What is the highest oxidation state of titanium. Titanium, zirconium and hafnium compounds

The discovery of TiO 2 was made almost simultaneously and independently by the Englishman W. Gregor and the German chemist M. G. Klaproth. W. Gregor, studying the composition of magnetic ferruginous sand (Creed, Cornwall, England, 1789), isolated a new "earth" (oxide) of an unknown metal, which he called menaken. In 1795, the German chemist Klaproth discovered a new element in the mineral rutile and called it titanium, and later established that rutile and menaken earth are oxides of the same element. The first sample of metallic titanium was obtained in 1825 by J. Ya. Berzelius. A pure Ti sample was obtained by the Dutch A. van Arkel and J. de Boer in 1925 by thermal decomposition of titanium iodide TiI 4 vapors.

Physical properties:

Titanium is a light, silvery-white metal. Plastic, welded in an inert atmosphere.
It has a high viscosity, during machining it is prone to sticking to the cutting tool, and therefore the application of special coatings on the tool, various lubricants is required.

Chemical properties:

At normal temperature, it is covered with a protective passivating oxide film, corrosion-resistant, but when crushed into powder, it burns in air. Titanium dust can explode (flash point 400°C). When heated in air to 1200°C, titanium burns out with the formation of oxide phases of variable composition TiO x .
Titanium is resistant to dilute solutions of many acids and alkalis (except HF, H 3 PO 4 and concentrated H 2 SO 4), however, it easily reacts even with weak acids in the presence of complexing agents, for example, with hydrofluoric acid HF forms a complex anion 2-.
When heated, titanium interacts with halogens. With nitrogen above 400°C, titanium forms the nitride TiN x (x=0.58-1.00). When titanium interacts with carbon, titanium carbide TiC x (x=0.49-1.00) is formed.
Titanium absorbs hydrogen, forming compounds of variable composition TiH x . When heated, these hydrides decompose with the release of H 2 .
Titanium forms alloys with many metals.
In compounds, titanium exhibits oxidation states +2, +3 and +4. The most stable oxidation state is +4.

The most important connections:

Titanium dioxide, TiO 2 . White powder, yellow when heated, density 3.9-4.25 g/cm 3 . Amphoterene. In concentrated H 2 SO 4 it dissolves only with prolonged heating. When fused with soda Na 2 CO 3 or potash K 2 CO 3, TiO 2 oxide forms titanates:
TiO 2 + K 2 CO 3 \u003d K 2 TiO 3 + CO 2
Titanium(IV) hydroxide, TiO(OH) 2 *xH 2 O, is precipitated from solutions of titanium salts, it is carefully calcined to obtain TiO 2 oxide. Titanium(IV) hydroxide is amphoteric.
Titanium tetrachloride, TiCl 4 , under normal conditions - a yellowish, highly fuming liquid in air, which is explained by the strong hydrolysis of TiCl 4 with water vapor and the formation of tiny droplets of HCl and a suspension of titanium hydroxide. Boiling water hydrolyzes to titanic acid(??). Titanium(IV) chloride is characterized by the formation of addition products, for example, TiCl 4 *6NH 3, TiCl 4 *8NH 3, TiCl 4 *PCl 3, etc. When titanium(IV) chloride is dissolved in HCl, complex acid H 2 is formed, which is unknown in the free state; its Me 2 salts crystallize well and are stable in air.
Reduction of TiCl 4 with hydrogen, aluminum, silicon, and other strong reducing agents, titanium trichloride and dichloride TiCl 3 and TiCl 2 are obtained - solid substances with strong reducing properties.
Titanium nitride- is an interstitial phase with a wide area of ​​homogeneity, crystals with a cubic face-centered lattice. Obtaining - by nitriding titanium at 1200 ° C or by other methods. It is used as a heat-resistant material to create wear-resistant coatings.

Application:

in the form of alloys. The metal is used in the chemical industry (reactors, pipelines, pumps), light alloys, osteoprostheses. It is the most important structural material in aircraft, rocket and shipbuilding.
Titanium is an alloying addition in some steel grades.
Nitinol (nickel-titanium) is a shape memory alloy used in medicine and technology.
Titanium aluminides are very resistant to oxidation and heat-resistant, which in turn determined their use in aviation and automotive industry as structural materials.
In the form of connections White titanium dioxide is used in paints (for example, titanium white), as well as in the production of paper and plastics. Food additive E171.
Organotitanium compounds (eg tetrabutoxytitanium) are used as a catalyst and hardener in the chemical and paint industries.
Inorganic titanium compounds are used in the chemical, electronic, fiberglass industry as an additive.

Matigorov A.V.
HF Tyumen State University

Zirconium and hafnium form compounds in the +4 oxidation state, titanium is also capable of forming compounds in the +3 oxidation state.

Compounds with an oxidation state of +3. Titanium(III) compounds are obtained by reduction of titanium(IV) compounds. For example:

1200 ºС 650 ºС

2TiO 2 + H 2 ¾® Ti 2 O 3 + H 2 O; 2TiCl 4 + H 2 ¾® 2TiCl 3 + 2HCl

Titanium(III) compounds are purple. Titanium oxide practically does not dissolve in water, it exhibits basic properties. Oxide, chloride, Ti 3+ salts are strong reducing agents:

4Ti +3 Cl 3 + O 2 + 2H 2 O \u003d 4Ti +4 OCl 2 + 4HCl

For titanium(III) compounds, disproportionation reactions are possible:

2Ti +3 Cl 3 (t) ¾® Ti +4 Cl 4 (g) + Ti +2 Cl 2 (t)

On further heating, titanium(II) chloride also disproportionates:

2Ti +2 Cl 2 (t) \u003d Ti 0 (t) + Ti +4 Cl 4 (g)

Compounds with an oxidation state of +4. Titanium (IV), zirconium (IV) and hafnium (IV) oxides are refractory, chemically rather inert substances. They exhibit the properties of amphoteric oxides: they slowly react with acids during prolonged boiling and interact with alkalis during fusion:

TiO 2 + 2H 2 SO 4 \u003d Ti (SO 4) 2 + 2H 2 O;

TiO 2 + 2NaOH \u003d Na 2 TiO 3 + H 2 O

Titanium oxide TiO 2 finds the widest application; it is used as a filler in the production of paints, rubber, and plastics. Zirconium oxide ZrO 2 is used for the manufacture of refractory crucibles and plates.

Hydroxides titanium (IV), zirconium (IV) and hafnium (IV) - amorphous compounds of variable composition - EO 2 × nH 2 O. Freshly obtained substances are quite reactive and dissolve in acids, titanium hydroxide is also soluble in alkalis. Aged sediments are extremely inert.

Halides(chlorides, bromides and iodides) Ti(IV), Zr(IV) and Hf(IV) have a molecular structure, are volatile and reactive, and are easily hydrolyzed. When heated, iodides decompose to form metals, which is used in the production of high purity metals. For example:

TiI 4 = Ti + 2I 2

Titanium, zirconium and hafnium fluorides are polymeric and poorly reactive.

salt elements of the titanium subgroup in the +4 oxidation state are few and hydrolytically unstable. Usually, when oxides or hydroxides react with acids, not medium salts are formed, but oxo- or hydroxo derivatives. For example:

TiO 2 + 2H 2 SO 4 \u003d TiOSO 4 + H 2 O; Ti (OH) 4 + 2HCl \u003d TiOСl 2 + H 2 O

A large number of anionic complexes of titanium, zirconium, and hafnium have been described. The most stable in solutions and easily formed fluoride compounds:

EO 2 + 6HF \u003d H 2 [EF 6] + 2H 2 O; EF 4 + 2KF \u003d K 2 [EF 6]

Titanium and its analogs are characterized by coordination compounds in which the peroxide anion plays the role of a ligand:

E (SO 4) 2 + H 2 O 2 \u003d H 2 [E (O 2) (SO 4) 2]

In this case, solutions of titanium(IV) compounds acquire a yellow-orange color, which makes it possible to analytically detect titanium(IV) cations and hydrogen peroxide.

Hydrides (EN 2), carbides (ES), nitrides (EN), silicides (ESi 2) and borides (EV, EV 2) are compounds of variable composition, metal-like. Binary compounds have valuable properties that allow them to be used in technology. For example, an alloy of 20% HfC and 80% TiC is one of the most refractory, m.p. 4400 ºС.

DEFINITION

Titanium located in the fourth period of group IV of the secondary (B) subgroup of the Periodic Table. Designation - Ti. In the form of a simple substance, titanium is a silvery-white metal.

Refers to light metals. Refractory. Density - 4.50 g/cm 3 . The melting and boiling points are 1668 o C and 3330 o C, respectively.

Titanium is corrosion-resistant when exposed to air at normal temperature, which is explained by the presence of a protective film of TiO 2 composition on its surface. Chemically stable in many aggressive environments (solutions of sulfates, chlorides, sea water, etc.).

The oxidation state of titanium in compounds

Titanium can exist in the form of a simple substance - a metal, and the oxidation state of metals in the elemental state is zero, since the distribution of electron density in them is uniform.

In its compounds, titanium is able to exhibit oxidation states (+2) (Ti +2 H 2, Ti +2 O, Ti +2 (OH) 2, Ti +2 F 2, Ti +2 Cl 2, Ti +2 Br 2), (+3) (Ti +3 2 O 3 , Ti +3 (OH) 3 , Ti +3 F 3 , Ti +3 Cl 3 , Ti +3 2 S 3) and (+4) (Ti +4 F 4 , Ti +4 H 4 , Ti +4 Cl 4 , Ti +4 Br 4).

Examples of problem solving

EXAMPLE 1

Exercise	Valence III and oxidation state (-3) nitrogen shows in the compound: a) N 2 H 4; b) NH3; c) NH 4 Cl; d) N 2 O 5
Decision	In order to give a correct answer to the question posed, we will alternately determine the valency and oxidation state of nitrogen in the proposed compounds. a) the valency of hydrogen is always equal to I. The total number of hydrogen valency units is 4 (1 × 4 = 4). Divide the value obtained by the number of nitrogen atoms in the molecule: 4/2 \u003d 2, therefore, the nitrogen valency is II. This answer is incorrect. b) the valency of hydrogen is always equal to I. The total number of hydrogen valence units is 3 (1 × 3 = 3). We divide the obtained value by the number of nitrogen atoms in the molecule: 3/1 \u003d 2, therefore, the nitrogen valency is III. The oxidation state of nitrogen in ammonia is (-3): This is the correct answer.
Answer	Option (b).

EXAMPLE 2

Exercise	Chlorine has the same oxidation state in each of the two compounds: a) FeCl 3 and Cl 2 O 5; b) KClO 3 and Cl 2 O 5; c) NaCl and HClO; d) KClO 2 and CaCl 2.
Decision	In order to give a correct answer to the question posed, we will alternately determine the degree of oxidation of chlorine in each pair of the proposed compounds. a) The oxidation state of iron is (+3), and oxygen - (-2). Let's take the value of the oxidation state of chlorine as "x" and "y" in iron (III) chloride and chlorine oxide, respectively: y×2 + (-2)×5 = 0; The answer is incorrect. b) The oxidation states of potassium and oxygen are (+1) and (-2), respectively. Let's take the value of the oxidation state of chlorine as "x" and "y" in the proposed compounds: 1 + x + (-2)×3 = 0; y×2 + (-2)×5 = 0; The answer is correct.
Answer	Option (b).

Eternal, mysterious, cosmic - all these and many other epithets are assigned to titanium in various sources. The history of the discovery of this metal was not trivial: at the same time, several scientists worked on isolating the element in its pure form. The process of studying the physical, chemical properties and determining the areas of its application today. Titanium is the metal of the future, its place in human life has not yet been finally determined, which gives modern researchers a huge scope for creativity and scientific research.

Characteristic

The chemical element is indicated in the periodic table of D. I. Mendeleev by the symbol Ti. It is located in the secondary subgroup of group IV of the fourth period and has serial number 22. titanium is a white-silver metal, light and durable. The electronic configuration of an atom has the following structure: +22)2)8)10)2, 1S 2 2S 2 2P 6 3S 2 3P 6 3d 2 4S 2. Accordingly, titanium has several possible oxidation states: 2, 3, 4; in the most stable compounds, it is tetravalent.

Titanium - alloy or metal?

This question interests many. In 1910, the American chemist Hunter obtained the first pure titanium. The metal contained only 1% of impurities, but at the same time, its amount turned out to be negligible and did not make it possible to further study its properties. The plasticity of the obtained substance was achieved only under the influence of high temperatures; under normal conditions (room temperature), the sample was too fragile. In fact, this element did not interest scientists, since the prospects for its use seemed too uncertain. The difficulty of obtaining and research further reduced the potential for its application. Only in 1925, chemists from the Netherlands I. de Boer and A. Van Arkel received titanium metal, the properties of which attracted the attention of engineers and designers around the world. The history of the study of this element begins in 1790, exactly at this time, in parallel, independently of each other, two scientists discover titanium as a chemical element. Each of them receives a compound (oxide) of a substance, failing to isolate the metal in its pure form. The discoverer of titanium is the English mineralogist monk William Gregor. On the territory of his parish, located in the southwestern part of England, the young scientist began to study the black sand of the Menaken valley. The result was the release of shiny grains, which were a titanium compound. At the same time, in Germany, the chemist Martin Heinrich Klaproth isolated a new substance from the mineral rutile. In 1797, he also proved that elements opened in parallel are similar. Titanium dioxide has been a mystery to many chemists for more than a century, and even Berzelius was unable to obtain pure metal. The latest technologies of the 20th century significantly accelerated the process of studying the mentioned element and determined the initial directions for its use. At the same time, the scope of application is constantly expanding. Only the complexity of the process of obtaining such a substance as pure titanium can limit its scope. The price of alloys and metal is quite high, so today it cannot displace traditional iron and aluminum.

origin of name

Menakin is the first name for titanium, which was used until 1795. That is how, by territorial affiliation, W. Gregor called the new element. Martin Klaproth gives the element the name "titanium" in 1797. At this time, his French colleagues, led by a fairly reputable chemist A. L. Lavoisier, proposed to name the newly discovered substances in accordance with their basic properties. The German scientist did not agree with this approach, he quite reasonably believed that at the discovery stage it is quite difficult to determine all the characteristics inherent in a substance and reflect them in the name. However, it should be recognized that the term intuitively chosen by Klaproth fully corresponds to the metal - this has been repeatedly emphasized by modern scientists. There are two main theories for the origin of the name titanium. The metal could have been designated in honor of the Elven queen Titania (a character in Germanic mythology). This name symbolizes both the lightness and strength of the substance. Most scientists are inclined to use the version of the use of ancient Greek mythology, in which the powerful sons of the goddess of the earth Gaia were called titans. The name of the previously discovered element, uranium, also speaks in favor of this version.

Being in nature

Of the metals that are technically valuable to humans, titanium is the fourth most abundant in the earth's crust. Only iron, magnesium and aluminum are characterized by a large percentage in nature. The highest content of titanium is noted in the basalt shell, slightly less in the granite layer. In sea water, the content of this substance is low - approximately 0.001 mg / l. The chemical element titanium is quite active, so it cannot be found in its pure form. Most often, it is present in compounds with oxygen, while it has a valency of four. The number of titanium-containing minerals varies from 63 to 75 (in various sources), while at the present stage of research, scientists continue to discover new forms of its compounds. For practical use, the following minerals are of greatest importance:

1. Ilmenite (FeTiO 3).
2. Rutile (TiO 2).
3. Titanite (CaTiSiO 5).
4. Perovskite (CaTiO 3).
5. Titanomagnetite (FeTiO 3 + Fe 3 O 4), etc.

All existing titanium-containing ores are divided into placer and basic. This element is a weak migrant, it can travel only in the form of rock fragments or moving silty bottom rocks. In the biosphere, the largest amount of titanium is found in algae. In representatives of the terrestrial fauna, the element accumulates in the horny tissues, hair. The human body is characterized by the presence of titanium in the spleen, adrenal glands, placenta, thyroid gland.

Physical properties

Titanium is a non-ferrous metal with a silvery-white color that looks like steel. At a temperature of 0 0 C, its density is 4.517 g / cm 3. The substance has a low specific gravity, which is typical for alkali metals (cadmium, sodium, lithium, cesium). In terms of density, titanium occupies an intermediate position between iron and aluminum, while its performance is higher than that of both elements. The main properties of metals, which are taken into account when determining the scope of their application, are hardness. Titanium is 12 times stronger than aluminum, 4 times stronger than iron and copper, while being much lighter. Plasticity and its yield strength allow processing at low and high temperatures, as in the case of other metals, i.e., riveting, forging, welding, rolling. A distinctive characteristic of titanium is its low thermal and electrical conductivity, while these properties are preserved at elevated temperatures, up to 500 0 C. In a magnetic field, titanium is a paramagnetic element, it is not attracted like iron, and is not pushed out like copper. Very high anti-corrosion performance in aggressive environments and under mechanical stress is unique. More than 10 years of being in sea water did not change the appearance and composition of the titanium plate. Iron in this case would be completely destroyed by corrosion.

Thermodynamic properties of titanium

1. The density (under normal conditions) is 4.54 g/cm 3 .
2. The atomic number is 22.
3. Group of metals - refractory, light.
4. The atomic mass of titanium is 47.0.
5. Boiling point (0 C) - 3260.
6. Molar volume cm 3 / mol - 10.6.
7. The melting point of titanium (0 C) is 1668.
8. Specific heat of evaporation (kJ / mol) - 422.6.
9. Electrical resistance (at 20 0 C) Ohm * cm * 10 -6 - 45.

Chemical properties

The increased corrosion resistance of the element is explained by the formation of a small oxide film on the surface. It prevents (under normal conditions) from gases (oxygen, hydrogen) in the surrounding atmosphere of an element such as titanium metal. Its properties change under the influence of temperature. When it rises to 600 0 C, an interaction reaction with oxygen occurs, resulting in the formation of titanium oxide (TiO 2). In the case of absorption of atmospheric gases, brittle joints are formed that have no practical application, which is why welding and melting of titanium are carried out under vacuum conditions. The reversible reaction is the process of dissolution of hydrogen in the metal, it occurs more actively with an increase in temperature (from 400 0 C and above). Titanium, especially its small particles (thin plate or wire), burns in a nitrogen atmosphere. A chemical reaction of interaction is possible only at a temperature of 700 0 C, resulting in the formation of TiN nitride. Forms highly hard alloys with many metals, often as an alloying element. It reacts with halogens (chromium, bromine, iodine) only in the presence of a catalyst (high temperature) and subject to interaction with a dry substance. In this case, very hard refractory alloys are formed. With solutions of most alkalis and acids, titanium is not chemically active, with the exception of concentrated sulfuric (with prolonged boiling), hydrofluoric, hot organic (formic, oxalic).

Place of Birth

Ilmenite ores are the most common in nature - their reserves are estimated at 800 million tons. The deposits of rutile deposits are much more modest, but the total volume - while maintaining the growth of production - should provide mankind for the next 120 years with such a metal as titanium. The price of the finished product will depend on demand and an increase in the level of manufacturability, but on average it varies in the range from 1200 to 1800 rubles/kg. In conditions of constant technical improvement, the cost of all production processes is significantly reduced with their timely modernization. China and Russia have the largest reserves, Japan, South Africa, Australia, Kazakhstan, India, South Korea, Ukraine, Ceylon also have a mineral resource base. The deposits differ in the volume of production and the percentage of titanium in the ore, geological surveys are ongoing, which makes it possible to assume a decrease in the market value of the metal and its wider use. Russia is by far the largest producer of titanium.

Receipt

For the production of titanium, titanium dioxide, which contains a minimum amount of impurities, is most often used. It is obtained by enrichment of ilmenite concentrates or rutile ores. In the electric arc furnace, the heat treatment of the ore takes place, which is accompanied by the separation of iron and the formation of slag containing titanium oxide. The sulfate or chloride method is used to process the iron-free fraction. Titanium oxide is a gray powder (see photo). Titanium metal is obtained by its phased processing.

The first phase is the process of sintering the slag with coke and exposure to chlorine vapor. The resulting TiCl 4 is reduced with magnesium or sodium when exposed to a temperature of 850 0 C. The titanium sponge (porous fused mass) obtained as a result of a chemical reaction is purified or melted into ingots. Depending on the further direction of use, an alloy or pure metal is formed (impurities are removed by heating to 1000 0 C). For the production of a substance with an impurity content of 0.01%, the iodide method is used. It is based on the process of evaporation of its vapors from a titanium sponge pre-treated with halogen.

Applications

The melting temperature of titanium is quite high, which, given the lightness of the metal, is an invaluable advantage of using it as a structural material. Therefore, it finds the greatest application in shipbuilding, the aviation industry, the manufacture of rockets, and chemical industries. Titanium is quite often used as an alloying additive in various alloys, which have increased hardness and heat resistance characteristics. High anti-corrosion properties and the ability to withstand most aggressive environments make this metal indispensable for the chemical industry. Titanium (its alloys) is used to make pipelines, tanks, valves, filters used in the distillation and transportation of acids and other chemically active substances. It is in demand when creating devices operating in conditions of elevated temperature indicators. Titanium compounds are used to make durable cutting tools, paints, plastics and paper, surgical instruments, implants, jewelry, finishing materials, and are used in the food industry. All directions are difficult to describe. Modern medicine, due to complete biological safety, often uses titanium metal. Price is the only factor that so far affects the breadth of application of this element. It is fair to say that titanium is the material of the future, by studying which humanity will move to a new stage of development.

1941 Boiling temperature 3560 Oud. heat of fusion 18.8 kJ/mol Oud. heat of evaporation 422.6 kJ/mol Molar heat capacity 25.1 J/(K mol) Molar volume 10.6 cm³/mol Crystalline lattice of a simple substance Lattice structure hexagonal
close-packed (α-Ti) Lattice parameters a=2.951 c=4.697 (α-Ti) Attitude c/a 1,587 Temperature Debye 380 Other characteristics Thermal conductivity (300 K) 21.9 W/(m K) No CAS 7440-32-6

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Subtitles

Hello! Alexander Ivanov is with you and this is the project “Chemistry is simple” And now we will light it up a little with titanium! This is how a few grams of pure titanium look like, which were obtained a long time ago at the University of Manchester, when it was not even a university yet. This sample is from that same museum. This is how the main mineral from which titanium is extracted looks like. This is Rutile. contain titanium In 1867, everything that people knew about titanium fit in a textbook on 1 page By the beginning of the 20th century, nothing really changed In 1791, the English chemist and mineralogist William Gregor discovered a new element in the mineral menakinite and called it "menakin" A little later, in 1795, the German chemist Martin Klaproth discovered a new chemical element in another mineral - rutile. Titanium got its name from Klaproth, who named it in honor of the queen of the elves Titania. However, according to another version, the name of the element comes from the titans, the mighty sons of the goddess of the earth - Gays However, in 1797 it turned out that Gregor and Klaproth discovered the same chemical element. But the name the one that Klaproth gave remained. But, neither Gregor nor Klaproth were able to obtain metallic titanium. They obtained a white crystalline powder, which was titanium dioxide. For the first time, metallic titanium was obtained by the Russian scientist D.K. Kirilov in 1875 But as it happens without proper coverage, his work was not noticed. After that, pure titanium was obtained by the Swedes L. Nilsson and O. Peterson, as well as the Frenchman Moissan. And only in 1910, the American chemist M. Hunter improved the previous methods for producing titanium and received several grams of pure 99% titanium. That is why in most books it is Hunter who indicates how the scientist who received metallic titanium Nobody prophesied a great future for titanium, since the slightest impurities in its composition made it very fragile and fragile, which did not allow mechanical processing Therefore, some titanium compounds found their widespread use before the metal itself. Titanium tetrachloride was used in the first world war to create smoke screens. In the open air, titanium tetrachloride hydrolyzes to form titanium oxychlorides and titanium oxide. The white smoke that we see is the particles of oxychlorides. and titanium oxide What exactly are these particles We can confirm if we drop a few drops of titanium tetrachloride into water. Titanium tetrachloride is currently used to obtain metallic titanium. The method for obtaining pure titanium has not changed in a hundred years. First, titanium dioxide is converted with chlorine into titanium tetrachloride, which we talked about earlier. Then, with the help of magnesiumthermia, titanium metal is obtained from titanium tetrachloride, which is formed in the form of a sponge. This process is carried out at a temperature of 900 ° C in steel retorts Due to the harsh reaction conditions, we unfortunately do not have the opportunity to show this process. As a result, a titanium sponge is obtained, which is smelted into a compact metal. To obtain ultrapure titanium, an iodide refining method is used, which we will discuss in detail in the video about zirconium. As you have already noticed, titanium tetrachloride is a transparent, colorless liquid under normal conditions. But if we take titanium trichloride, it is a solid purple thing. sity Just one less chlorine atom in the molecule, and already a different state Titanium trichloride is hygroscopic. Therefore, you can work with it only in an inert atmosphere. Titanium trichloride dissolves well in hydrochloric acid. You are now observing this process. A complex ion 3 is formed in the solution. What are complex ions, I will tell you some other time next time. In the meantime, just be horrified :) If you add a little nitric acid to the resulting solution, then titanium nitrate is formed and brown gas is released, which we actually see. There is a qualitative reaction to titanium ions. We drop hydrogen peroxide. As you can see, a reaction occurs with the formation of a brightly colored compound This is pertitanic acid. In 1908, titanium dioxide was used in the United States for the production of white, which replaced white, which was based on lead and zinc. Titanium white was much superior in quality to lead and zinc counterparts. Also, titanium oxide was used to produce enamel, which was used for metal and wood coatings in shipbuilding Currently, titanium dioxide is used in the food industry as a white dye - this is an additive E171, which can be found in crab sticks, breakfast cereals, mayonnaise, chewing gum, dairy products, etc. Also, titanium dioxide is used in cosmetics - he enters the sos having sunscreen "All that glitters is not gold" - we know this saying from childhood And in relation to the modern church and titanium, it literally works And it seems, what can be in common between the church and titanium? And here's what: all modern domes of churches that shimmer with gold, in fact, have nothing to do with gold. In fact, all domes are coated with titanium nitride. Also, metal drills are coated with titanium nitride. Only in 1925, high-purity titanium was obtained, which made it possible to study it. physical and chemical properties And they turned out to be fantastic. It turned out that titanium, being almost twice as light as iron, surpasses many steels in strength. Also, although titanium is one and a half times heavier than aluminum, it is six times stronger than it and retains its strength up to 500 ° C. - due to its high electrical conductivity and non-magnetism, titanium is of high interest in electrical engineering Titanium has a high resistance to corrosion Due to its properties, titanium has become a material for space technology In Russia, in Verkhnyaya Salda, there is a corporation VSMPO-AVISMA, which produces titanium for the world aerospace industry From Verkhne Salda titanium make Boeings, Airbuses, Rolls-Ro ice cubes, various chemical equipment and many other expensive junk However, each of you can purchase a shovel or crowbar made of pure titanium! And it's not a joke! And this is how finely dispersed titanium powder reacts with atmospheric oxygen Thanks to such colorful combustion, titanium has found application in pyrotechnics And that's all, subscribe, put your finger up, don't forget to support the project and tell your friends! Till!

Story

The discovery of TiO 2 was made almost simultaneously and independently by an Englishman W. Gregor?! and the German chemist M. G. Klaproth. W. Gregor, studying the composition of magnetic ferruginous sand (Creed, Cornwall, England,), isolated a new "earth" (oxide) of an unknown metal, which he called menaken. In 1795, the German chemist Klaproth discovered a new element in the mineral rutile and named it titanium. Two years later, Klaproth established that rutile and menaken earth are oxides of the same element, behind which the name "titanium" proposed by Klaproth remained. After 10 years, the discovery of titanium took place for the third time. The French scientist L. Vauquelin discovered titanium in anatase and proved that rutile and anatase are identical titanium oxides.

The first sample of metallic titanium was obtained in 1825 by J. Ya. Berzelius. Due to the high chemical activity of titanium and the complexity of its purification, the Dutch A. van Arkel and I. de Boer obtained a pure sample of Ti in 1925 by thermal decomposition of titanium iodide vapor TiI 4 .

origin of name

The metal got its name in honor of the titans, the characters of ancient Greek mythology, the children of Gaia. The name of the element was given by Martin Klaproth in accordance with his views on chemical nomenclature, as opposed to the French school of chemistry, where they tried to name the element by its chemical properties. Since the German researcher himself noted the impossibility of determining the properties of a new element only by its oxide, he chose a name for it from mythology, by analogy with uranium discovered by him earlier.

Being in nature

Titanium is the 10th most abundant in nature. The content in the earth's crust is 0.57% by mass, in sea water - 0.001 mg / l. 300 g/t in ultrabasic rocks, 9 kg/t in basic rocks, 2.3 kg/t in acid rocks, 4.5 kg/t in clays and shales. In the earth's crust, titanium is almost always tetravalent and is present only in oxygen compounds. It does not occur in free form. Titanium under conditions of weathering and precipitation has a geochemical affinity for Al 2 O 3 . It is concentrated in bauxites of the weathering crust and in marine clayey sediments. The transfer of titanium is carried out in the form of mechanical fragments of minerals and in the form of colloids. Up to 30% TiO 2 by weight accumulates in some clays. Titanium minerals are resistant to weathering and form large concentrations in placers. More than 100 minerals containing titanium are known. The most important of them are: rutile TiO 2 , ilmenite FeTiO 3 , titanomagnetite FeTiO 3 + Fe 3 O 4 , perovskite CaTiO 3 , titanite CaTiSiO 5 . There are primary titanium ores - ilmenite-titanomagnetite and placer - rutile-ilmenite-zircon.

Place of Birth

Titanium deposits are located on the territory of South Africa, Russia, Ukraine, China, Japan, Australia, India, Ceylon, Brazil, South Korea, Kazakhstan. In the CIS countries, the Russian Federation (58.5%) and Ukraine (40.2%) take the leading place in terms of explored reserves of titanium ores. The largest deposit in Russia is Yaregskoye.

Reserves and production

In 2002, 90% of the mined titanium was used for the production of titanium dioxide TiO 2 . World production of titanium dioxide was 4.5 million tons per year. The confirmed reserves of titanium dioxide (without Russia) are about 800 million tons. For 2006, according to the US Geological Survey, in terms of titanium dioxide and excluding Russia, the reserves of ilmenite ores amount to 603-673 million tons, and rutile - 49, 7-52.7 million tons. Thus, at the current rate of production, the world's proven reserves of titanium (excluding Russia) will be enough for more than 150 years.

Russia has the world's second largest reserves of titanium after China. The mineral resource base of titanium in Russia consists of 20 deposits (of which 11 are primary and 9 are alluvial), fairly evenly dispersed throughout the country. The largest of the explored deposits (Yaregskoye) is located 25 km from the city of Ukhta (Komi Republic). The reserves of the deposit are estimated at 2 billion tons of ore with an average titanium dioxide content of about 10%.

The world's largest titanium producer is the Russian company VSMPO-AVISMA.

Receipt

As a rule, the starting material for the production of titanium and its compounds is titanium dioxide with a relatively small amount of impurities. In particular, it can be a rutile concentrate obtained during the beneficiation of titanium ores. However, the reserves of rutile in the world are very limited, and the so-called synthetic rutile or titanium slag, obtained during the processing of ilmenite concentrates, is more often used. To obtain titanium slag, ilmenite concentrate is reduced in an electric arc furnace, while iron is separated into a metal phase (cast iron), and not reduced titanium oxides and impurities form a slag phase. Rich slag is processed by the chloride or sulfuric acid method.

The concentrate of titanium ores is subjected to sulfuric acid or pyrometallurgical processing. The product of sulfuric acid treatment is titanium dioxide powder TiO 2 . Using the pyrometallurgical method, the ore is sintered with coke and treated with chlorine, obtaining a pair of titanium tetrachloride TiCl 4:

T i O 2 + 2 C + 2 C l 2 → T i C l 4 + 2 C O (\displaystyle (\mathsf (TiO_(2)+2C+2Cl_(2)\rightarrow TiCl_(4)+2CO)))

TiCl 4 vapors formed at 850 ° C are reduced with magnesium:

T i C l 4 + 2 M g → 2 M g C l 2 + T i (\displaystyle (\mathsf (TiCl_(4)+2Mg\rightarrow 2MgCl_(2)+Ti)))

In addition, the so-called FFC Cambridge process, named after its developers Derek Frey, Tom Farthing and George Chen, and the University of Cambridge where it was created, is now beginning to gain popularity. This electrochemical process allows direct continuous reduction of titanium from oxide in a melt mixture of calcium chloride and quicklime. This process uses an electrolytic bath filled with a mixture of calcium chloride and lime, with a graphite sacrificial (or neutral) anode and a cathode made from an oxide to be reduced. When a current is passed through the bath, the temperature quickly reaches ~1000–1100°C, and the calcium oxide melt decomposes at the anode into oxygen and metallic calcium:

2 C a O → 2 C a + O 2 (\displaystyle (\mathsf (2CaO\rightarrow 2Ca+O_(2))))

The resulting oxygen oxidizes the anode (in the case of using graphite), and calcium migrates in the melt to the cathode, where it restores titanium from oxide:

O 2 + C → C O 2 (\displaystyle (\mathsf (O_(2)+C\rightarrow CO_(2)))) T i O 2 + 2 C a → T i + 2 C a O (\displaystyle (\mathsf (TiO_(2)+2Ca\rightarrow Ti+2CaO)))

The resulting calcium oxide again dissociates into oxygen and calcium metal, and the process is repeated until the complete transformation of the cathode into a titanium sponge, or the exhaustion of calcium oxide. Calcium chloride in this process is used as an electrolyte to impart electrical conductivity to the melt and mobility of active calcium and oxygen ions. When using an inert anode (for example, tin oxide), instead of carbon dioxide, molecular oxygen is released at the anode, which pollutes the environment less, but the process in this case becomes less stable, and, in addition, under certain conditions, the decomposition of chloride becomes more energetically favorable, rather than calcium oxide, resulting in the release of molecular chlorine.

The resulting titanium "sponge" is melted down and purified. Titanium is refined by the iodide method or by electrolysis, separating Ti from TiCl 4 . To obtain titanium ingots, arc, electron beam or plasma processing is used.

Physical properties

Titanium is a light, silvery white metal. It exists in two crystalline modifications: α-Ti with a hexagonal close-packed lattice (a=2.951 Å; c=4.679 Å; z=2; space group C6mmc), β-Ti with cubic body-centered packing (a=3.269 Å; z=2; space group Im3m), transition temperature α↔β 883 °C, ΔH transition 3.8 kJ/mol. Melting point 1660 ± 20 °C, boiling point 3260 °C, density of α-Ti and β-Ti is respectively 4.505 (20 °C) and 4.32 (900 °C) g/cm³, atomic density 5.71⋅10 22 at/cm³ [ ] . Plastic, welded in an inert atmosphere. Resistivity 0.42 µOhm m at 20 °C

It has a high viscosity, during machining it is prone to sticking to the cutting tool, and therefore it is required to apply special coatings to the tool, various lubricants.

At normal temperature, it is covered with a protective passivating film of TiO 2 oxide, due to which it is corrosion-resistant in most environments (except alkaline).

Titanium dust tends to explode. Flash point - 400 °C. Titanium shavings are flammable.

Titanium, along with steel, tungsten, and platinum, is highly resistant to vacuum, which, along with its lightness, makes it very promising in the design of spacecraft.

Chemical properties

Titanium is resistant to dilute solutions of many acids and alkalis (except H 3 PO 4 and concentrated H 2 SO 4).

Easily reacts even with weak acids in the presence of complexing agents, for example, with hydrofluoric acid, it interacts due to the formation of a complex anion 2−. Titanium is most susceptible to corrosion in organic media, since, in the presence of water, a dense passive film of oxides and titanium hydride is formed on the surface of a titanium product. The most noticeable increase in the corrosion resistance of titanium is noticeable with an increase in the water content in an aggressive environment from 0.5 to 8.0%, which is confirmed by electrochemical studies of the electrode potentials of titanium in solutions of acids and alkalis in mixed water-organic media.

When heated in air to 1200°C, Ti ignites with a bright white flame with the formation of oxide phases of variable composition TiO x . Hydroxide TiO(OH) 2 ·xH 2 O precipitates from solutions of titanium salts, by careful calcination of which oxide TiO 2 is obtained. TiO(OH) 2 hydroxide xH 2 O and TiO 2 dioxide are amphoteric.

Application

In pure form and in the form of alloys

• Titanium in the form of alloys is the most important structural material in aircraft, rocket and shipbuilding.
• The metal is used in: chemical industry (reactors, pipelines, pumps, pipeline fittings), military industry (body armor, armor and fire barriers in aviation, submarine hulls), industrial processes (desalination plants, pulp and paper processes), automotive industry, agricultural industry, food industry, piercing jewelry, medical industry (prostheses, osteoprostheses), dental and endodontic instruments, dental implants, sporting goods, jewelry, mobile phones, light alloys, etc.
• Titanium casting is carried out in vacuum furnaces in graphite molds. Vacuum investment casting is also used. Due to technological difficulties in artistic casting, it is used to a limited extent. The first monumental cast titanium sculpture in the world is the monument to Yuri Gagarin on the square named after him in Moscow.
• Titanium is an alloying addition in many alloy steels and most special alloys [ what?] .
• Nitinol (nickel-titanium) is a shape memory alloy used in medicine and technology.
• Titanium aluminides are very resistant to oxidation and heat-resistant, which, in turn, determined their use in aviation and automotive industry as structural materials.
• Titanium is one of the most common getter materials used in high vacuum pumps.

In the form of connections

• White titanium dioxide (TiO 2 ) is used in paints (such as titanium white) as well as in the manufacture of paper and plastics. Food additive E171 .
• Organotitanium compounds (for example, tetrabutoxytitanium) are used as a catalyst and hardener in the chemical and paint industries.
• Inorganic titanium compounds are used in the chemical, electronic, glass fiber industries as additives or coatings.
• Titanium carbide, titanium diboride, titanium carbonitride are important components of superhard materials for metal processing.
• Titanium nitride is used to coat tools, church domes and in the manufacture of costume jewelry, as it has a color similar to gold.
• Barium titanate BaTiO 3, lead titanate PbTiO 3 and a number of other titanates are ferroelectrics.

There are many titanium alloys with different metals. Alloying elements are divided into three groups, depending on their effect on the temperature of polymorphic transformation: beta stabilizers, alpha stabilizers and neutral hardeners. The former lower the transformation temperature, the latter increase it, and the latter do not affect it, but lead to solution hardening of the matrix. Examples of alpha stabilizers: aluminum, oxygen, carbon, nitrogen. Beta stabilizers: molybdenum, vanadium, iron, chromium, nickel. Neutral hardeners: zirconium, tin, silicon. Beta stabilizers, in turn, are divided into beta-isomorphic and beta-eutectoid-forming.

The most common titanium alloy is the Ti-6Al-4V alloy (in the Russian classification - VT6).

Analysis of consumer markets

The purity and grade of rough titanium (titanium sponge) is usually determined by its hardness, which depends on the content of impurities. The most common brands are TG100 and TG110 [ ] .

Physiological action

As mentioned above, titanium is also used in dentistry. A distinctive feature of the use of titanium lies not only in strength, but also in the ability of the metal itself to grow together with the bone, which makes it possible to ensure the quasi-solidity of the tooth base.

isotopes

Natural titanium consists of a mixture of five stable isotopes: 46 Ti (7.95%), 47 Ti (7.75%), 48 Ti (73.45%), 49 Ti (5.51%), 50 Ti (5, 34%).

Artificial radioactive isotopes 45 Ti (T ½ = 3.09 h), 51 Ti (T ½ = 5.79 min) and others are known.

Notes

1. Michael E. Wieser, Norman Holden, Tyler B. Coplen, John K. Böhlke, Michael Berglund, Willi A. Brand, Paul De Bièvre, Manfred Gröning, Robert D. Loss, Juris Meija, Takafumi Hirata, Thomas Prohaska, Ronny Schoenberg, Glenda O'Connor, Thomas Walczyk, Shige Yoneda, Xiang‑Kun Zhu. Atomic weights of the elements 2011 (IUPAC Technical Report) (English) // Pure and Applied Chemistry. - 2013. - Vol. 85, no. 5 . - P. 1047-1078. - DOI:10.1351/PAC-REP-13-03-02 .
2. Editorial staff: Zefirov N. S. (editor-in-chief). Chemical Encyclopedia: in 5 volumes. - Moscow: Soviet Encyclopedia, 1995. - T. 4. - S. 590-592. - 639 p. - 20,000 copies. - ISBN 5-85270-039-8.
3. Titanium- article from the Physical Encyclopedia
4. J.P. Riley and Skirrow G. Chemical Oceanography V. 1, 1965
5. Deposit titanium.
6. Deposit titanium.
7. Ilmenite, rutile, titanomagnetite - 2006
8. Titanium (indefinite) . Information-analytical center "Mineral". Retrieved November 19, 2010. Archived from the original on August 21, 2011.
9. Corporation VSMPO-AVISMA
10. Koncz, St; Szanto, St.; Waldhauser, H., Der Sauerstoffgehalt von Titan-jodidstäben, Naturwiss. 42 (1955) pp.368-369
11. Titanium - metal of the future (Russian).
12. Titanium - article from the Chemical Encyclopedia
13. Influence water on process passivation titanium - 26 February 2015 - Chemistry and chemical technology in life (indefinite) . www.chemfive.ru Retrieved 21 October 2015.
14. Art casting in XX century
15. In the world market titanium for the last two months prices stabilized (review)

Links

• Titanium in the Popular Library of Chemical Elements

H He Li Be B C N O F Ne Na mg Al Si P S