Titanium is considered a rare metal because it is dispersed in nature and difficult to extract. But it is relatively abundant, ranking tenth among all elements. Titanium ores are mainly ilmenite and rutile, widely distributed in the crust and lithosphere. Titanium is also present in almost all living things, rocks, water and soil. The extraction of titanium from primary ores requires either the Crohl or Hunter processes. The most common compound of titanium is titanium dioxide, which can be used to make white pigments. Other compounds include titanium tetrachloride (TiCl4), which is used as a catalyst and to create smoke screens for air cover, and titanium trichloride (TiCl3), which is used to catalyze the production of polypropylene.
Titanium is easy to react with air at high temperatures, but the melting point is as high as 1668 ℃. At room temperature, titanium is not afraid of aqua regia and dilute nitric acid corrosion, but is not resistant to more than 5% sulfuric acid corrosion and 7% hydrochloric acid corrosion. Titanium is not afraid of normal temperature sea water, someone has sunk a piece of titanium to the bottom of the sea, five years later to take a look, it is glued to many small animals and seabed plants, but there is no rust, still shiny.
Titanium can be fused with other elements such as iron, aluminum, vanadium or molybdenum to form high-strength light alloys, which have a wide range of applications. These include aerospace (jet engines, missiles and spacecraft), military, industrial processes (chemicals and petroleum products, desalination and paper), automotive, agro-food, medicine (prosthetics, orthopaedic implants and dental instruments and fillings), sporting goods, jewellery and mobile phones.
Two of titanium's most useful properties are corrosion resistance and the highest strength-to-weight ratio of any metal. In its non-alloyed state, titanium is as strong as some steels, but 45% lighter.There are two allotropes and five natural isotopes, from Ti to Ti, the most abundant of which is Ti(73.8%). The chemical and physical properties of titanium are similar to those of zirconium because they have the same number of valence electrons and belong to the same family in the periodic table.
