Trona (trisodium hydrogendicarbonate di

hydrate In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understo ...

, also

sodium sesquicarbonate Sodium sesquicarbonate (systematic name: trisodium hydrogendicarbonate) Na3H(CO3)2 is a double salt of sodium bicarbonate and sodium carbonate (NaHCO3 · Na2CO3), and has a needle-like crystal structure. However, the term is also applied to an ...

dihydrate, Na₂CO₃•2NaHCO₃•3H₂O) is a non-

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military ...

evaporite An evaporite () is a water- soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocean ...

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...

. It is mined as the primary source of

sodium carbonate Sodium carbonate, , (also known as washing soda, soda ash and soda crystals) is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield moderately alkaline solutions ...

in the United States, where it has replaced the

Solvay process The Solvay process or ammonia-soda process is the major industrial process for the production of sodium carbonate (soda ash, Na2CO3). The ammonia-soda process was developed into its modern form by the Belgian chemist Ernest Solvay during the 1860s ...

used in most of the rest of the world for sodium carbonate production.

Etymology

The word entered English by way of either Swedish () or Spanish (), with both possible sources having the same meaning as in English. Both of these derive from the Arabic ''trōn'', which in turn derives from the Arabic ''

natron Natron is a naturally occurring mixture of sodium carbonate decahydrate ( Na2CO3·10H2O, a kind of soda ash) and around 17% sodium bicarbonate (also called baking soda, NaHCO3) along with small quantities of sodium chloride and sodium sulfate. ...

'', and Hebrew (''natruna''), which comes from

ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic pe ...

(''nitron''), derived ultimately from ancient Egyptian ''ntry'' (or ''nitry'’).

Natural deposits

Trona is found at Owens Lake and

Searles Lake Searles Lake is an endorheic dry lake in the Searles Valley of the Mojave Desert, in northwestern San Bernardino County, California. The lake in the past was also called Slate Range Lake and Borax Lake. The mining community of Trona is on i ...

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

; the

Green River Formation The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River in Colorado, Wyoming, and Utah. The sediments are deposited in very f ...

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to t ...

and

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to its ...

; the Makgadikgadi Pans in

Botswana Botswana (, ), officially the Republic of Botswana ( tn, Lefatshe la Botswana, label= Setswana, ), is a landlocked country in Southern Africa. Botswana is topographically flat, with approximately 70 percent of its territory being the Kal ...

and in the

Nile Valley The Nile, , Bohairic , lg, Kiira , Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the longest riv ...

Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a List of transcontinental countries, transcontinental country spanning the North Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via a land bridg ...

. The trona near Green River, Wyoming, is the largest known deposit in the world and lies in layered

deposits below ground, where the trona was deposited in a lake during the

Paleogene The Paleogene ( ; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago ( Mya) to the beginning o ...

Period.Wyoming Mining Association (2017)
Wyoming Mining Association: Trona Mining
Wyoming Mining Association. Retrieved on 2017-10-25. Trona has also been mined at

Lake Magadi Lake Magadi is the southernmost lake in the Kenyan Rift Valley, lying in a catchment of faulted volcanic rocks, north of Tanzania's Lake Natron. During the dry season, it is 80% covered by soda and is well known for its wading birds, including ...

in the

Kenyan Rift Valley The Great Rift Valley is part of an intra-continental ridge system that runs through Kenya from north to south. It is part of the Gregory Rift, the eastern branch of the East African Rift, which starts in Tanzania to the south and continues ...

for nearly 100 years. The northern part of

Lake Natron Lake Natron is a salt or alkaline lake located in north Ngorongoro District of Arusha Region in Tanzania. It is in the Gregory Rift, which is the eastern branch of the East African Rift. The lake is within the Lake Natron Basin, a Ramsar Si ...

is covered by a 1.5 m thick trona bed, and occurs in 'salt' pans in the

Etosha National Park Etosha National Park is a national park in northwestern Namibia and one of the largest national parks in Africa. It was proclaimed a game reserve in March 1907 in Ordinance 88 by the Governor of German South West Africa, Friedrich von Lindequist ...

Namibia Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...

. The Beypazari region in the

Ankara Province Ankara Province ( tr, , ) is a province of Turkey with the capital city Ankara. Demographics History The site of the modern city has been home to settlements by many historic Anatolian civilizations in antiquity and classical times, in ...

Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula ...

has some 33 trona beds in two fault-bound lensoid bodies in and above

oil shale Oil shale is an organic-rich fine-grained sedimentary rock containing kerogen (a solid mixture of organic chemical compounds) from which liquid hydrocarbons can be produced. In addition to kerogen, general composition of oil shales constitut ...

s of the Lower Hirka Formation (16 in the lower and 17 in the upper body). The Wucheng basin trona mine,

Henan Province Henan (; or ; ; alternatively Honan) is a landlocked province of China, in the central part of the country. Henan is often referred to as Zhongyuan or Zhongzhou (), which literally means "central plain" or "midland", although the name is al ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...

has some 36 trona beds (693–974 m deep), the lower 15 beds are 0.5–1.5 m thick, thickest 2.38 m; the upper 21 beds are 1–3 m thick, with a maximum of 4.56 m hosted and underlain by

dolomitic Dolomite () is an anhydrous carbonate mineral composed of calcium magnesium carbonate, ideally The term is also used for a sedimentary carbonate rock composed mostly of the mineral dolomite. An alternative name sometimes used for the dolomitic ...

oil shales of the Wulidui Formation. Trona has also been found in

magmatic Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...

environments.Markl, G., and Baumgartner, L. (2002) pH changes in peralkaline late-magmatic fluids. Contributions to Mineralogy and Petrology, 144, 331–346. Research has shown that trona can be formed by auto metasomatic reactions of late-magmatic fluids or melts (or

supercritical fluid A supercritical fluid (SCF) is any substance at a temperature and pressure above its critical point (chemistry), critical point, where distinct liquid and gas phases do not exist, but below the pressure required to compress it into a solid. It ca ...

-melt mixtures), with earlier crystallized rocks within the same plutonic complex, or by large-scale

vapor In physics, a vapor (American English) or vapour (British English and Canadian English; see spelling differences) is a substance in the gas phase at a temperature lower than its critical temperature,R. H. Petrucci, W. S. Harwood, and F. G. Her ...

unmixing in the very final stages of magmatism.

Crystal structure

The

crystal structure In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions or molecules in a crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric pattern ...

of trona was first determined by Brown et al. (1949). The structure consists of units of 3 edge-sharing sodium polyhedra (a central octahedron flanked by septahedra), cross-linked by carbonate groups and

hydrogen bond In chemistry, a hydrogen bond (or H-bond) is a primarily electrostatic force of attraction between a hydrogen (H) atom which is covalently bound to a more electronegative "donor" atom or group (Dn), and another electronegative atom bearing a l ...

s. Bacon and Curry (1956) refined the structure determination using two-dimensional single-crystal

neutron diffraction Neutron diffraction or elastic neutron scattering is the application of neutron scattering to the determination of the atomic and/or magnetic structure of a material. A sample to be examined is placed in a beam of thermal or cold neutrons to ob ...

, and suggested that the hydrogen atom in the symmetric (HC₂O₆)³⁻ anion is disordered. The environment of the disordered H atom was later investigated by Choi and Mighell (1982) at 300 K with three-dimensional single-crystal neutron diffraction: they concluded that the H atom is dynamically disordered between two equivalent sites, separated from one another by 0.211(9) Å. The dynamically disordered H atom was reinvestigated at low temperature by O'Bannon et al. 2014 and they concluded that it does not order at temperatures as low as 100K.

Uses of trona

* Trona is a common source of

soda ash Sodium carbonate, , (also known as washing soda, soda ash and soda crystals) is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield moderately alkaline solutions ...

, which is a significant economic commodity because of its applications in manufacturing glass, chemicals, paper, detergents, and textiles. * It is used to condition water. * It is used to remove sulfur from both

flue gas Flue gas is the gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator. Quite often, the flue gas refers to the combustion exhaust gas produc ...

es and

lignite Lignite, often referred to as brown coal, is a soft, brown, combustible, sedimentary rock formed from naturally compressed peat. It has a carbon content around 25–35%, and is considered the lowest rank of coal due to its relatively low heat ...

coals. * It is a product of

carbon sequestration Carbon sequestration is the process of storing carbon in a carbon pool. Carbon dioxide () is naturally captured from the atmosphere through biological, chemical, and physical processes. These changes can be accelerated through changes in lan ...

es. * It is also used as a food additive.

Mining operations

* Rio Tinto – Owens Lake * Magadi Soda Company * Searles Valley Minerals Inc. *

Solvay Solvay may refer to: Companies and organizations * Solvay Brussels School of Economics and Management, Brussels, Belgium * Solvay Conference, founded by Ernest Solvay, deals with open questions in physics and chemistry * Solvay Indupa, an Argentin ...

Tata Chemicals Tata Chemicals Limited is an Indian global company with interests in chemicals, crop protection and specialty chemistry products headquartered in Mumbai, India. The company is one of the largest chemical companies in India with operations in ...

* Genesis Alkali formerly

Tronox Tronox Limited is an American worldwide chemical company involved in the titanium products industry with approximately 6,500 employees. Following its acquisition of the mineral sands business formerly belonging to South Africa's Exxaro Resources ...

Alkali ''formerly

FMC Corporation FMC Corporation is an American chemical manufacturing company headquartered in Philadelphia, Pennsylvania, which originated as an insecticide producer in 1883 and later diversified into other industries. In 1941 at the beginning of US involvemen ...

'' * General Chemical * Ciner Wyoming ''formerly OCI Chemical Corp.'' * ANSAC *

Eti Soda The Eti Soda Inc. is a chemical industry company in Ankara Province, Turkey producing natural soda ash and baking soda from trona. It was founded in 1998, and the production started in 2009. The company's main shareholder is Ciner Group. Backgro ...

, Turkey * Kazan Soda Elektrik, Turkey * Church & Dwight - Green River Mine * Intrepid Potash *

Simplot The J. R. Simplot Company (commonly referred to as Simplot) is an agribusiness company headquartered in Boise, Idaho. History Simplot was founded in 1929 by 20-year-old John Richard Simplot near the agricultural community of Declo in south ...

References