The raw material for the production of titanium metals is mainly rutile, which contains more than 96% TiO 2. In countries without rutile, such as the Soviet Union, ilmenite “titanium slag” containing about 20% TiO 2 is used. Reserves are decreasing due to the increase in natural rutile. Countries tend to use ilmenite to produce titanium-rich materials such as high titanium slag and synthetic rutile.
Titanium was discovered in 1791, but the first pure titanium was manufactured in 1910 and has been in the middle for over 100 years. The reason is that titanium is very active at high temperatures and easily binds to oxygen, nitrogen, carbon and other elements. Extraction of pure titanium requires very harsh conditions.
Industrially, sulfuric acid is used to decompose ilmenite to produce titanium dioxide, and titanium dioxide is used to obtain titanium metal. Terrestrial ilmenite concentrated sulfuric acid (concentrate), next chemical reaction:
FeTiO3 + 3H2SO4 == Ti (SO4) 2 + FeSO4 + 3H2O
FeTiO3 + 2H2SO4 == TiOSO4 + FeSO4 + 2H2O
FeO + H2SO4 == FeSO4 + H2O
Fe2O3 + 3H2SO4 == Fe2 (SO4) 3 + 3H2O
In order to remove the impurity Fe2 (SO4) 3, iron scrap was added, Fe3 + was reduced to Fe2 +, the solution was cooled to 273K or less, and FeSO4.7H2O (green cerium) was crystallized as a by-product. .. ..
Water with Ti (SO4) 2 and TiOSO4 precipitated a white metatitanic acid precipitate. The reaction is as follows:
Ti (SO4) 2 + H2O == TiOSO4 + H2SO4
TiOSO4 + 2H2O == H2TiO3 + H2SO4
Preparation of titanium dioxide by calcination of metatitanic acid:
H2TiO3 == TiO2 + H2O
Titanium is manufactured industrially, and titanium tetrachloride is reduced by the metal fume fever reduction method. Mix TiO2 (or natural rutile) and charcoal powder at 1000-1100K. Chlorinated, obtained TiCl 4, steam condensed.
TiO2 + 2C + 2Cl2 = TiCl4 + 2CO
TiCl4 was reduced at 1070K with molten magnesium in argon to give a porous titanium sponge.
TiCl4 + 2Mg = 2MgCl2 + Ti
Titanium sponges were crushed and placed in a vacuum arc furnace to finally prepare various titanium materials.
You can also react as follows: Ti + 2CI2 = TiCI4
TiCI4 is obtained by high temperature decomposition (about 1250 degrees): TiCI4 = Ti + 2CI2
This gives a titanium rod.
Characteristics and applications of titanium and titanium alloys
Pure titanium is a silver-white metal with many excellent properties. Titanium has a density of 4.54 g / cm3, which is 43% lighter than steel. It’s a little heavier than magnesium. The mechanical strength is about the same as the strength of steel, the strength of steel is twice that of aluminum, and the strength of magnesium is five times that of magnesium. Titanium has high heat resistance and has a melting point of 1942K, which is about 1000K higher than gold and about 500K higher than steel.
Titanium is a more chemically active metal. When heated, it can also be used on non-metals such as O2, N2, H2, S and halogens. However, at room temperature, a very thin and dense oxide protective film is likely to be formed on the surface of titanium, which withstands the action of strong acid or aqua regia and exhibits strong corrosion resistance. Therefore, in general, metals are eroded in acid, alkali and salt solutions, but titanium is safe.
Liquid titanium dissolves almost all metals and can be alloyed with many metals. Titanium steel added to titanium steel is tough and elastic. Titanium and metals Al, Sb, Be, Cr, Fe and the like form gap compounds or intermetallic compounds.
Titanium aircraft weigh the same as other metal aircraft, but carry more than 100 passengers. The manufactured submarines are not only resistant to seawater corrosion, but also resistant to deep pressure. Its inundation depth is 80% higher than that of stainless steel submarines. At the same time, titanium is non-magnetic and is not found by land mines. It has a good anti-surveillance effect.
Titanium has “probiotic” properties. In the human body, it is resistant to erosion of secretions, is non-toxic and is suitable for any sterilization method. Therefore, it is widely used in the manufacture of medical devices. Artificial hip joints, knee joints, shoulder joints, lower limb joints, skulls, active heart valves, bone fixation clips. When new muscle fibers are wrapped around these “titanium bones,” these titanium bones begin to maintain normal human activity.
Titanium is widely distributed in the human body, and its normal human body content does not exceed 15 mg per 70 kg of body weight. The effect is not clear. However, titanium has been shown to stimulate phagocytes and enhance immunity.
Use of titanium compounds
Important titanium compounds are titanium dioxide (TiO2), titanium tetrachloride (TiCl4) and barium titanate (BaTiO3). Pure titanium dioxide is a white powder and is an excellent white pigment under the trade name “titanium dioxide”. It combines the long-lasting properties of white lead (PbCO3) and zinc white (ZnO). Therefore, titanium dioxide is often added to paints to produce fine white paints, such as pulp as a filler in the paper industry, as a matting agent for rayon in the textile industry, and as an additive in the glass, ceramic and enamel industries. Added to improve performance. Used as a catalyst in many chemical reactions. Today, with the development of the chemical industry, titanium dioxide and titanium compounds have high added value as fine chemical products, and the outlook is very attractive.
Titanium tetrachloride is a colorless liquid with a melting point of 250K, a boiling point of 409K, and a pungent odor. It is easily hydrolyzed in water or moist air and has a lot of white smoke.
TiCl4 + 3H2O == H2TiO3 + 4HCl
Therefore, TiCl4 is used as a military artificial aerosol and is used for maritime work. In agriculture, people use thick fog formed of TiCl4 to reduce heat loss at night and protect vegetables and crops from cold and frost.
Melting TiO2 and BaTiO3 to give titanate:
TiO2 + BaCO3 == BaTiO3 10 CO2
Artificially manufactured BaTiO 3 has a high dielectric constant, capacitors manufactured using it have a larger capacitance, and more importantly, BaTiO 3 has a remarkable “piezoelectric property”. Have. When the crystals are pressurized, they generate electricity. When you turn on the power, its shape changes. People put it in ultrasound and when it is pressurized it produces electricity. By measuring the current intensity, the intensity of ultrasonic waves can be measured. It is used in almost all ultrasonic measuring instruments. With the development and utilization of titanates, it is increasingly being used to produce non-linear components. Dielectric amplifiers, computer storage devices, microcapacitors, electroplating materials, aerospace materials, ferromagnetic materials, semiconductor materials, optical instruments, reagents, etc.
The excellent properties of titanium, titanium alloys and titanium compounds make them urgently needed. However, high manufacturing costs limit applications.
In the near future, we believe that the continuous improvement and improvement of titanium smelting technology will further advance the application of titanium, titanium alloys and titanium compounds.
Titanium and titanium alloys are very important lightweight structural materials and have very important applicability and wide applicability in the fields of aerospace, vehicle engineering and biomedical engineering.
Type: Titanium Iodine, Pure Industrial Titanium, Alpha Titanium, Beta Titanium, Alpha + Beta Titanium
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