Flammable/combustible material. May ignite on contact with moist air or moisture. May burn rapidly with flare-burning effect. Some react vigorously or explosively on contact with water. Some may decompose explosively when heated or involved in a fire. May re-ignite after fire is extinguished. Runoff may create fire or explosion hazard. Containers may explode when heated.
Titanium metal is very highly resistant to corrosion. It is unaffected by atmospheric air, moisture and sea water, allowing many of its industrial applications. The metal burns in air at about 1,200°C incandescently forming titanium dioxide TiO2. The metal also burns on contact with liquid oxygen. Titanium forms four oxides, all of which have been well described. It forms a weakly basic monoxide, TiO; a basic dititanium trioxide, Ti2O3; the amphoteric dioxide, TiO2; and the acidic trioxide, TiO3.
Titanium combines with nitrogen at about 800°C forming the nitride and producing heat and light. It is one of the few elements that burns in nitrogen. Titanium reacts with all halogens at high temperatures. It reacts with fluorine at 150°C forming titanium tetrafluoride, TiF4. Reaction with chlorine occurs at 300°C giving tetrachloride TiCl4. Bromine and iodine combine with the metal at 360°C forming their tetrahalides.
Water does not react with Ti metal at ambient temperatures, but tianium reacts with steam at 700°C forming the oxide and hydrogen:
Ti + 2H2O → TiO2 + 2H2
Titanium is soluble in hot concentrated sulfuric acid, forming sulfate. It also reacts with hydrofluoric acid forming the fluoride.
Nitric acid at ordinary temperatures does not react with Ti metal, but hot concentrated nitric acid oxidizes titanium to titanium dioxide.
The metal is stable with alkalies.
Titanium combines with several metals, such as, iron, copper, aluminum, chromium, cobalt, nickel, lead and tin at elevated temperatures forming alloys.
History, Occurrence and Uses
Titanium was discovered in 1790 by English chemist William Gregor. Five years later in 1795, Klaproth confirmed Gregor’s findings from his independent investigation and named the element titanium after the Latin name Titans, the mythical first sons of the Earth. The metal was prepared in impure form first by Nilson and Pettersson in 1887. Hunter, in 1910, prepared the metal in pure form by reducing titanium tetrachloride with sodium.
Titanium occurs in nature in the minerals rutile( TiO2), ilmenite (FeTiO3), geikielite, (MgTiO3) perovskite (CaTiO3) and titanite or sphene (CaTiSiO4(O,OH,F)). It also is found in many iron ores. Abundance of titanium in the earth’s crust is 0.565%. Titanium has been detected in moon rocks and meteorites. Titanium oxide has been detected in the spectra of M-type stars and interstellar space.
Titanium is found in plants, animals, eggs, and milk.
Many titanium alloys have wide industrial applications. Titanium forms alloys with a number of metals including iron, aluminum, manganese, and molybdenum. Its alloys are of high tensile strength, lightweight, and can withstand extreme temperatures. They are used in aircraft and missiles. The metal also has high resistance to sea water corrosion and is used to protect parts of the ships exposed to salt water. Also, titanium is used to combine with and remove traces of oxygen and nitrogen from incandescent lamps. Titanium compounds, notably the dioxide and the tetrachloride, have many uses (See Titanium Dioxide and Titanium Tetrachloride.)
As alloy with copper and iron in titanium bronze; as addition to steel to impart great tensile strength; to aluminum to impart resistance to attack by salt solutions and by organic acids; to remove traces of oxygen and nitrogen from incandescent lamps. Surgical aid (fracture fixation).
TITANIUM is a gray lustrous powder. TITANIUM can be easily ignited and burns with an intense flame. The very finely powdered material may be ignited by sparks.
dark grey lustrous solid
TITANIUM reacts violently with cupric oxide and lead oxide when heated. When titanium is heated with potassium chlorate, potassium nitrate, or potassium permanganate, an explosion occurs [Mellor 7:20. 1946-47]. The residue from the reaction of titanium with red fuming nitric acid exploded violently when the flask was touched [Allison 1969]. Liquid oxygen gives a detonable mixture when combined with powdered titanium, [Kirchenbaum 1956].
Flammable, dangerous fire and explosion
risk. (Metal) Ignites in air at 1200C, will burn in
atmosphere of nitrogen. Do not use water or carbon
dioxide to extinguish.
Metallic element of atomic
number 22, group IVB of the periodic table, aw
47.90, valences of 2, 3, 4; five isotopes
Air & Water Reactions
Highly flammable. Pyrophoric in dust form [Bretherick 1979, p. 104]. Titanium is water-reactive at 700C, releasing hydrogen, which may cause an explosion [Subref: Mellor, 1941, vol. 7, 19].
White lustrous metal; ductile when free of oxygen; low density high strength metal.
Titanium has two allotropic modifications: (1) alpha form and (2) beta modification. The alpha form has a close-packed hexagonal crystal structure; density 4.54 g/cm3 at 20°C and stable up to 882°C. It converts very slowly to a body-centered cubic beta form at 882°C. The density of the beta form is 4.40 g/cm3 at 900°C (estimated). The other physical properties are as follows: The metal melts at 1,610 ±10°C; vaporizes at 3,287°C; electrical resitivity 42 microhm-cm; modulus of elasticity 15.5x106 psi at 25°C; tensile strength, ultimate 34,000 psi (at 25°C); tensile strength yield 20,000 psi (at 25°C); Vickers hardness 80-100; surface tension at the melting point 1427dynes/cm3; superconductivity below 1.73°K; thermal neutron absorption cross section 5.8 barns; insoluble in water; soluble in dilute acids.
The production of titanium always encounters difficulties because of a tendency to react with oxygen, nitrogen and moisture at elevated temperatures. Most high purity elemental titanium can be produced by the Kroll process from titanium tetrachloride. The tetrachloride is reduced with magnesium in a mild steel vessel at about 800°C under an inert atmosphere of helium or argon. The net reaction is as follows:
TiCl4 + 2Mg → Ti + 2 MgCl2
The reaction is highly exothermic providing heat needed to maintain high temperature required for reaction. The Kroll process is applied commercially to produce elemental titanium.
Sodium metal can be used instead of magnesium in thermally reducing titanium tetrachloride.
Titanium metal also can be produced by electrolytic methods. In electrolysis, fused mixtures of titanium tetrachloride or lower chlorides with alkaline earth metal chlorides are electrolyzed to produce metal. Also, pure titanium can be prepared from electrolysis of titanium dioxide in a fused bath of calcium-, magnesium- or alkali metal fluorides. Other alkali or alkaline metal salts can be substituted for halides in these fused baths. Other titanium compouds that have been employed successfully in electrolytic titanium production include sodium fluotitanate and potassium fluotitanate.
Very highly pure titanium metal can be prepared in small amounts by decomposition of pure titanium tetraiodide, (TiI4) vapor on a hot wire under low pressure (Van Arkel–de Boer method).
Fire will produce irritating, corrosive and/or toxic gases. Inhalation of decomposition products may cause severe injury or death. Contact with substance may cause severe burns to skin and eyes. Runoff from fire control may cause pollution.