Zirconium and hafnium form compounds in the +4 oxidation state; titanium is also capable of forming compounds in the +3 oxidation state.
Compounds with oxidation state +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 in color. Titanium oxide is practically insoluble in water and exhibits basic properties. Oxide, chloride, Ti 3+ salts - strong reducing agents:
4Ti +3 Cl 3 + O 2 + 2H 2 O = 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)
With further heating, titanium(II) chloride also disproportionates:
2Ti +2 Cl 2 (t) = Ti 0 (t) + Ti +4 Cl 4 (g)
Compounds with oxidation state +4. Oxides of titanium(IV), zirconium(IV) and hafnium(IV) are refractory, chemically rather inert substances. They exhibit the properties of amphoteric oxides: they react slowly with acids during prolonged boiling and interact with alkalis during fusion:
TiO 2 + 2H 2 SO 4 = Ti(SO 4) 2 + 2H 2 O;
TiO 2 + 2NaOH = Na 2 TiO 3 + H 2 O
Titanium oxide TiO 2 is most widely used; 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) are 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 to obtain high-purity metals. For example:
TiI 4 = Ti + 2I 2
Fluorides of titanium, zirconium and hafnium are polymeric and low-reactive.
Salts elements of the titanium subgroup in the +4 oxidation state are few in number and hydrolytically unstable. Usually, when oxides or hydroxides react with acids, not intermediate salts are formed, but oxo- or hydroxo-derivatives. For example:
TiO 2 + 2H 2 SO 4 = TiOSO 4 + H 2 O; Ti(OH) 4 + 2HCl = TiOCl 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 are fluoride compounds:
EO 2 + 6HF = H 2 [EF 6 ] + 2H 2 O; EF 4 + 2KF = K 2 [EF 6 ]
Titanium and its analogues are characterized by coordination compounds in which the role of the ligand is played by the peroxide anion:
E(SO 4) 2 + H 2 O 2 = 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, which allows 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.
The discovery of TiO 2 was made almost simultaneously and independently of each other 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 named it titanium; later he established that rutile and menaken earth are oxides of the same element. The first sample of titanium metal was obtained in 1825 by J. Ya. Berzelius. A pure sample of Ti was obtained by the Dutchmen A. van Arkel and I. de Boer in 1925 by thermal decomposition of titanium iodide vapor TiI 4
Physical properties:
Titanium is a lightweight silvery-white metal. Plastic, weldable in an inert atmosphere.
It has a high viscosity and, during machining, is prone to sticking to the cutting tool, and therefore requires the application of special coatings to the tool and various lubricants.
Chemical properties:
At ordinary temperatures it is covered with a protective passivating film of oxide, 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 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 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 TiHx. When heated, these hydrides decompose, releasing H2.
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 . Amphoteric. In concentrated H 2 SO 4 dissolves only with prolonged heating. When fused with Na 2 CO 3 soda or K 2 CO 3 potash, TiO 2 oxide forms titanates:
TiO 2 + K 2 CO 3 = K 2 TiO 3 + CO 2
Titanium(IV) hydroxide, TiO(OH) 2 *xH 2 O, is precipitated from solutions of titanium salts; by carefully calcining it, TiO 2 oxide is obtained. Titanium(IV) hydroxide is amphoteric.
Titanium tetrachloride, TiCl 4 , under normal conditions, is a yellowish liquid that fumes strongly in air, which is explained by the strong hydrolysis of TiCl 4 by 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 H2 is formed, which is unknown in the free state; its Me 2 salts crystallize well and are stable in air.
By reducing 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- represents the interstitial phase with a wide region of homogeneity, crystals with a cubic face-centered lattice. Preparation - titanium nitriding at 1200 °C or 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, and osteoprostheses. It is the most important structural material in aircraft, rocket, and shipbuilding.
Titanium is an alloying additive in some grades of steel.
Nitinol (nickel-titanium) is an alloy with shape memory, 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 manufacturing 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.
Organo-titanium compounds (eg tetrabutoxytitanium) are used as a catalyst and hardener in the chemical and paint and varnish industries.
Inorganic titanium compounds are used in the chemical electronics and fiberglass industries as additives.
Matigorov A.V.
HF Tyumen State University
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Subtitles
Hi all! Alexander Ivanov is with you and this is the “Chemistry - Simple” project. And now we’ll have a little fun with titanium! This is what 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 what the main mineral from which titanium is extracted looks like. This is Rutile. In total, more than 100 minerals are known that 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 much had 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. Titan received its name from Klaproth, who named it in honor of the elven queen Titania. However, according to another version, the name of the element comes from the titans, the powerful sons of the earth goddess - Gays However, in 1797 it turned out that Gregor and Klaproth discovered the same chemical element. But the name remained the same as that given by Klaproth. But neither Gregor nor Klaproth were able to obtain the metal titanium. They received 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 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 of obtaining titanium and received several grams of pure 99% titanium. That is why in most books it is Hunter who is indicated as the scientist who received metal titanium. No one predicted a great future for titanium, since the slightest impurities in its composition made it very fragile and fragile, which did not allow mechanical testing processing Therefore, some titanium compounds found their widespread use earlier than 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. The fact that these are particles can be confirmed if we drop a few drops of titanium tetrachloride into water. Titanium tetrachloride is currently used to obtain metal titanium. The method for obtaining pure titanium has not changed for a hundred years. First, titanium dioxide is converted into titanium tetrachloride using chlorine, which we talked about earlier. Then, using magnesium thermia, 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 conditions of the reaction, we unfortunately do not have the opportunity to show this process The result is a titanium sponge, which is melted into a compact metal. To obtain ultra-pure titanium, they use the iodide refining method, which we will describe 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 trichloride titanium, then this is a purple solid. Just one less chlorine atom in the molecule, and already a different state. Titanium trichloride is hygroscopic. Therefore, you can only work with it in an inert atmosphere. Titanium trichloride dissolves well in hydrochloric acid. This is the process you are now observing. A complex ion is formed in the solution. 3– I’ll tell you what complex ions are next time. In the meantime, just be horrified :) If you add a little nitric acid to the resulting solution, titanium nitrate is formed and a brown gas is released, which is what we actually see. There is a qualitative reaction to titanium ions. Let's drop hydrogen peroxide. As you can see, a reaction occurs with the formation of a brightly colored compound This is supra-titanic acid. In 1908, in the USA, titanium dioxide began to be used for the production of white, which replaced white, which was based on lead and zinc. Titanium white greatly exceeded the quality of lead and zinc analogs. Also, titanium oxide was used to produce enamel, which was used for coatings of metal and wood in shipbuilding Currently, titanium dioxide is used in the food industry as a white dye - this is the E171 additive, which can be found in crab sticks, breakfast cereals, mayonnaise, chewing gum, dairy products, etc. Titanium dioxide is also used in cosmetics - it is part of the sun protection cream “All that glitters is not gold” - we have known this saying since childhood And in relation to the modern church and titanium, it works in the literal sense And it seems that what can be in common between the church and titanium? Here's what: all modern church domes that shimmer with gold actually have nothing to do with gold. In fact, all domes are coated with titanium nitride. Metal drills are also coated with titanium nitride. Only in 1925 was high-purity titanium 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 half the weight of iron, is superior in strength to many steels. 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-magneticity, titanium is of great interest in electrical engineering. Titanium has high resistance to corrosion. Due to its properties, titanium has become a material for space technology. In Russia, in Verkhnyaya Salda, there is the VSMPO-AVISMA corporation, which produces titanium for the global aerospace industry. From Verkhnyaya Salda titanium they make Boeings, Airbuses, Rolls-Royces, various chemical equipment and a lot of other expensive junk. However, each of you can buy a shovel or crowbar made of pure titanium! And it's not a joke! And this is how fine titanium powder reacts with atmospheric oxygen. Thanks to such colorful combustion, titanium has found application in pyrotechnics. And that’s all, subscribe, give a thumbs up, don’t forget to support the project and tell your friends! Bye!
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, which gave rise to the name “titanium” proposed by Klaproth. Ten years later, titanium was discovered 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 difficulty of its purification, a pure sample of Ti was obtained by the Dutchmen A. van Arkel and I. de Boer in 1925 by thermal decomposition of titanium iodide vapor TiI 4 .
origin of name
The metal got its name in honor of the titans, characters from 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 an element by its chemical properties. Since the German researcher himself noted the impossibility of determining the properties of a new element only from its oxide, he chose a name for it from mythology, by analogy with uranium he had previously discovered.
Being in nature
Titanium is in 10th place in terms of prevalence in nature. The content in the earth's crust is 0.57% by mass, in sea water - 0.001 mg/l. In ultramafic rocks 300 g/t, in basic rocks - 9 kg/t, in acidic rocks 2.3 kg/t, in clays and shales 4.5 kg/t. In the earth's crust, titanium is almost always tetravalent and is present only in oxygen compounds. Not found in free form. Under conditions of weathering and precipitation, titanium has a geochemical affinity with Al 2 O 3 . It is concentrated in bauxites of the weathering crust and in marine clayey sediments. Titanium is transported 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 ores - rutile-ilmenite-zircon.
Place of Birth
Titanium deposits are located in South Africa, Russia, Ukraine, China, Japan, Australia, India, Ceylon, Brazil, South Korea, and Kazakhstan. In the CIS countries, the leading places in explored reserves of titanium ores are occupied by the Russian Federation (58.5%) and Ukraine (40.2%). The largest deposit in Russia is Yaregskoye.
Reserves and production
As of 2002, 90% of mined titanium was used to produce titanium dioxide TiO 2 . World production of titanium dioxide was 4.5 million tons per year. Confirmed reserves of titanium dioxide (excluding Russia) are about 800 million tons. As of 2006, according to the US Geological Survey, in terms of titanium dioxide and excluding Russia, reserves of ilmenite ores amount to 603-673 million tons, and rutile ores - 49. 7-52.7 million tons. Thus, at the current rate of production, the world's proven reserves of titanium (excluding Russia) will last for more than 150 years.
Russia has the second largest reserves of titanium in the world, after China. The mineral resource base of titanium in Russia consists of 20 deposits (of which 11 are primary and 9 alluvial), fairly evenly distributed throughout the country. The largest of the explored deposits (Yaregskoye) is located 25 km from the city of Ukhta (Komi Republic). The deposit's reserves 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 from the enrichment of titanium ores. However, the reserves of rutile in the world are very limited, and the so-called synthetic rutile or titanium slag, obtained from 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 the metal phase (cast iron), and non-reduced titanium oxides and impurities form the slag phase. Rich slag is processed using the chloride or sulfuric acid method.
Titanium ore concentrate 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, producing titanium tetrachloride vapor 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)))The resulting TiCl 4 vapors are reduced with magnesium at 850 °C:
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 Fray, Tom Farthing and George Chen, and the University of Cambridge, where it was created, is now beginning to gain popularity. This electrochemical process allows for the direct, continuous reduction of titanium from its oxide in a molten 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 of a reducible oxide. When 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 reduces titanium from the 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 metallic calcium, and the process is repeated until the cathode is completely converted into a titanium sponge, or the calcium oxide is exhausted. In this process, calcium chloride 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, in some 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 cleaned. Titanium is refined using the iodide method or electrolysis, separating Ti from TiCl 4 . To obtain titanium ingots, arc, electron beam or plasma processing is used.
Physical properties
Titanium is a lightweight silvery-white metal. Exists in two crystal 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), temperature of the α↔β transition is 883 °C, ΔH of the transition is 3.8 kJ/mol. Melting point 1660±20 °C, boiling point 3260 °C, density of α-Ti and β-Ti respectively equal to 4.505 (20 °C) and 4.32 (900 °C) g/cm³, atomic density 5.71⋅10 22 at/cm³ [ ] . Plastic, weldable 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 requires the application of special coatings to the tool and various lubricants.
At ordinary temperatures it is covered with a protective passivating film of TiO 2 oxide, making it corrosion resistant in most environments (except alkaline).
Titanium dust tends to explode. Flash point - 400 °C. Titanium shavings are fire hazardous.
Titanium, along with steel, tungsten and platinum, is highly stable in a vacuum, which, along with its lightness, makes it very promising when designing 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).
It reacts easily even with weak acids in the presence of complexing agents, for example, it interacts with hydrofluoric acid due to the formation of a complex anion 2−. Titanium is most susceptible to corrosion in organic environments, since in the presence of water a dense passive film of titanium oxides and hydride is formed on the surface of a titanium product. The most noticeable increase in the corrosion resistance of titanium is noticeable when the water content in an aggressive environment increases 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 aqueous-organic media.
When heated in air to 1200 °C, Ti lights up with a bright white flame with the formation of oxide phases of variable composition TiO x. TiO(OH) 2 ·xH 2 O hydroxide is precipitated from solutions of titanium salts, and careful calcination of which produces TiO 2 oxide. Hydroxide TiO(OH) 2 xH 2 O and dioxide TiO 2 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 performed in vacuum furnaces into graphite molds. Vacuum lost wax casting is also used. Due to technological difficulties, it is used in artistic casting to a limited extent. The first monumental cast sculpture made of titanium in world practice is the monument to Yuri Gagarin on the square named after him in Moscow.
- Titanium is an alloying additive in many alloy steels and most special alloys [ which ones?] .
- 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 manufacturing 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 (eg titanium white) and in the production of paper and plastics. Food additive E171.
- Organo-titanium 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 electronics and fiberglass 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 instruments, church domes and in the production 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 the polymorphic transformation: beta stabilizers, alpha stabilizers and neutral strengtheners. The first ones lower the transformation temperature, the second ones increase it, the third ones do not affect it, but lead to solution strengthening 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 consumption markets
The purity and grade of rough titanium (titanium sponge) is usually determined by its hardness, which depends on the impurity content. 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 is not only its strength, but also the ability of the metal itself to fuse with the bone, which makes it possible to ensure the quasi-monolithic nature 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
- 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.
- Editorial team: Zefirov N. S. (chief editor). Chemical encyclopedia: in 5 volumes - Moscow: Soviet Encyclopedia, 1995. - T. 4. - P. 590-592. - 639 p. - 20,000 copies. - ISBN 5-85270-039-8.
- Titanium- article from the Physical Encyclopedia
- J.P. Riley and Skirrow G. Chemical Oceanography V. 1, 1965
- Titanium deposit.
- Titanium deposit.
- Ilmenite, rutile, titanomagnetite - 2006
- Titanium (undefined) . Information and analytical center "Mineral". Retrieved November 19, 2010. Archived August 21, 2011.
- VSMPO-AVISMA Corporation
- Koncz, St. Szanto, St.; Waldhauser, H., Der Sauerstoffgehalt von Titan-jodidstäben, Naturwiss. 42 (1955) pp.368-369
- Titanium is the metal of the future (Russian).
- Titanium - article from the Chemical Encyclopedia
- The influence of water on the passivation process of titanium - February 26, 2015 - Chemistry and chemical technology in life (undefined) . www.chemfive.ru. Retrieved October 21, 2015.
- The art of casting in the 20th century
- On the world titanium market, prices have stabilized over the last two months (review)
Links
- Titanium in the Popular Library of Chemical Elements
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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: several scientists simultaneously worked on isolating the element in its pure form. The process of studying 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 enormous scope for creativity and scientific research.
Characteristic
The chemical element is designated in D.I. Mendeleev’s periodic table by the symbol Ti. It is located in a secondary subgroup of group IV of the fourth period and has a serial number of 22. Titanium is a white-silver metal, light and durable. The electronic configuration of the 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 pure titanium for the first time. The metal contained only 1% impurities, but its amount turned out to be negligible and did not make it possible to further study its properties. The plasticity of the resulting substance was achieved only under the influence of high temperatures; under normal conditions (room temperature), the sample was too fragile. In fact, scientists were not interested in this element, since the prospects for its use seemed too uncertain. Difficulty in obtaining and researching has further reduced its potential for use. Only in 1925, chemists from the Netherlands I. de Boer and A. Van Arkel obtained 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, it was at this time that, in parallel, independently of each other, two scientists discovered titanium as a chemical element. Each of them receives a compound (oxide) of the substance, unable to isolate the metal in its pure form. The discoverer of titanium is considered to be the English mineralogist monk William Gregor. On the territory of his parish, located in the southwestern part of England, the young scientist began studying the black sand of the Menacan Valley. The result was the release of shiny grains, which were a titanium compound. At the same time, in Germany, 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; even Berzelius was unable to obtain pure metal. The latest technologies of the 20th century have significantly accelerated the process of studying this element and determined the initial directions for its use. At the same time, the scope of application is constantly expanding. Its scope can only be limited by the complexity of the process of obtaining such a substance as pure titanium. The price of alloys and metal is quite high, so today it cannot replace traditional iron and aluminum.
origin of name
Menakin was the first name for titanium, which was used until 1795. This is exactly what W. Gregor called the new element, based on its territorial affiliation. Martin Klaproth assigned the name "titanium" to the element in 1797. At this time, his French colleagues, led by the rather authoritative chemist A.L. Lavoisier, proposed naming 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 metal - this has been repeatedly emphasized by modern scientists. There are two main theories about the origin of the name titanium. The metal could have been designated this way in honor of the elven queen Titania (a character from German mythology). This name symbolizes both the lightness and strength of the substance. Most scientists are inclined to use the version of ancient Greek mythology, in which the mighty sons of the earth goddess Gaia were called titans. This version is also supported by the name of the previously discovered element - uranium.
Being in nature
Of the metals that are technically valuable to humans, titanium ranks fourth in terms of abundance in the earth's crust. Only iron, magnesium and aluminum have a high percentage in nature. The highest titanium content was 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 is impossible to find it in its pure form. Most often it is present in compounds with oxygen, and 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:
- Ilmenite (FeTiO 3).
- Rutile (TiO 2).
- Titanite (CaTiSiO 5).
- Perovskite (CaTiO 3).
- Titanium magnetite (FeTiO 3 + Fe 3 O 4), etc.
All existing titanium-containing ores are divided into placer and basic ores. This element is a weak migrant; it can only travel in the form of broken stones or the movement of silty bottom rocks. In the biosphere, the largest amount of titanium is found in algae. In representatives of terrestrial fauna, the element accumulates in horny tissues and hair. The human body is characterized by the presence of titanium in the spleen, adrenal glands, placenta, and thyroid gland.
Physical properties
Titanium is a non-ferrous metal with a silvery-white color that resembles steel in appearance. 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 characteristics are higher than those of both elements. The main properties of metals that 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, but it is much lighter. Its plasticity and yield strength allow it to be processed at low and high temperatures, as is the case with other metals, i.e., by riveting, forging, welding, and rolling methods. A distinctive characteristic of titanium is its low thermal and electrical conductivity, while these properties are retained 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 exposure to sea water did not change the appearance and composition of the titanium plate. In this case, the iron would be completely destroyed by corrosion.
Thermodynamic properties of titanium
- The density (under normal conditions) is 4.54 g/cm 3 .
- Atomic number - 22.
- Group of metals - refractory, lightweight.
- The atomic mass of titanium is 47.0.
- Boiling point (0 C) - 3260.
- Molar volume cm 3 /mol - 10.6.
- The melting point of titanium (0 C) is 1668.
- Specific heat of evaporation (kJ/mol) - 422.6.
- 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) found in the surrounding atmosphere of an element such as titanium metal. Its properties change under the influence of temperature. When it increases to 600 0 C, a reaction occurs with oxygen, resulting in the formation of titanium oxide (TiO 2). In the case of absorption of atmospheric gases, brittle compounds are formed that have no practical application, which is why welding and melting of titanium is carried out under vacuum conditions. A reversible reaction is the process of hydrogen dissolution in the metal; it occurs more actively with increasing temperature (from 400 0 C and above). Titanium, especially its small particles (thin plate or wire), burns in a nitrogen atmosphere. The chemical reaction is possible only at a temperature of 700 0 C, resulting in the formation of TiN nitride. It forms high-hard alloys with many metals and is often 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. Titanium is not chemically active with solutions of most alkalis and acids, with the exception of concentrated sulfuric acid (with prolonged boiling), hydrofluoric acid, and hot organic acids (formic acid, oxalic acid).
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 humanity with a metal such as titanium for the next 120 years. The price of the finished product will depend on demand and an increase in the level of manufacturability of production, but on average 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, and Ceylon also have mineral resource bases. The deposits differ in production volumes 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
To produce titanium, titanium dioxide is most often used, containing a minimal amount of impurities. It is obtained by enriching ilmenite concentrates or rutile ores. In an electric arc furnace, the ore is heat treated, which is accompanied by the separation of iron and the formation of slag containing titanium oxide. The sulfuric acid or chloride method is used to treat the iron-free fraction. Titanium oxide is a gray powder (see photo). Titanium metal is obtained by its step-by-step processing.
The first phase is the process of sintering 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). To produce a substance with an impurity fraction of 0.01%, the iodide method is used. It is based on the process of evaporating its vapors from a titanium sponge pre-treated with halogen.
Areas of application
The melting point 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 greatest use in shipbuilding, the aviation industry, rocket manufacturing, and chemical production. Titanium is often used as an alloying additive in various alloys that 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. Pipelines, containers, shut-off valves, and filters used in the distillation and transportation of acids and other chemically active substances are made from titanium (its alloys). It is in demand when creating devices operating at elevated temperatures. Titanium compounds are used to make durable cutting tools, paints, plastics and paper, surgical instruments, implants, jewelry, finishing materials, and used in the food industry. All directions are difficult to describe. Modern medicine often uses titanium metal due to complete biological safety. 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.
DEFINITION
Titanium located in the fourth period of group IV of the secondary (B) subgroup of the Periodic table. Designation – Ti. In its simple form, titanium is a silvery-white metal.
Refers to light metals. Refractory. Density - 4.50 g/cm3. The melting and boiling points are 1668 o C and 3330 o C, respectively.
Titanium is corrosion-resistant in air at ordinary temperatures, 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.).
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 equal to zero, since the distribution of electron density in them is uniform.
In its compounds, titanium is capable of exhibiting 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 | Nitrogen exhibits valency III and oxidation state (-3) in the compound: a) N 2 H 4 ; b) NH 3; c) NH 4 Cl; d) N 2 O 5 |
| Solution | In order to give the correct answer to the question posed, we will alternately determine the valency and oxidation state of nitrogen in the proposed compounds. a) the valence of hydrogen is always equal to I. The total number of units of valence of hydrogen is equal to 4 (1 × 4 = 4). Let us divide the obtained value by the number of nitrogen atoms in the molecule: 4/2 = 2, therefore, the valency of nitrogen is II. This answer option is incorrect. b) the valence of hydrogen is always equal to I. The total number of units of hydrogen valence is equal to 3 (1 × 3 = 3). Let us divide the obtained value by the number of nitrogen atoms in the molecule: 3/1 = 2, therefore, the valency of nitrogen is III. The oxidation degree 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. |
| Solution | In order to give the correct answer to the question posed, we will alternately determine the oxidation state of chlorine in each pair of proposed compounds. a) The oxidation state of iron is (+3), and that of oxygen is (-2). Let us 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 us 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). |
