Titanium Smelting

The raw material for the production of titanium metal is mainly rutile, which contains more than 96% TiO2. Lack of rutile ore countries, such as the Soviet Union, the use of ilmenite made of "high titanium slag", which contains about 90% TiO2. In recent years, due to the price of natural rutile and dwindling reserves, countries tend to use ilmenite made of titanium-rich materials, that is, high titanium slag and artificial rutile.

Titanium was discovered in 1791, but the first time to make pure titanium is in 1910, the middle of more than a hundred years. The reason is: titanium is very active at high temperatures, it is easy to combine with oxygen, nitrogen, carbon and other elements, to extract pure titanium requires very harsh conditions.

Industry commonly used sulfuric acid decomposition of ilmenite titanium dioxide, titanium dioxide from titanium metal titanium. Concentrated sulfuric acid treatment of ground ilmenite (concentrate), the following chemical reaction occurs:

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 filings are added and Fe3+ is reduced to Fe2+, then the solution is cooled to below 273K, allowing FeSO4-7H2O (green alum) to crystallize as a by-product.

The hydrolysis of Ti(SO4)2 and TiOSO4 precipitated a white metatitanate precipitate, the reaction was:

Ti(SO4)2+H2O == TiOSO4+H2SO4

TiOSO4+2H2O == H2TiO3+H2SO4

Titanium dioxide is produced by forging metatitanic acid:

H2TiO3 == TiO2+H2O

Industrial production of titanium metal using metal thermal reduction method to reduce titanium tetrachloride. TiO2 (or natural rutile) and charcoal powder mixture heated to 1000 ~ 1100K, chlorination, and make the generation of TiCl4, vapor condensation.

TiO2+2C+2Cl2=TiCl4+2CO-

Reduction of TiCl4 with molten magnesium in argon at 1070K gives porous titanium sponge:

TiCl4+2Mg=2MgCl2+Ti

This titanium sponge is crushed, melted in a vacuum arc furnace and finally made into various titanium materials.

It is also possible to react: Ti+2I2=TiI4

The TiI4 obtained is decomposed at high temperature (around 1250°C):

TiI4=Ti+2I2

This results in pure titanium rods.

Properties and uses of titanium and titanium alloys

Pure titanium is a silver-white metal, which has many excellent properties. The density of titanium is 4.54g/cm3, 43% lighter than steel, and slightly heavier than the prestigious light metal magnesium. Mechanical strength is similar to steel, twice as large as aluminum, five times larger than magnesium. Titanium is resistant to high temperatures, melting point 1942K, nearly 1000K higher than gold, nearly 500K higher than steel.

Titanium belongs to the more active chemical properties of the metal. When heated with O2, N2, H2, S and halogens and other non-metallic role. But at room temperature, titanium surface is easy to generate a very thin layer of dense oxide protective film, can resist the role of strong acids and even aqua regia, showing strong corrosion resistance. Therefore, the general metal in the acid, alkali, salt solution becomes full of holes and titanium is safe and sound.

Liquid titanium can dissolve almost all metals, so it can form alloys with a variety of metals. Titanium is added to steel to produce titanium steel, which is tough and flexible. Titanium and metal Al, Sb, Be, Cr, Fe, etc. to generate gap-filling compounds or intermetallic compounds.

Titanium alloy made of aircraft than other metals made of the same weight of the aircraft more than 100 passengers. Made of submarines, both seawater corrosion resistance, but also resistance to deep pressure, its dive depth than stainless steel submarines increased by 80%. At the same time, titanium is non-magnetic, will not be found by mines, has a very good anti-guardian role.

Titanium has a "pro-biotic" 'sex. In the human body, it can resist the corrosion of secretion and non-toxic, and it is adaptable to any sterilization method. Therefore, it is widely used in the production of medical equipment, the production of artificial hip joints, knee joints, shoulder joints, joints, coercive joints, skull, active heart valves, bone fixation clips. When the new muscle fiber ring wrapped in these "titanium bones", these titanium bones began to maintain the normal activities of the human body.

Titanium is widely distributed in the human body, and the normal human body content is not more than 15mg per 70kg of body weight, and its role is still unclear. However, titanium can stimulate phagocytes, so that the role of immunity has been confirmed.

Titanium compounds and uses

Important titanium compounds include: titanium dioxide (TiO2), titanium tetrachloride (TiCl4), and barium metatitanate (BaTiO3).

Pure titanium dioxide is white powder, is an excellent white pigment, the trade name "titanium dioxide". It has both the covering performance of lead white (PbCO3) and the lasting performance of zinc white (ZnO). Therefore, people often add titanium dioxide in paint, made of high-grade white paint; in the paper industry as a filler added to the paper paddle; textile industry as a matting agent for artificial fibers.

In the textile industry as a matting agent for man-made fibers; in the glass, ceramics, enamel industry as an additive to improve its performance; used as a catalyst in many chemical reactions. In the chemical industry is increasingly developing today, titanium dioxide and titanium compounds as fine chemical products, has a high added value, the prospect is very attractive.

Titanium tetrachloride is a colorless liquid; melting point of 250K, boiling point of 409K, with the system of excitatory odor. It is easy to hydrolyze in water or humid air and emits a lot of white smoke.

TiCl4+3H2O == H2TiO3+4HCl

Therefore, TiCl4 is used in the military as an artificial smoke agent, as if it were used in maritime warfare. In agriculture, people use TiCl4 to form a dense fog ground to reduce the loss of heat from the ground at night, and to protect vegetables and crops from the harm of cold and frost.

Barium metatitanate is made by melting TiO2 and BaCO3 together:

TiO2+BaCO3 == BaTiO3 ten CO2-

Artificially produced BaTiO3 has a high dielectric constant, made of capacitors have a larger capacity, more importantly, BaTiO3 has significant "piezoelectric properties", the crystal pressure will produce current, a power, and will change shape. People put it in the ultrasonic wave, it is pressurized to produce current, by measuring the current strength can be measured ultrasonic strength. Almost all of the ultrasonic instruments have to use it. With the development and utilization of titanate, it is more and more widely used in the manufacture of non-linear components, dielectric amplifiers, electronic computer memory components, micro-capacitors, electroplating materials, aerospace materials, strong magnetic, semiconductor materials, optical instruments, reagents and so on.

The excellent properties of titanium, titanium alloys and titanium compounds have led to an urgent need for them. However, the high cost of production has limited their application. We believe that in the near future, with the continuous improvement and enhancement of titanium smelting technology, the application of titanium, titanium alloys and titanium compounds will be more developed.

Titanium products:

Titanium and titanium alloys are extremely important lightweight structural materials with very important application value and broad application prospects in aviation, aerospace, vehicle engineering, biomedical engineering and other fields.

Types: titanium canonization, industrially pure titanium, α-type titanium, β-type titanium, α + β-type titanium