Titanium

Titanium (Ti)

Introduction

Titanium is a chemical element with the atomic number 22 in the periodic table. After aluminum, iron, and magnesium, titanium is the fourth most abundant metal that occurs in Earth’s structural layers. As a member of the transition metals family of periodic table elements, titanium has four valence electrons.

 

Being classified as a non-toxic and safe substance with strong anti-corrosive properties, titanium is widely used for making medical and dental implants, in marine and space industries, as well as in cosmetics.  

Fact Box

Chemical and Physical Properties of Titanium

The symbol in the periodic table of elements: Ti

Atomic number: 22

Atomic weight (mass): 47.90 g.mol-1

Group number: 4 (Transition metals)

Period: 4 (d-block)

Color: A silvery-white metallic color

Physical state: Solid at room temperature

Half-life: From less than 120 nanoseconds to 60 years

Electronegativity according to Pauling: 1.5

Density: 4.506 g.cm-3 at 20°C

Melting point: 1670°C, 3038°F, 1943 K

Boiling point: 3287°C, 5949°F, 3560 K

Van der Waals radius: 0.147 nm

Ionic radius: 0.09 nm (+2) ; 0.068 nm (+4)

Isotopes: 25

Most characteristic isotope: 48Ti

Electronic shell: [Ar] 3d24s2

The energy of the first ionization: 658 kJ.mol-1

The energy of the second ionization: 1310 kJ.mol-1

The energy of the third  ionization: 2652 kJ.mol-1

The energy of the fourth ionization: 4175 kJ.mol-1

Discovery date: In 1791 by William Gregor

 

With the periodic table symbol Ti, atomic number 22, atomic mass of 47.90 g.mol-1, and electron configuration [Ar] 3d24s2, titanium is a chemical of an extremely high strength which is also light, ductile, flexible, and malleable. It has a lower specific density than stainless steel but possesses the same strength and hardness. 

 

This nonmagnetic and corrosion-resistant metal has a characteristic silvery-white metallic color and low density. It reaches its boiling point at 3287°C, 5949°F, 3560 K, while the melting point is achieved at 1670°C, 3038°F, 1943 K. Classified as a member of the transition metals family of elements in the periodic table, titanium has an electronegativity of 1.5 according to Pauling, whereas the atomic radius according to van der Waals is 0.147 nm. 

 

Titanium is classified in the first transition group of the periodic table since the chemical properties of element 22 resemble the chemical behavior of the elements silica and zirconium. When titanium adopts lower oxidation states, it displays similar chemical properties to the elements chrome and vanadium. 

 

Upon exposure to oxygen, pure titanium forms a prospective layer of ceramic that resembles an oxide film. This chemical reaction supports the high corrosion resistance of this transition metal. It’s also insoluble in water but readily dissolved in concentrated acids.                      

How Was Titanium Discovered?

Reverend William Gregor (1761 – 1817) from Cornwall, England, is the first person to have pointed out titanium as a new chemical element. In 1791, Gregor succeeded in extracting an impure titanium oxide from the black, gunpowder-like magnetic sand that he obtained from a stream in the parish of Manaccan. 

 

In his experiment, Gregor dissolved the black powder in acid, which resulted in a colorless solution. In the next step of the experiment, this advanced transition metal chemist reduced the colorless solution by zinc to a purple solution. At the end of the chemical trial, Gregor observed two distinct substances that made up the black powder – one of them was magnetite (Fe3O4), while the other reddish-brown substance was identified as an impure oxide of the new metallic chemical element manaccanite, i.e. titanium (Ti). 

The Contribution of Martin Heinrich Klaproth 

In 1795, the renewed German chemist Martin Heinrich Klaproth analyzed a sample of the mineral rutile, obtained from Boinik, Hungary. After extensive observation, Klaproth was sure that the red oxide was, in fact, an unknown element which he labeled as titanium. Upon revision of Gregor’s discovery, Klaproth also observed that he had derived the same red manaccanite oxide as Gregor did back in 1791. 

The Contribution of Matthew Hunter

Discovering the new chemical element with atomic mass 22 proved to be much easier than its pure-form isolation. After many unsuccessful attempts of the scientists over a span of more than 100 years, the New York-based metallurgist Matthew Hunter managed to do the seemingly impossible thing – isolate the titanium metal. By heating titanium (IV) chloride with sodium to red-heat in a pressure cylinder, Hunter produced the metallic form of the element 22. Today, this process is labeled as the Kroll Process and is applied in the commercial production of titanium.

How Did Titanium Get Its Name?

The original name of element 22 was ‘manaccanite’. It was derived from the name of a village in South Cornwall of the United Kingdom called Manaccan. This village was the place where pastor William Gregor first discovered titanium in 1791. 

 

After the amazing physical and chemical properties of the new chemical were determined, element 22 got the name ‘titanium’ after the Titans – the strong sons of the Earth goddess described in Greek mythology.

Where Can You Find Titanium?

With an occurrence of about 0.6% in the Earth’s crust, titanium is a chemical element that is always bonded to other chemicals found in nature. It typically occurs in igneous rocks and their sediments. The element 22 can also be traced in all living things, as well as in the surface waters. Titanium oxide bands have been observed in spectra of M-type stars, the Sun, some types of meteorites, coal ash, plants, as well as in the human body.

 

Minerals ilmenite (FeTiO3) and rutile (TiO2) are often mined for the rich concentration of titanium in them. This chemical element is also found in the minerals anatase, perovskite, brookite, ilmenite, rutile, and titanite (sphene). 

 

The most significant ilmenite and rutile deposits are located in Eastern and Western Australia, Canada, the eastern coast of America, New Zealand, Brazil, Mozambique, South Africa, India, Norway, Ukraine, China, and Sierra Leone. On the other hand, Australia and the United States are considered countries rich in titanium placer minerals. 

 

About 95% of titanium production all over the world is in the form of titanium dioxide (titania). Pure titanium metal is shaped into sheets, billets, ingots, plates, pipes, forgings, blocks, bars, fasteners, or tubings ready for further industrial processing.

List of Titanium Minerals

There are more than 140 minerals that have been identified and known for their richness in titanium. However, about ten of them are actively exploited for the extraction of element 22. The following is an exhaustive list of the titanium minerals:


  • Achalaite
  • Aenigmatite
  • Aeschynite-(Y)
  • Akaogiite
  • Alluaivite
  • Alsakharovite-Zn
  • Altisite
  • Anatase
  • Andradite
  • Anzaite-(Ce)
  • Armalcolite
  • Asbecasite
  • Aspedamite
  • Azoproite
  • Benitoite
  • Betafite
  • Brookite
  • Cafetite
  • Cleusonite
  • Dualite
  • Euxenite
  • Faizievite
  • Ferri-obertiite
  • Geikielite
  • Grossmanite
  • Haggertyite
  • Heavy mineral sands ore deposits
  • Ilmenite
  • Jinshajiangite
  • Keilhauite
  • Labyrinthite
  • Lorenzenite
  • Loveringite
  • Nabalamprophyllite
  • Nenadkevichite
  • Neptunite
  • Pabstite
  • Panguite
  • Perovskite
  • Polycrase
  • Pyrophanite
  • Rutile
  • Sabinaite
  • Schreyerite
  • Tausonite
  • Tistarite
  • Titanite
  • Titanoholtite
  • Titanowodginite
  • Warwickite
  • Wassonite
  • Zimbabweite
  • Zirconolite
  • Zircophyllite
  • Zirkelite
  • Zorite

 

Titanium in Everyday Life

The metallurgical characteristics of titanium make this transition metal a component of choice for many branches of scientific, economic, or commercial activity – from the aerospace industry to consumer goods industries: 

 

  • Titanium is widely used as an alloying agent. Titanium alloys (with metals like aluminum, molybdenum, vanadium, nickel, zirconium, copper, and iron) are used for their low density, corrosion resistance, and resistance to high temperatures in aircraft, naval ships, spacecraft, golf clubs, laptops, bicycles, crutches, and missiles;
  • The anti-corrosive properties and the toughness of titanium make this substance one of the most widely used in medicine. Namely, titanium is extensively applied in the production of hip and knee implants, dental implants and fixation systems, craniofacial plates, pacemaker cases, and other similar medical aids. The fact that titanium can osseointegrate, i.e. the bone can grow into the titanium implant, only adds to the firmness and strength of this metal;
  • Titanium dioxide (TiO2) has a wide application as a white pigment with an excellent coating power. This titanium powder also adds brightness, hardness, and acid resistance to the porcelain enamels used in dentistry. This naturally occurring white powder is often used in the making of makeup, such as lipsticks, suntan lotions, soap bars, and toothpaste. It adds shimmer, supports the UV protection, and brightens the skin;
  • Titanium alloys are often a substance of choice for building firewalls, hydraulic systems, exhaust ducts, wave soldering, ultrasonic welding, and landing gear. Some of these titanium alloys have even higher tensile strengths than titanium itself does;
  • Sporting equipment made with titanium is lightweight and durable. This metal is frequently used in the manufacturing of bicycle components, lacrosse and hockey helmet grills, golf clubs, as well as tennis rackets;
  • Titanium tetrachloride (TiCl4) is not only an excellent catalyst but also a great agent for smoke screens and skywriting;
  • Titanium dioxide paint is commonly used in solar observatories due to its excellent UV reflective properties;
  • Due to the excellent anti-corrosive properties which are unaffected even by the saline seawater, titanium metal is used in desalination plants, as well as to protect the hulls of ships, submarines, and other structures exposed to seawater;
  • Nuclear waste is typically stored in titanium-made containers, which signifies the durability, strength, and resistance of this chemical;
  • As a strengthening agent, titanium is used in gemstones, cement, graphite composite fishing rods, and golf clubs;
  • Sometimes, a low amount of titanium is added to the gold jewelry in order to increase the strength of the metal item.

How Dangerous Is Titanium?

The pure, elemental form of titanium is not classified as a mutagenic or carcinogenic substance. It also has low toxicity. On the contrary, it’s a non-magnetic, non-toxic, and non-allergenic substance. However, titanium’s metallic powder may pose a significant explosion and fire hazard. 

 

Being classified as a heavy metal, titanium may also lead to some serious health problems if it’s swallowed, ingested, or inhaled in the form of dust. In such cases, this substance may trigger severe bouts of cough, chest pain with tightness, breathing difficulties, and eventually lead to pleural disease. In addition, the metallic dust particles can lead to irritation of eyes or lungs upon contact or inhalation. 

What Are the Symptoms of Titanium Toxicity?

The most commonly occurring symptoms and adverse effects of titanium toxicity include:

 

  • Eczema (upon prolonged skin contact with the metal titanium);
  • Chronic inflammation of the kidneys;
  • Problems with breathing;
  • Various lung diseases;
  • Problems with the eyesight;
  • Irritation of the mucous membranes;
  • Irritation of the eyes;
  • Lupus.

 

Since the titanium accumulations in the body’s tissues and organs often deplete the silica concentrations, silica deficiency may alert an excess concentration of titanium in the human body. 

 

Despite being considered as a safe material, titanium toxicity may occur after a medical or dental implantation made of titanium as well as occupational exposure or prolonged use of sunscreen lotions with high concentrations of Ti. 

Environmental Effects of Titanium

Being widely spread in nature, titanium is not considered to have any negative environmental impact. On the contrary, titanium is one of the most environmentally friendly metals. Its low weight contributes to indirectly lowering environmental pollution since the low weight of cars, aircrafts, and ships made with this substance also lowers the fuel consumption.

Titanium Dioxide Pollution

TiO2 (titanium dioxide) is frequently added to sunscreen lotions as an agent that forms a layer of skin protection against the Sun’s harmful UV rays. But, since the protective coating of the titanium nanoparticles in the sunscreen lotions dissolve in water, the river, lake, sea, and ocean waters become contaminated by the bathers protecting themselves from the sun on the beaches. 

 

The researchers of this highly alarming environmental issue warn of titanium dioxide as a pollutant that we need to be aware of, as well as that we must put in greater efforts to lower the TiO2 in the seawater. The presence of titanium dioxide in the surface waters not only pollutes the aquatic systems, but also harms marine life, the coral reefs, and – eventually – us. 

Isotopes of Titanium

There are 25 isotopes of titanium with atomic mass ranging from titanium-38 to titanium-63. Naturally occurring titanium (22Ti) is made up of five stable isotopes: 46Ti, 47Ti, 48Ti, 49Ti, and 50Ti.

With 73.8% natural abundance, the 48Ti is the most abundant form of titanium. 

 

Among the 21 radioactive isotopes of titanium that have been identified, the 44Ti is the most stable radioactive form of this chemical element. Having a half-life of 60 years, the titanium-44 isotope is also the longest living form of element 22. 

 

Nuclide

[n 1]

Z N Isotopic mass (Da)

[n 2][n 3]

Half-life

[n 4]

Decay

mode

[n 5]

Daughter

isotope

[n 6]

Spin and

parity

[n 7][n 4]

Natural abundance (mole fraction)
Excitation energy Normal proportion Range of variation
38Ti 22 16 38.00977(27)# <120 ns 2p 36Ca 0+
39Ti 22 17 39.00161(22)# 31(4) ms

[31(+6-4) ms]

β+, p (85%) 38Ca 3/2+#
β+ (15%) 39Sc
β+, 2p (<.1%) 37K
40Ti 22 18 39.99050(17) 53.3(15) ms β+ (56.99%) 40Sc 0+
β+, p (43.01%) 39Ca
41Ti 22 19 40.98315(11)# 80.4(9) ms β+, p (>99.9%) 40Ca 3/2+
β+ (<.1%) 41Sc
42Ti 22 20 41.973031(6) 199(6) ms β+ 42Sc 0+
43Ti 22 21 42.968522(7) 509(5) ms β+ 43Sc 7/2−
44Ti 22 22 43.9596901(8) 60.0(11) y EC 44Sc 0+
45Ti 22 23 44.9581256(11) 184.8(5) min β+ 45Sc 7/2−
46Ti 22 24 45.9526316(9) Stable 0+ 0.0825(3)
47Ti 22 25 46.9517631(9) Stable 5/2− 0.0744(2)
48Ti 22 26 47.9479463(9) Stable 0+ 0.7372(3)
49Ti 22 27 48.9478700(9) Stable 7/2− 0.0541(2)
50Ti 22 28 49.9447912(9) Stable 0+ 0.0518(2)
51Ti 22 29 50.946615(1) 5.76(1) min β 51V 3/2−
52Ti 22 30 51.946897(8) 1.7(1) min β 52V 0+
53Ti 22 31 52.94973(11) 32.7(9) s β 53V (3/2)−
54Ti 22 32 53.95105(13) 1.5(4) s β 54V 0+
55Ti 22 33 54.95527(16) 490(90) ms β 55V 3/2−#
56Ti 22 34 55.95820(21) 164(24) ms β (>99.9%) 56V 0+
β, n (<.1%) 55V
57Ti 22 35 56.96399(49) 60(16) ms β (>99.9%) 57V 5/2−#
β, n (<.1%) 56V
58Ti 22 36 57.96697(75)# 54(7) ms β 58V 0+
59Ti 22 37 58.97293(75)# 30(3) ms β 59V (5/2−)#
60Ti 22 38 59.97676(86)# 22(2) ms β 60V 0+
61Ti 22 39 60.98320(97)# 10# ms

[>300 ns]

β 61V 1/2−#
β, n 60V
62Ti 22 40 61.98749(97)# 10# ms 0+
63Ti 22 41 62.99442(107)# 3# ms 1/2−#

Source: Wikipedia

List of Titanium Compounds 

Titanium typically adopts the oxidation state of +4. It may also occur in the oxidation states of +3 and +2, but these are observed as less stable than the +4 oxidation state. When exposed to high temperatures, titanium reacts with other nonmetals, such as sulfur, silicon, boron, carbon, and nitrogen. This chemical element forms borides, carbides, and nitrides which are stable, hard, and possess  good refractory properties. 

 

Titanium dioxide (titanium(IV) oxide or titania) is the naturally occurring form of titanium. It can be traced in three polymorph minerals: rutile, brookite, and anatase.

Most Common Titanium Compounds

The list of most common titanium compounds includes:


  • Hexafluorotitanic acid
  • Titanium hydride
  • Niobium–titanium
  • Potassium titanyl phosphate
  • Tetrakis(dimethylamido)titanium
  • Titanic acid
  • Titanium aluminium nitride
  • Titanium bis(acetylacetonate)dichloride
  • Titanium butoxide
  • Titanium carbide
  • Titanium diboride
  • Titanium dioxide
  • Titanium dioxide nanoparticle
  • Titanium diselenide
  • Titanium disilicide
  • Titanium disulfide
  • Titanium ethoxide
  • Titanium fluoride
  • Titanium isopropoxide
  • Titanium nitrate
  • Titanium nitride
  • Titanium perchlorate
  • Titanium silicon carbide
  • Titanium tetrabromide
  • Titanium tetrachloride
  • Titanium tetrafluoride
  • Titanium tetraiodide
  • Titanium yellow
  • Titanium(II) bromide
  • Titanium(II) chloride
  • Titanium(II) iodide
  • Titanium(II) oxide
  • Titanium(II) sulfide
  • Titanium(III) bromide
  • Titanium(III) chloride
  • Titanium(III) fluoride
  • Titanium(III) iodide
  • Titanium(III) oxide
  • Titanium(III) phosphide
  • Titanium(IV) hydride
  • Titanyl
  • Titanyl sulfate

Titanates

The term ‘titanates’ refers to inorganic compounds which are made up of titanium oxides. Titanate salts create the Perovskite group together with niobate. The following is a list of the most commonly occurring titanates:


  • Barium orthotitanate
  • Barium titanate
  • Bismuth titanate
  • Caesium titanate
  • Calcium copper titanate
  • Calcium titanate
  • Dysprosium titanate
  • Europium barium titanate
  • Holmium titanate
  • Lead titanate
  • Lead zirconate titanate
  • Lithium titanate
  • Manganese(II) titanate
  • Nickel(II) titanate
  • Sodium bismuth titanate
  • Sodium metatitanate
  • Strontium titanate
  • Titanate nanosheet
  • Zinc titanate

5 Interesting Facts and Explanations

  1. Perovskite group is a class of compounds comprising calcium titanium oxide minerals. These minerals share the same crystal structure and are composed of calcium titanate (CaTiO3). 
  2. Titanocene Y (bis[(p-methoxybenzyl)cyclopentadienyl]titanium(IV) dichloride, or dichloridobis(η5-(p-methoxybenzyl)cyclopentadienyl)titanium) is an organotitanium compound actively studied as a strong cytotoxic and anti-angiogenic anticancer drug that may be effective in therapy for patients with renal-cell cancer or other solid tumors.
  3. The most important mineral sources of titanium are ilmenite (FeTiO3), rutile (TiO2), and sphene (CaTiSiO5).
  4. Titanium is the 9th most abundant element in Earth’s crust. It’s preceded only by oxygen, silicon, aluminum, iron, calcium, sodium, magnesium, and potassium.
  5. The titanium-yielding minerals rutile and ilmenite can be easily identified in beach sand.