eternal, mysterious, space, material of the future - all these and many other epithets assigned to the various sources of titanium.History of the discovery of this metal was not trivial: at the same time over the selected element in its pure form worked several scientists.The process of studying the physical and chemical properties and identification of areas of its application is not finished today.Titanium - the metal of the future, its place in human life not yet fully defined, giving modern researchers a huge scope for creativity and research.
Feature
chemical element titanium (Titanium) is designated in the periodic table of Mendeleev symbol Ti.Located in the side subgroup of Group IV of the fourth period and has a serial number 22. The simple substance of titanium - metal white-silver color, light and durable.The electronic configuration of the atom has the following structure: 22) 2) 8) 10) 2, 1S22S22P63S23P63d24S2.Consequently, titanium has several possible oxidation states 2, 3, 4, in the most stable compounds it is tetravalent.
Titanium - alloy or metal?
The issue of interest to many.In 1910, American chemist Hunter was the first pure titanium.Metal contained only 1% of impurities, but the amount is negligible, and it turned out made it impossible to further study its properties.The ductility of this material was achieved tolkopod high temperatures, under normal conditions (room temperature), the sample was too fragile.In fact, this item is not interested scientists since the prospects for its use seemed too vague.The complexity of obtaining and investigating further reduced the potential of its application.Only in 1925, chemists from the Netherlands J. de Boer and A. van Arkel received titanium metal, the properties of which have attracted the attention of engineers and designers throughout the world.The history of the study of this element begins with 1790, at this time, in parallel, independently from each other, the two scientists open titanium as an element.Each of them receives a compound (oxide) agent, failing to identify the metal in its purest form.Titanium is considered the discoverer of the English monk mineralogist William Gregor.On the territory of his parish, located in the southwestern part of England, a young scientist began studying black sand valley Menakena.The results of experiments with the magnet selection was brilliant grains, which is a compound of titanium.At the same time German chemist Martin Heinrich Klaproth identified the new substance from the mineral rutile.In 1797, he also proved that open parallel elements are similar.Titanium dioxide over a century, is a mystery to many chemists to obtain pure metal was not possible even Berzelius.Latest technologies of the XX century greatly accelerated the process of studying the said element and identified initial areas of its use.At the same time expanding the scope of the time.Limit the scope of its complexity of the process can only produce a substance such as pure titanium.The price of metal alloys and high enough, so today he can not displace the traditional iron and aluminum.
origin of the name
Menakin - the first name of titanium, which was used until 1795.That is, in the territorial jurisdiction, called the new element W. Gregory.Martin Klaproth assigns element in 1797 the name "Titan".At the time of his French colleagues, led by quite influential chemist AL Lavoisier offer to call the newly discovered substance in accordance with their basic properties.German scientist did not agree with this approach, he rightly believed that the discovery phase is quite difficult to define all the characteristics peculiar to the substance and be reflected in the title.However, we should recognize that user-selected Klaproth term is fully in line with the metal - it has repeatedly stressed the modern scientists.There are two main theories of the name Titan.Metal could be designated in honor of the elven queen Titania (Character Germanic mythology).This name symbolizes both lightness and durability matter.Most scientists are inclined to use Greek mythology, in which the Titans were called the sons of the mighty of the earth goddess Gaia.This version says the name of the previously open element - uranium.
Being in nature
of metals which technically are of value to humans, titanium occupies the fourth place in the extent of the earth's crust.Large proportion in nature are characterized only iron, magnesium and aluminum.The largest observed in the titanium content of basalt shell, a little less than it in a layer of granite.In sea water content of the substance is low - approximately 0.001 mg / l.Chemical element titanium is quite active, so pure it can not be found.In most cases, it is present in the compounds with the oxygen, thus has a valence of four.The amount of titanium minerals varies from 63 to 75 (from various sources), while at the present stage of research, scientists continue to discover new forms of its compounds.For practical use, the most important are the following minerals:
- Ilmenite (FeTiO3).
- Rutile (TiO2).
- Titanite (CaTiSiO5).
- Perovskite (CaTiO3).
- Titanomagnetite (FeTiO3 + Fe3O4) and so on. D.
All existing titanium-containing ore is divided into alluvial and basic.This element is a weak migrant, he can travel only in the form of stones or moving calving muddy bottom species.In the biosphere, the greatest amount of titanium contained in algae.The representatives of the terrestrial fauna element accumulates in the tissues of the horn, hair.For the human body characterized by the presence of titanium in the spleen, the adrenal glands, placenta, thyroid.
physical properties
Titanium - colored metal with silvery-white in color, looks like steel.At 0 0C has a density of 4.517 g / cm3.The substance has a low specific gravity, which is typical of the alkali metals (cadmium, sodium, lithium, cesium).Density titanium occupies an intermediate position between the 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 the yield strength and hardness.Titanium is stronger than aluminum 12 times, iron and copper - 4 times, while it is much easier.The ductility of the pure substance and its yield limit allow machining at high and low temperature values, as in the case of other metals, t. E. By riveting, forging, welding, rolling.The distinguishing characteristic of titanium - its low heat conductivity and, thus, these properties are retained at elevated temperatures up to 500 0C.The magnetic field is paramagnetic titanium element, it is not attracted as iron, and is not ejected as copper.Very high anti-corrosion performance in harsh environments and mechanical influences are unique.More than 10 years of being in the sea water did not change the appearance and composition of the titanium plates.Iron in this case would be totally destroyed by corrosion.
Thermodynamic properties of titanium
- Density (under normal conditions) is 4.54 g / cm3.
- Atomic number - 22.
- Group Metals - refractory, easy.
- atomic mass of titanium - 47.0.
- Boiling point (0C) - 3260.
- molar volume cm3 / mol - 10.6.
- melting point of titanium (0C) - 1668.
- Specific heat of evaporation (kJ / mol) - 422.6.
- electrical resistivity (at 20 0 C) Ohm * cm * 10-6 - 45.
chemical properties
increased corrosion resistance element due to the formation on the surface of the small oxide film.It prevents (under normal conditions) chemical reaction with gases (oxygen, hydrogen) located in the surrounding atmosphere of such elements as titanium metal.Its properties vary under the influence of temperature.With its increase up to 600 0C occurs reaction between oxygen, thereby forming a titanium oxide (TiO2).In the case of the absorption of atmospheric gases are formed fragile compounds which have no practical use for this reason welding and melting the titanium produced in the vacuum.Reversible reaction is the dissolution of hydrogen in the metal, it occurs more active at higher temperatures (400 0 C and above).Titanium, especially the fine particles (a thin plate or a wire), is burned in a nitrogen atmosphere.The chemical reaction between only possible at a temperature of 700 0C, thereby forming a nitride TiN.With many metals form high-hardness alloys often alloying element.The reaction with halogens (chrome, bromine, iodine) enters only in the presence of a catalyst (high temperature) and subject to interactions with a dry substance.This produces a very solid refractory alloys.With solutions of most alkalis and acids, titanium chemically active, exception is concentrated sulfuric (with prolonged boiling), hydrofluoric, hot organic (formic acid, oxalic acid).
deposits
most common in nature ilmenite ore - its reserves are estimated at 800 million tons.The deposits of rutile deposits are much more modest, but the total volume - while maintaining production growth - should provide humanity in the next 120 years, a metal such as titanium.The price of the final product will depend on the demand and increasing manufacturability, but on average ranges from 1200 to 1800 rubles. / Kg.With the continuous technical improvements significantly reduced the cost of all production processes in their timely upgrades.The largest reserves of titanium ore, China and Russia have also mineral base are Japan, South Africa, Australia, Kazakhstan, India, South Korea, Ukraine, Ceylon.Deposits of different production volumes and percentages of titanium ore, geological surveys are continuing constantly, which makes it possible to assume decrease the market value of the metal and its wider application.Russia is by far the largest producer of titanium.
Getting
for the production of titanium is most often used his dioxide containing a minimum amount of impurities.It is obtained by enrichment of ilmenite concentrates or rutile ores.The electric furnace heat treatment of ore occurs which is accompanied by the formation of iron and separation of slag containing titanium oxide.Sulfate or chloride method is used for the treatment of iron-free fractions.Titanium oxide is a gray powder (see. Photo).Titanium metal obtained by its processing phase.
The first phase is the process of sintering and coke slag with exposure to chlorine vapors.The resulting reduced TiCl4 with magnesium or sodium under temperature 850 0C.Titanium sponge (porous fused mass) resulting from a chemical reaction, purified, or melted down into ingots.Depending on further uses of formed metal alloy or pure (impurities are removed by heating to 1000 0 C).For the production of substances with a share of 0.01% of impurities used iodide method.It is based on the evaporation process of titanium sponge pretreated with halogen, its vapor.
Applications
melting point of titanium is high enough that the lightness of the metal is an invaluable advantage of using it as a structural material.Therefore, he finds the greatest application in the shipbuilding industry, the aviation industry, the manufacture of missiles, chemical production.Titanium is often used as a dopant in various alloys that exhibit improved characteristics of heat resistance and hardness.The high corrosion resistance and ability to withstand the most aggressive environments make this metal is indispensable for the chemical industry.Titanium (alloys) produced pipes, tanks, valves, filters, used for distillation and transportation of acids and other chemically active substances.He claimed to create devices operating at elevated temperature performance.The titanium compounds used to make durable cutting tools, paints, plastics and paper, surgical instruments, implants, jewelry, decorative materials, used in the food industry.All areas of hard to describe.Modern medicine for the full biological safety often uses metal titanium.Price - this is the only factor that influences is the breadth of application of this element.Justice is the assertion that the titanium - a material of the future, which is studying mankind enters a new stage of development.
