Titanium is a metal chemical element, chemical symbol Ti, atomic number 22, located in the fourth period, IVB group in the periodic table of chemical elements. It is a silver-white transition metal, which is characterized by light weight, high strength, metallic luster, and resistance to wet chlorine corrosion. But titanium cannot be used in dry chlorine. Even dry chlorine at a temperature below 0°C will undergo a violent chemical reaction to form titanium tetrachloride, which will then decompose to form titanium dichloride, or even burn. Only when the water content of the chlorine gas is higher than 0.5%, the titanium can maintain reliable stability in it.
Titanium is considered a rare metal because it is scattered in nature and difficult to extract. But it is relatively rich, ranking tenth among all elements. Titanium ore mainly includes ilmenite and rutile, which are widely distributed in the crust and lithosphere. Titanium also exists in almost all living things, rocks, water bodies and soil. The Kroll method or Hunter method is required to extract titanium from the main ore. The most common compound of titanium is titanium dioxide, which can be used to make white pigments. Other compounds include titanium tetrachloride (TiCl4) (used as a catalyst and used to make smoke screens as air cover) and titanium trichloride (TiCl3) (used to catalyze the production of polypropylene).
1. Gregor (Reverend William Gregor, 1762—1817): In 1791, titanium was discovered in Cornwall, England in the form of titanium-containing minerals. The discoverer was the English amateur mineralogist Gregor (Reverend William Gregor). ), who was working as a pastor in charge of the Diocese of Creed in Cornwall. He found some black sand by the creek in the neighbouring Manaccan parish. Later, he discovered that the sand would be attracted by magnets. He realized that this mineral (ilmenite) contains a new element. . After analysis, it was found that there were two metal oxides in the sand: iron oxide (the reason why sand is attracted by the magnet) and a white metal oxide that he could not identify. Realizing that this unidentified oxide contains an undiscovered metal, Gregor published the discovery to the Royal Geological Society of Cornwall and the German Annals of Chemistry. At about the same time, Franz-Joseph Müller von Reichenstein produced a similar substance, but could not identify it.
2. Klaproth (Martin Heinrich Klaproth, 1743-1817): In 1795, the German chemist Klaproth also discovered this oxide when analyzing red rutile produced in Hungary. He advocated adopting the method of naming uranium (discovered by Kraprot in 1789), citing the name of the Titanic tribe in Greek mythology, “Titanic”, and naming this new element “Titanium”. The Chinese name is Ti according to its transliteration. When he heard of Gregor’s earlier discovery, Klaprott obtained some samples of the Manacán mineral and confirmed that it contained titanium.
3. Hunter (Matthew A. Hunter): The titanium discovered by Gregor and Kraprot at the time was powdered titanium dioxide, not metallic titanium. Because the oxide of titanium is extremely stable, and metal titanium can directly and fiercely combine with oxygen, nitrogen, hydrogen, carbon, etc., elemental titanium is difficult to prepare. It was not until 1910 that the American chemist Hunter used sodium to reduce TiCl4 to produce titanium with a purity of 99.9%.
Development history abroad
In 1940, Luxembourg scientist W.J.Kroll used magnesium to reduce TiCl4 to obtain pure titanium. Since then, the magnesium reduction method (also known as the Kraul method) and the sodium reduction method (also known as the Hunter method) have become industrial methods for producing sponge titanium. The United States produced 2 tons of titanium sponge by the magnesium reduction method in 1948, and the industrial production of titanium has since begun.
In 1947, people began to smelt titanium in factories. That year, the output was only 2 tons. Production surged to 20,000 tons in 1955. In 1972, the annual output reached 200,000 tons. The yield strength of titanium is higher than that of steel, and its weight is almost only half of the same volume of steel. Although titanium is slightly heavier than aluminum, its yield strength is twice that of aluminum. The specific strength of titanium is higher than that of aluminum and steel, and the specific modulus is very close to that of aluminum and steel. In space rockets and missiles, large amounts of titanium are used instead of steel. According to statistics, the world’s annual titanium used for space navigation has reached more than 1,000 tons. Very fine titanium powder is also a good fuel for rockets, so titanium is known as cosmic metal and space metal.
Titanium easily reacts with air at high temperatures, but its melting point is as high as 1668°C. At normal temperature, titanium is not afraid of corrosion by aqua regia and dilute nitric acid, but it is not resistant to corrosion by sulfuric acid and 7% hydrochloric acid with a concentration of more than 5%. Titanium is not afraid of seawater at room temperature. Someone once sunk a piece of titanium to the bottom of the sea, and took it up five years later. There were many small animals and seabed plants stuck on it, but there was no rust at all, and it was still shiny.
People began to use titanium to make submarines-titanium submarines. Because titanium is very strong and can withstand high pressure, this submarine can sail in deep seas as deep as 4500 meters.
Domestic development history
China’s titanium industry started in the 1950s . In 1954, the Beijing Nonferrous Metals Research Institute began to conduct research on the preparation process of sponge titanium. In 1956, the country included titanium as a strategic metal in its 12-year development plan. A sponge titanium production workshop, and China’s first production trial workshop for titanium strip processing materials was established in the Shenyang non-ferrous metal processing plant.
In the 1960s and 1970s, under the unified national plan, more than 10 sponge titanium production units represented by Zunyi Titanium Factory were successively built; in 1967, China’s first titanium tube and rod processing plant was established in Luoyang Copper Processing Factory. The production test workshop and the second titanium strip production test workshop, and mainly undertook the trial production and development tasks of the first domestic nuclear submarine, the first guided missile destroyer and aviation titanium materials at that time, until the Baoji non-ferrous metal processing in 1972 After the plant was completed and put into production, Luoyang Copper Processing transferred the process data to the Beijing Nonferrous Research Institute. According to the division of the Ministry of Metallurgy, it no longer undertakes the development and trial production of titanium materials; the Beijing Nonferrous Research Institute, Shenyang Aluminum Magnesium Institute, and Fushun Aluminum Plant , Shenyang Nonferrous Metal Processing Plant, Northeast Light Alloy Processing Plant, Luoyang Copper Processing Plant, etc., assisted in the construction of Baoji Nonferrous Metal Processing Plant and Baoji Precious Metals Institute. Since then, according to the industry, Baoji Nonferrous Metals Processing Plant and Baoji Precious Metals Mainly, undertook the production, development and trial production of most of the domestic titanium processing materials. At the same time, China has also become the fourth country with a complete titanium industry system after the United States, the former Soviet Union and Japan.
Around 1980, the production of titanium sponge in China reached 2,800 tons. However, due to the lack of understanding of titanium metal by most people at that time, the high price of titanium materials also restricted the application of titanium. The output of titanium processed materials was only about 200 tons, and China’s titanium industry fell into Dilemma. Under such circumstances, initiated by the then Vice Premier of the State Council Fang Yi and supported by Zhu Rongji and Yuan Baohua, a cross-ministerial National Titanium Application Promotion Leading Group was established in July 1982 to coordinate the development of the titanium industry. From the 1980s to the early 1990s, the production and sales of China’s titanium sponge and titanium processed materials were booming, and the titanium industry was developing rapidly and steadily.
In summary, China’s titanium industry has roughly experienced three development periods: the pioneering period in the 1950s, the construction period in the 1960s and the 70s, and the initial development period in the 1980s and 1990s. In the new century, thanks to the sustained and rapid development of the national economy, China’s titanium industry has also entered a period of rapid growth.