leucoxene. A rather complex chemical reaction takes place here, in which part of the iron is removed from the ilmenite lattice. As a result, the volume of titanium in the ore increases - up to 60%.
• Also, ore is used, where the metal is not associated with ferrous iron, as in ilmenite, but acts in the form of ferrous oxide titanate - this arizonite, pseudobrookite.

The deposits of ilmenite, rutile and titanomagnetite are of the greatest importance. They are divided into 3 groups:

• igneous- are associated with areas of distribution of ultrabasic and basic rocks, in other words, with the distribution of magma. Most often these are ilmenite, titanomagnetite ilmenite-hematite ores;
• exogenous deposits- placer and residual, alluvial, alluvial-lake deposits of ilmenite and rutile. As well as coastal-marine placers, titanium, anatase ores in weathering crusts. Coastal-marine placers are of the greatest importance;
• metamorphosed deposits– sandstones with leucoxene, ilmenite-magnetite ores, solid and disseminated.

Exogenous deposits - residual or alluvial, are developed by an open method. For this, dredges and excavators are used.

The development of primary deposits is associated with the sinking of mines. The resulting ore is crushed and enriched on site. Apply gravitational enrichment, flotation, magnetic separation.

Titanium slag can be used as a raw material. It contains up to 85% metal dioxide.

Production technology

The process of producing metal from ilmenite ores consists of several stages:

• reduction melting to obtain titanium slag;
• slag chlorination;
• metal production by recovery;
• titanium refining - as a rule, is carried out in order to improve the properties of the product.

The process is complex, multi-stage and expensive. As a result, a fairly affordable metal is very expensive to manufacture.

This video will tell about the production of titanium:

Receiving slag

Ilmenite is an association of titanium oxide with ferrous iron. Therefore, the purpose of the first stage of production is to separate the dioxide from the oxides of iron. For this, iron oxides are reduced.

The process is carried out in electric arc furnaces. Ilmenite concentrate is loaded into the furnace, then a reducing agent is introduced - charcoal, anthracite, coke, and heated to 1650 C. In this case, iron is reduced from oxide. Cast iron is obtained from reduced and carburized iron, and titanium oxide passes into slag. The latter eventually contains 82–90% titanium.

Cast iron and slag are poured into separate moulds. Cast iron is used in metallurgical production.

Slag chlorination

The purpose of the process is to obtain metal tetrachloride, for further use. It is impossible to directly chlorinate the ilmenite concentrate, due to the formation of a large amount of ferric chloride - the compound destroys the equipment very quickly. Therefore, it is impossible to do without the stage of preliminary removal of iron oxide. Chlorination is carried out in mine or salt chlorinators. The process is somewhat different.

• Mine chlorinator- a lined cylindrical structure up to 10 m high and up to 2 m in diameter. From above, briquettes from crushed slag are placed in the chlorinator, and gas from magnesium electrolyzers containing 65–70% chlorine is fed through tuyeres. The reaction between titanium slag and chlorine occurs with the release of heat, which provides the required temperature for the process. Gaseous titanium tetrachloride is withdrawn through the top, and the remaining slag is continuously removed from the bottom.
• Salt chlorinator, a chamber lined with chamotte and half filled with spent magnesium electrolytic electrolyte. The melt contains metal chlorides - sodium, potassium, magnesium and calcium. Crushed titanium slag and coke are fed into the melt from above, and chlorine is injected from below. Since the chlorination reaction is exothermic, the temperature regime is maintained by the process itself.

Titanium tetrachloride is purified several times. The gas may contain carbon dioxide, carbon monoxide, and other impurities, so cleaning is carried out in several stages.

The spent electrolyte is periodically replaced.

Receiving metal

The metal is reduced from tetrachloride with magnesium or sodium. The reduction occurs with the release of heat, which allows the reaction to be carried out without additional heating.

Electric resistance furnaces are used for recovery. First, a sealed flask made of chromium alloys 2–3 m high is placed in the chamber. After the container is heated to +750 C, magnesium is introduced into it. And then serves titanium tetrachloride. The feed is adjustable.

1 recovery cycle lasts 30–50 hours, so that the temperature does not rise above 800–900 C, the retort is blown with air. As a result, from 1 to 4 tons of spongy mass is obtained - the metal is deposited in the form of crumbs, which are sintered into a porous mass. Liquid magnesium chloride is periodically drained.

The porous mass absorbs quite a lot of magnesium chloride. Therefore, after reduction, vacuum distillation is carried out. To do this, the retort is heated to 1000 C, a vacuum is created in it and kept for 30–50 hours. During this time, impurities evaporate.

Reduction with sodium proceeds in much the same way. The difference is present only in the last stage. To remove impurities of sodium chloride, the titanium sponge is crushed and the salt is leached out of it with plain water.

Refining

The technical titanium obtained in the manner described above is quite suitable for the production of equipment and containers for the chemical industry. However, for areas where high heat resistance and uniformity of properties are required, the metal is not suitable. In this case, resort to refining.

Refining is carried out in a thermostat, where the temperature is maintained at 100–200 C. A retort with a titanium sponge is placed in the chamber, and then, using a special device, a capsule with iodine is broken in a closed chamber. Iodine reacts with metal to form titanium iodide.

Titanium wires are stretched in the retort, through which an electric current is passed. The wire is heated to 1300-1400 C, the resulting iodide decomposes on the wire, forming crystals of the purest titanium. Iodine is released, reacts. With a new portion of titanium sponge, the process continues until the metal is exhausted. The production is stopped when, due to the growth of titanium, the wire diameter becomes 25–30 mm. In one such apparatus, 10 kg of metal can be obtained with a share of 99.9–99.99%.

If it is necessary to obtain malleable metal in ingots, they proceed differently. To do this, titanium sponge is melted in a vacuum arc furnace, since the metal actively absorbs gases at high temperatures. The consumable electrode is made from titanium waste and a sponge. Liquid metal solidifies in the apparatus in a water-cooled mold.

The melt is usually repeated twice to improve the quality of the ingots.

Due to the characteristics of the substance - reactions with oxygen, nitrogen and absorption of gases, the production of all titanium alloys is also possible only in electric arc vacuum furnaces.

Read about Russia and other titanium producing countries below.

Popular manufacturers

The titanium production market is rather closed. As a rule, countries that produce a large amount of metal are themselves its consumers.

In Russia, the largest and perhaps the only company involved in the production of titanium is VSMPO-Avisma. It is considered the largest metal manufacturer, but this is not entirely true. The company produces one-fifth of titanium, but its global consumption looks different: about 5% is spent on products and alloy preparation, and 95% is used to produce dioxide.

So, the production of titanium in the world by country:

• China is the leading producing country. The country has the maximum reserves of titanium ores. Of the 18 known titanium sponge factories, 9 are located in China.
• Japan is in second place. Interestingly, only 2-3% of the metal goes to the aerospace sector in the country, and the rest is used in the chemical industry.
• The third place in the world in titanium production is occupied by Russia and its numerous factories. Then comes Kazakhstan.
• The United States is the next producing country on the list, consumes titanium in the traditional way: 60-75% of titanium is used by the aerospace industry.

Titanium production is a technologically complex, expensive and lengthy process. However, the demand for this material is so great that a significant increase in metal production is predicted.

This video will tell you how titanium is cut at one of the production facilities in Russia:

The combination of strength and lightness in one substance is a valuable parameter so much that other qualities and features of the material can be completely ignored. expensive in , resistant to temperatures only in ultrapure form, difficult to use, but all this turns out to be secondary compared to the combination of low weight and high strength.

This article will tell you about the use of titanium in military aviation, industry, medicine, aircraft manufacturing, for the manufacture of jewelry, titanium alloys, and household applications.

The scope of the metal would be much wider if it were not for the high cost of its production. Because of this, titanium is used only in those areas where the use of such an expensive substance is economically justified. It determines the use not only strength and lightness, but also resistance to corrosion, comparable to the resistance of precious metals and durability.

The properties of the metal are unusually strongly dependent on purity, so the use of technical and pure titanium are considered as 2 separate issues.

About what properties titanium is so widely used in industry, this video will tell:

technical metal

Technical titanium may contain a variety of impurities that do not affect the chemical properties of the substance, but have an impact on the physical. Technical titanium loses such a valuable quality as heat resistance and the ability to work at temperatures above 500-600 C. But its corrosion resistance does not decrease in any way.

• This is the reason for its use - in the chemical industry and in any other area where it is necessary to ensure the resistance of products in aggressive environments. Titanium is used to make storage tanks, fittings, parts of reactors, pipelines and pumps, the purpose of which is the movement of inorganic and organic acids and bases. Most titanium alloys have the same properties.
• Light weight, together with corrosion resistance, provides another application - in the manufacture of transport equipment, in particular, railway transport. The use of titanium sheets and rods in the manufacture of cars and trains makes it possible to reduce the mass of trains, and, therefore, to reduce the size of axle boxes and necks, making traction more efficient.

In ordinary cars, exhaust systems and coil springs are made from titanium. In racing cars, titanium drive units can significantly lighten the car and improve its properties.

• Titanium is indispensable in the production of armored vehicles: this is where the combination of strength and lightness is decisive.
• High corrosion resistance and lightness make the material attractive for naval affairs as well. Titanium is used in the manufacture of thin-walled pipes and heat exchangers, submarine exhaust mufflers, valves, propellers, turbine components, and so on.

Titanium products (photo)

pure metal

Pure metal exhibits very high heat resistance, the ability to work under high load and high temperature. And, given its low weight, the use of metal in the rocket and aircraft industry is obvious.

• Metal and its alloys are used to make fasteners, trim, chassis parts, a power set, and so on. In addition, the material is used in the construction of aircraft engines, which makes it possible to reduce their weight by 10–25%.
• Rockets when passing through the dense layers of the atmosphere experience monstrous loads. The use of titanium and its alloys makes it possible to solve the problem of static endurance of the apparatus, fatigue strength and, to some extent, creep.
• Another application of pure titanium is the manufacture of parts for electrovacuum devices designed for operation under overload conditions.
• The metal is indispensable in the production of cryogenic technology: the strength of titanium only increases with decreasing temperature, but some plasticity is retained.
• Titanium is perhaps the most biologically inert substance. Commercially pure metal is used to make all kinds of external and internal prostheses up to heart valves. Titanium is compatible with biological tissue and has not caused a single case of allergy. In addition, the material is used for surgical instruments, wheelchair crutches, wheelchairs and so on.

However, for all its resistance to temperatures and durability, the metal is not used in the manufacture of bearings, bushings and other parts where friction is expected. Titanium has low antifriction properties and this issue cannot be solved with the help of additives.

Titanium is well polished, anodized - color anodizing, therefore it is often used in works of art and in architecture. An example is a monument to the first artificial earth satellite or a monument. Y. Gagarin.

About the marking on titanium products, instructions for its use and other important points about the use of metal in construction, we will describe below.

The video below shows the titanium andonizing process:

Its use in construction

Of course, the lion's share of titanium is used in the aircraft industry and in the transport industry, where the combination of strength and lightness is especially important. However, the material is also used in construction, and would be used more widely if not for the high cost.

Titanium cladding

This technology is still not widespread, but, for example, in Japan, titanium sheets are very widely used for finishing roofs and even interiors. The share of material used in construction is much higher than that used in the aviation sector.

This is due both to the strength of such a cladding, and to its amazing decorative possibilities. By anodic oxidation, a layer of oxides of various thicknesses can be obtained on the sheet surface. The color then changes. By changing the annealing time and intensity, you can get yellow, turquoise, blue, pink, green colors.

When anodizing in a nitrogen atmosphere, sheets are made with a layer of titanium nitride. Thus, a wide variety of shades of gold are obtained. This technology is used in the restoration of architectural monuments - the restoration of churches, for example.

Seam roofs

This option is already very widespread. But, true, it is not titanium itself that serves as its basis, but its alloy with.

Seam roofs themselves have been known for a very long time, but have not been popular for a long time. However, today, thanks to the fashion for hi-tech and hi-tech styles, there is a need for broken and spline surfaces, especially those that go into the facade of the building. And it provides such an opportunity.

Her ability to form is almost limitless. And the use of the alloy provides both exceptional strength and the most unusual appearance. Although in fairness, the base matte steel color is considered the most respectable.

Since zinc-titanium has quite decent malleability, a variety of complex decorative details are made from the alloy: roof ridges, waterproof ebbs, cornices, and so on.

Such an area of ​​application of titanium as facade cladding is briefly discussed below.

Facade cladding

In the manufacture of facing panels, zinc-titanium is also used. Panels are used both for facade cladding and for interior decoration. The reason is the same - a combination of strength, exceptional lightness and decorativeness.

Panels of various shapes are produced - in the form of lamellas, rhombuses, modules, scales, and so on. The most interesting thing is that the panels may not be flat, but take on almost any three-dimensional shape. As a result, such a finish is possible on walls and buildings of any, the most unthinkable configuration.

The lightness of the product leads to another completely unique application. A conventional ventilated facade also implies a gap between the cladding and insulation. However, lightweight zinc-titanium panels can be mounted on movable opening mechanisms, forming a system similar to blinds. The plates, if necessary, can deviate from the plane by an angle of 90 degrees.

Titanium has a unique combination of strength, lightness and corrosion resistance. These qualities determine its use, despite the high cost of the material.

This video will tell you how to make a titanium ring:

The monument in honor of the conquerors of space was erected in Moscow in 1964. It took almost seven years (1958-1964) to design and build this obelisk. The authors had to solve not only architectural and artistic, but also technical problems. The first of them was the choice of materials, including facing. After long experiments, they settled on titanium sheets polished to a shine.

Indeed, in many characteristics, and above all in corrosion resistance, titanium surpasses the vast majority of metals and alloys. Sometimes (especially in popular literature) titanium is called the eternal metal. But first, let's talk about the history of this element.

Oxidized or not oxidized?

Until 1795, element No. 22 was called "menakin". So called it in 1791 by the English chemist and mineralogist William Gregor, who discovered a new element in the mineral menakanite (do not look for this name in modern mineralogical reference books - menakanite has also been renamed, now it is called ilmenite).

Four years after Gregor's discovery, the German chemist Martin Klaproth discovered a new chemical element in another mineral - rutile - and named it titanium in honor of the Elven queen Titania (Germanic mythology).

According to another version, the name of the element comes from the titans, the mighty sons of the goddess of the earth - Gaia (Greek mythology).

In 1797, it turned out that Gregor and Klaproth discovered the same element, and although Gregor had done this earlier, the name given to him by Klaproth was established for the new element.

But neither Gregor nor Klaproth succeeded in obtaining the elemental titanium. The white crystalline powder they isolated was titanium dioxide TiO 2 . For a long time none of the chemists succeeded in reducing this oxide, isolating pure metal from it.

In 1823, the English scientist W. Wollaston reported that the crystals he discovered in the metallurgical slags of the Merthyr Tydville plant were nothing but pure titanium. And 33 years later, the famous German chemist F. Wöhler proved that these crystals were again a titanium compound, this time a metal-like carbonitride.

For many years it was believed that metal Titanium was first obtained by Berzelius in 1825. in the reduction of potassium fluorotitanate with sodium metal. However, today, comparing the properties of titanium and the product obtained by Berzelius, it can be argued that the president of the Swedish Academy of Sciences was mistaken, because pure titabnum quickly dissolves in hydrofluoric acid (unlike many other acids), and Berzelius' metallic titanium successfully resisted its action.

In fact, Ti was first obtained only in 1875 by the Russian scientist D.K. Kirillov. The results of this work are published in his brochure Research on Titanium. But the work of a little-known Russian scientist went unnoticed. After another 12 years, a fairly pure product - about 95% titanium - was obtained by Berzelius's compatriots, the famous chemists L. Nilsson and O. Peterson, who reduced titanium tetrachloride with sodium metal in a steel hermetic bomb.

In 1895, the French chemist A. Moissan, reducing titanium dioxide with carbon in an arc furnace and subjecting the resulting material to double refining, obtained titanium containing only 2% impurities, mainly carbon. Finally, in 1910, the American chemist M. Hunter, having improved the method of Nilsson and Peterson, managed to obtain several grams of titanium with a purity of about 99%. That is why in most books the priority of obtaining metallic titanium is attributed to Hunter, and not to Kirillov, Nilson or Moissan.

However, neither Hunter nor his contemporaries predicted a great future for the titan. Only a few tenths of a percent of impurities were contained in the metal, but these impurities made titanium brittle, fragile, unsuitable for machining. Therefore, some titanium compounds found application earlier than the metal itself. Ti tetrachloride, for example, was widely used in the first world war to create smoke screens.

No. 22 in medicine

In 1908, in the USA and Norway, the production of white began not from lead and zinc compounds, as was done before, but from titanium dioxide. Such whitewash can paint a surface several times larger than the same amount of lead or zinc whitewash. In addition, titanium white has more reflectivity, they are not poisonous and do not darken under the influence of hydrogen sulfide. In the medical literature, a case is described when a person “took” 460 g of titanium dioxide at a time! (I wonder what he confused her with?) The "lover" of titanium dioxide did not experience any painful sensations. TiO 2 is part of some medicines, in particular ointments against skin diseases.

However, not medicine, but the paint and varnish industry consumes the largest amounts of TiO 2 . World production of this compound has far exceeded half a million tons per year. Enamels based on titanium dioxide are widely used as protective and decorative coatings for metal and wood in shipbuilding, construction and mechanical engineering. At the same time, the service life of structures and parts is significantly increased. Titanium white is used to dye fabrics, leather and other materials.

Ti in industry

Titanium dioxide is a constituent of porcelain masses, refractory glasses, and ceramic materials with a high dielectric constant. As a filler that increases strength and heat resistance, it is introduced into rubber compounds. However, all the advantages of titanium compounds seem insignificant against the background of the unique properties of pure metallic titanium.

elemental titanium

In 1925, the Dutch scientists van Arkel and de Boer obtained high purity titanium - 99.9% using the iodide method (more on that below). Unlike the titanium obtained by Hunter, it had plasticity: it could be forged in the cold, rolled into sheets, tape, wire, and even the thinnest foil. But even this is not the main thing. Studies of the physicochemical properties of metallic titanium led to almost fantastic results. It turned out, for example, that titanium, being almost twice as light as iron (the density of titanium is 4.5 g/cm3), surpasses many steels in strength. Comparison with aluminum also turned out to be in favor of titanium: titanium is only one and a half times heavier than aluminum, but it is six times stronger and, most importantly, it retains its strength at temperatures up to 500 ° C (and with the addition of alloying elements - up to 650 ° C ), while the strength of aluminum and magnesium alloys drops sharply already at 300°C.

Titanium also has significant hardness: it is 12 times harder than aluminum, 4 times harder than iron and copper. Another important characteristic of a metal is its yield strength. The higher it is, the better the details of this metal resist operational loads, the longer they retain their shape and size. The yield strength of titanium is almost 18 times higher than that of aluminum.

Unlike most metals, titanium has significant electrical resistance: if the electrical conductivity of silver is taken as 100, then the electrical conductivity of copper is 94, aluminum is 60, iron and platinum is 15, and titanium is only 3.8. It is hardly necessary to explain that this property, like the non-magnetic nature of titanium, is of interest for radio electronics and electrical engineering.

Remarkable resistance of titanium against corrosion. On a plate made of this metal for 10 years of being in sea water, there were no signs of corrosion. The main rotors of modern heavy helicopters are made of titanium alloys. Rudders, ailerons and some other critical parts of supersonic aircraft are also made of these alloys. In many chemical industries today you can find entire apparatuses and columns made of titanium.

How is titanium obtained?

Price - that's what else slows down the production and consumption of titanium. Actually, the high cost is not a congenital defect of titanium. There is a lot of it in the earth's crust - 0.63%. The still high price of titanium is a consequence of the difficulty of extracting it from ores. It is explained by the high affinity of titanium for many elements and the strength of chemical bonds in its natural compounds. Hence the complexity of the technology. This is how the magnesium-thermal method of titanium production looks like, developed in 1940 by the American scientist V. Kroll.

Titanium dioxide is converted with chlorine (in the presence of carbon) into titanium tetrachloride:

HO 2 + C + 2CI 2 → HCI 4 + CO 2.

The process takes place in shaft electric furnaces at 800-1250°C. Another option is chlorination in the melt of alkali metal salts NaCl and KCl. The next operation (which is equally important and time-consuming) is the purification of TiCl 4 from impurities - is carried out in different ways and substances. Titanium tetrachloride under normal conditions is a liquid with a boiling point of 136°C.

It is easier to break the bond of titanium with chlorine than with oxygen. This can be done with magnesium by the reaction

TiCl 4 + 2Mg → T + 2MgCl 2 .

This reaction takes place in steel reactors at 900°C. The result is a so-called titanium sponge impregnated with magnesium and magnesium chloride. They are evaporated in a sealed vacuum apparatus at 950°C, and the titanium sponge is then sintered or melted into a compact metal.

The sodium-thermal method for obtaining metallic titanium is, in principle, not much different from the magnesium-thermal method. These two methods are the most widely used in industry. To obtain purer titanium, the iodide method proposed by van Arkel and de Boer is still used. The metallothermic titanium sponge is converted to TiI 4 iodide, which is then sublimated in vacuo. On their way, titap iodide vapor encounters titanium wire heated to 1400°C. In this case, the iodide decomposes, and a layer of pure titanium grows on the wire. This method of titanium production is inefficient and expensive; therefore, it is used in industry to a very limited extent.

Despite the labor and energy intensity of titanium production, it has already become one of the most important non-ferrous metallurgy sub-sectors. World titanium production is developing at a very fast pace. This can be judged even by the fragmentary information that gets into print.

It is known that in 1948 only 2 tons of titanium were smelted in the world, and after 9 years - already 20 thousand tons. This means that in 1957 20 thousand tons of titanium accounted for all countries, and in 1980 only the USA consumed. 24.4 thousand tons of titanium... More recently, it seems, titanium was called a rare metal - now it is the most important structural material. This is explained by only one thing: a rare combination of the useful properties of element No. 22. And, of course, the needs of technology.

The role of titanium as a structural material, the basis of high-strength alloys for aviation, shipbuilding and rocketry, is rapidly increasing. It is in alloys that most of the titanium smelted in the world goes. A widely known alloy for the aviation industry, consisting of 90% titanium, 6% aluminum and 4% vanadium. In 1976, the American press reported on a new alloy for the same purpose: 85% titanium, 10% vanadium, 3% aluminum and 2% iron. It is claimed that this alloy is not only better, but also more economical.

In general, titanium alloys include a lot of elements, up to platinum and palladium. The latter (in the amount of 0.1-0.2%) increase the already high chemical resistance of titanium alloys.

The strength of titanium is also increased by such "alloying additives" as nitrogen and oxygen. But along with strength, they increase the hardness and, most importantly, the brittleness of titanium, so their content is strictly regulated: no more than 0.15% oxygen and 0.05% nitrogen are allowed in the alloy.

Despite the fact that titanium is expensive, replacing it with cheaper materials in many cases turns out to be economically viable. Here is a typical example. The case of a chemical apparatus made of stainless steel costs 150 rubles, and of a titanium alloy - 600 rubles. But at the same time, a steel reactor serves only 6 months, and a titanium one - 10 years. Add the cost of replacing steel reactors, the forced downtime of equipment - and it becomes obvious that using expensive titanium can be more profitable than steel.

Significant amounts of titanium are used in metallurgy. There are hundreds of grades of steels and other alloys that contain titanium as an alloying addition. It is introduced to improve the structure of metals, increase strength and corrosion resistance.

Some nuclear reactions must take place in an almost absolute void. With mercury pumps, the rarefaction can be brought up to several billionths of an atmosphere. But this is not enough, and mercury pumps are incapable of more. Further pumping of air is carried out by special titanium pumps. In addition, to achieve even greater rarefaction, fine titanium is sprayed onto the inner surface of the chamber where the reactions take place.

Titanium is often called the metal of the future. The facts that science and technology already have at their disposal convince us that this is not entirely true - titanium has already become the metal of the present.

Perovskite and sphene. Ilmenite - iron metatitanate FeTiO 3 - contains 52.65% TiO 2. The name of this mineral is due to the fact that it was found in the Urals in the Ilmensky mountains. The largest placers of ilmenite sands are found in India. Another important mineral, rutile, is titanium dioxide. Titanomagnetites are also of industrial importance - a natural mixture of ilmenite with iron minerals. There are rich deposits of titanium ores in the USSR, USA, India, Norway, Canada, Australia and other countries. Not so long ago, geologists discovered a new titanium-containing mineral in the Northern Baikal region, which was named landauite in honor of the Soviet physicist Academician L. D. Landau. In total, more than 150 significant ore and placer titanium deposits are known on the globe.

In the periodic system, the chemical element titanium is designated as Ti (Titanium) and is located in a side subgroup of group IV, in period 4 under atomic number 22. It is a silvery-white solid metal that is part of a large number of minerals. You can buy titanium on our website.

Titanium was discovered at the end of the 18th century by chemists from England and Germany, William Gregor and Martin Klaproth, independently of each other with a six-year difference. It was Martin Klaproth who gave the name to the element in honor of the ancient Greek characters of the titans (huge, strong, immortal creatures). As it turned out, the name became prophetic, but it took humanity even more than 150 years to get acquainted with all the properties of titanium. Only three decades later, the first sample of titanium metal was obtained. At that time, it was practically not used due to its fragility. In 1925, after a series of experiments, chemists Van Arkel and De Boer obtained pure titanium using the iodide method.

Due to the valuable properties of the metal, engineers and designers immediately drew attention to it. It was a real breakthrough. In 1940, Kroll developed a magnesium-thermal method for obtaining titanium from ore. This method is still relevant today.

Physical and mechanical properties

Titanium is a fairly refractory metal. Its melting point is 1668±3°C. According to this indicator, it is inferior to such metals as tantalum, tungsten, rhenium, niobium, molybdenum, tantalum, zirconium. Titanium is a paramagnetic metal. In a magnetic field, it is not magnetized, but it is not pushed out of it. Picture 2
Titanium has a low density (4.5 g/cm³) and high strength (up to 140 kg/mm²). These properties practically do not change at high temperatures. It is more than 1.5 times heavier than aluminum (2.7 g/cm³), but 1.5 times lighter than iron (7.8 g/cm³). In terms of mechanical properties, titanium is far superior to these metals. In terms of strength, titanium and its alloys are on a par with many grades of alloyed steels.

In terms of corrosion resistance, titanium is not inferior to platinum. The metal has excellent resistance to cavitation conditions. Air bubbles formed in a liquid medium during the active movement of a titanium part practically do not destroy it.

It is a durable metal that can resist fracture and plastic deformation. It is 12 times harder than aluminum and 4 times harder than copper and iron. Another important indicator is the yield strength. With an increase in this indicator, the resistance of titanium parts to operational loads improves.

In alloys with certain metals (especially nickel and hydrogen), titanium is able to "remember" the shape of the product created at a certain temperature. Such a product can then be deformed and it will retain this position for a long time. If the product is heated to the temperature at which it was made, then the product will take its original shape. This property is called "memory".

The thermal conductivity of titanium is relatively low and the coefficient of linear expansion, respectively, too. From this it follows that the metal is a poor conductor of electricity and heat. But at low temperatures, it is a superconductor of electricity, which allows it to transmit energy over considerable distances. Titanium also has a high electrical resistance.
Pure titanium metal is subject to various types of cold and hot processing. It can be drawn and made into wire, forged, rolled into strips, sheets and foils with a thickness of up to 0.01 mm. The following types of rolled products are made from titanium: titanium tape, titanium wire, titanium pipes, titanium bushings, titanium circle, titanium bar.

Chemical properties

Pure titanium is a reactive element. Due to the fact that a dense protective film is formed on its surface, the metal is highly resistant to corrosion. It does not undergo oxidation in air, in salty sea water, does not change in many aggressive chemical environments (for example: dilute and concentrated nitric acid, aqua regia). At high temperatures, titanium interacts with reagents much more actively. It ignites in air at a temperature of 1200°C. When ignited, the metal gives off a bright glow. An active reaction also occurs with nitrogen, with the formation of a yellow-brown nitride film on the surface of titanium.

Reactions with hydrochloric and sulfuric acids at room temperature are weak, but when heated, the metal is strongly dissolved. As a result of the reaction, lower chlorides and monosulfate are formed. Weak interactions with phosphoric and nitric acids also occur. The metal reacts with halogens. The reaction with chlorine occurs at 300°C.
The active reaction with hydrogen proceeds at a temperature slightly above room temperature. Titanium actively absorbs hydrogen. 1 g of titanium can absorb up to 400 cm³ of hydrogen. The heated metal decomposes carbon dioxide and water vapor. Interaction with water vapor occurs at temperatures above 800°C. As a result of the reaction, metal oxide is formed and hydrogen escapes. At higher temperatures, hot titanium absorbs carbon dioxide and forms carbide and oxide.

How to get

Titanium is one of the most common elements on Earth. Its content in the bowels of the planet by weight is 0.57%. The highest concentration of the metal is observed in the "basalt shell" (0.9%), in granitic rocks (0.23%) and in ultrabasic rocks (0.03%). There are about 70 titanium minerals that contain it in the form of titanic acid or dioxide. The main minerals of titanium ores are: ilmenite, anatase, rutile, brookite, loparite, leucoxene, perovskite and sphene. The main world producers of titanium are Great Britain, the USA, France, Japan, Canada, Italy, Spain and Belgium.
There are several ways to obtain titanium. All of them are applied in practice and are quite effective.

1. Magnesium thermal process.

Ore containing titanium is mined and processed into dioxide, which is slowly and at very high temperatures subjected to chlorination. Chlorination is carried out in a carbon environment. The titanium chloride formed as a result of the reaction is then reduced with magnesium. The resulting metal is heated in a vacuum equipment at a high temperature. As a result, magnesium and magnesium chloride evaporate, leaving titanium with many pores and voids. Sponge titanium is remelted to produce high-quality metal.

2. Hydride-calcium method.

First, titanium hydride is obtained, and then it is separated into components: titanium and hydrogen. The process takes place in an airless space at high temperature. Calcium oxide is formed, which is washed with weak acids.
Calcium hydride and magnesium thermal methods are commonly used on an industrial scale. These methods make it possible to obtain a significant amount of titanium in a short period of time, with minimal monetary costs.

3. Electrolysis method.

Titanium chloride or dioxide is exposed to a high current. As a result, the compounds are decomposed.

4. Iodide method.

Titanium dioxide interacts with iodine vapor. Next, titanium iodide is exposed to high temperature, resulting in titanium. This method is the most efficient, but also the most expensive. Titanium is of very high purity without impurities and additives.

Application of titanium

Due to its good anti-corrosion properties, titanium is used for the manufacture of chemical equipment. The high heat resistance of the metal and its alloys contributes to the use in modern technology. Titanium alloys are an excellent material for aircraft, rocket and shipbuilding.

Monuments are made from titanium. And the bells made of this metal are known for their extraordinary and very beautiful sound. Titanium dioxide is a component of some medicines, for example: ointments against skin diseases. Metal compounds with nickel, aluminum and carbon are also in great demand.

Titanium and its alloys have found application in such areas as the chemical and food industries, non-ferrous metallurgy, electronics, nuclear technology, power engineering, electroplating. Weapons, armor plates, surgical instruments and implants, irrigation systems, sports equipment and even jewelry are made from titanium and its alloys. In the process of nitriding, a golden film is formed on the surface of the metal, which is not inferior in beauty even to real gold.