Hunter process
Encyclopedia
The Hunter process was the first industrial process to produce pure ductile metallic titanium
. It was invented in 1910 by Matthew A. Hunter, a chemist
born in New Zealand, who worked in America.
The process begins by preparing a mixture of rutile
(a mineral consisting of titanium dioxide
, TiO2) with chlorine
(Cl2) and coke
. The coke serves as a source of carbon which reacts with the oxygen
(O2) in the TiO2 when extreme heat is applied, producing titanium tetrachloride
(TiCl4) and carbon dioxide
(CO2).
The titanium tetrachloride is reduced with sodium
(Na) to form pure metallic titanium (99.9%) by heating TiCl4 with Na in a steel bomb at 700–800 °C. This final step is the actual Hunter process. It successfully produces very high quality titanium, but it was replaced in all but the most demanding applications by the more economical Kroll process
in the 1940s.
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color....
. It was invented in 1910 by Matthew A. Hunter, a chemist
Chemist
A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties such as density and acidity. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms...
born in New Zealand, who worked in America.
The process begins by preparing a mixture of rutile
Rutile
Rutile is a mineral composed primarily of titanium dioxide, TiO2.Rutile is the most common natural form of TiO2. Two rarer polymorphs of TiO2 are known:...
(a mineral consisting of titanium dioxide
Titanium dioxide
Titanium dioxide, also known as titanium oxide or titania, is the naturally occurring oxide of titanium, chemical formula . When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891. Generally it comes in two different forms, rutile and anatase. It has a wide range of...
, TiO2) with chlorine
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
(Cl2) and coke
Coke (fuel)
Coke is the solid carbonaceous material derived from destructive distillation of low-ash, low-sulfur bituminous coal. Cokes from coal are grey, hard, and porous. While coke can be formed naturally, the commonly used form is man-made.- History :...
. The coke serves as a source of carbon which reacts with the oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
(O2) in the TiO2 when extreme heat is applied, producing titanium tetrachloride
Titanium tetrachloride
Titanium tetrachloride is the inorganic compound with the formula TiCl4. It is an important intermediate in the production of titanium metal and the pigment titanium dioxide. TiCl4 is an unusual example of a metal halide that is highly volatile...
(TiCl4) and carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
(CO2).
The titanium tetrachloride is reduced with sodium
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
(Na) to form pure metallic titanium (99.9%) by heating TiCl4 with Na in a steel bomb at 700–800 °C. This final step is the actual Hunter process. It successfully produces very high quality titanium, but it was replaced in all but the most demanding applications by the more economical Kroll process
Kroll process
Kroll Process is a pyrometallurgical industrial process used to produce metallic titanium. It was invented by William J. Kroll in Luxembourg. After moving to the United States, Kroll further developed the method for the production of zirconium...
in the 1940s.
- TiO2Titanium dioxideTitanium dioxide, also known as titanium oxide or titania, is the naturally occurring oxide of titanium, chemical formula . When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891. Generally it comes in two different forms, rutile and anatase. It has a wide range of...
(s) + 2Cl2ChlorineChlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
(g) + CCarbonCarbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
(s) → TiCl4Titanium tetrachlorideTitanium tetrachloride is the inorganic compound with the formula TiCl4. It is an important intermediate in the production of titanium metal and the pigment titanium dioxide. TiCl4 is an unusual example of a metal halide that is highly volatile...
(l) + CO2Carbon dioxideCarbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
(g)
- TiCl4Titanium tetrachlorideTitanium tetrachloride is the inorganic compound with the formula TiCl4. It is an important intermediate in the production of titanium metal and the pigment titanium dioxide. TiCl4 is an unusual example of a metal halide that is highly volatile...
(l) + 4NaSodiumSodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
(l) → 4NaClSodium chlorideSodium chloride, also known as salt, common salt, table salt or halite, is an inorganic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...
(l) + TiTitaniumTitanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color....
(s)