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Química Del Rey

Química del Rey

Química del Rey is Mexican company that mines a large sodium sulfate deposit located as an underground lagoon in Laguna del Rey, Coahuila. This facility has a production capability of 600,000 (metric) tonnes of high purity sodium sulfate and 100,000 tonnes of magnesium oxide (with several grades of purity and composition). The geological origins of the deposit have been determined to be quite ancient, as evidenced by the drying up and isolation of a former sea. The origins of the company are from 1965, with the geological discovery and the commercial usage of the deposit, but is well known that the human usage of the mineralized salts of the lagoon are older, because the inhabitants from long ago separated common salt from the water through evaporation methods. The production of this facility is sold in Mexico and exported mainly to South America. The manufactured products are: Magnesium oxide ceramic grade (dead burnt) Magnesium oxide caustic grade Magnesium hydroxide in several grades Epsom salt industrial Grade Anhydrous sodium sulfate detergent Grade Anhydrous sodium sulfate textile Grade

Sodium sulfate

Sodium sulfate is an important compound of sodium. When anhydrous, it is a white crystalline solid of formula Na₂SO₄. The decahydrate, Na₂SO₄•10H₂O, is known as Glauber's salt. Sodium sulfate is mainly used for the manufacture of detergents and in the Kraft process of paper pulping, though it has many other uses. About half of the world's production is from the natural mineral form of the decahydrate (mirabilite), and half from by-products of chemical processes.

History

Glauber's salt, also sal mirabilis, is the name of sodium sulfate decahydrate, Na₂SO₄•10H₂O. It is named after Johann Glauber, who discovered it in the 17th century. The white or colorless crystals were originally used as a laxative.

Physical and chemical properties

Sodium sulfate is chemically very stable- it does not decompose, even if heated, and it does not react with oxidising or reducing agents at normal temperatures. At high temperatures, it can be reduced to sodium sulfide. It is a neutral salt, with a pH of 7 when dissolved in water, because it is derived from a strong acid (sulfuric acid) and a strong base (sodium hydroxide). In aqueous solution, some reactions are possible. Sodium sulfate reacts with an equivalent amount of sulfuric acid to give an equilibrium concentration of acid salts, such as sodium hydrogen sulfate: Na₂SO₄(aq) + H₂SO₄(aq) → 2 NaHSO₄(aq) In fact the equilibrium is very complex and dependent on concentration and temperature, with many other acid salts being present. Na₂SO₄ is a typical ionic sulfate, containing Na⁺ ions and SO₄²⁻ ions. Aqueous solutions can produce precipitates when combined with salts of barium or lead which have insoluble sulfates: Na₂SO₄(aq) + BaCl₂(aq) → 2 NaCl(aq) + BaSO₄(s) Sodium sulfate has unusual solubility characteristics in water, ³ as shown in the graph below. Its solubility rises more than tenfold between 0 °C to 32.4 °C, where it reaches a maximum of 49.7 g Na₂SO₄ per 100 g water. At this point the solubility curve suddenly changes, and the solubility becomes almost independent of temperature. If sodium chloride is added, the solubility is markedly lower. Such changes provide the basis for the use of sodium sulfate in passive solar heating systems, as well is in the preparation and purification of sodium sulfate. solar heating
This nonconformity can be explained in terms of hydration, since 32.4 °C corresponds with the temperature at which the crystalline decahydrate (Glauber's salt) changes to give a sulfate liquid phase and an anhydrous solid phase.

Occurrence

About half of the world's production of the decahydrate (Glauber's salt) is from the natural mineral form mirabilite - found in lake beds in southern Saskatchewan, for example. In 1990, Mexico and Spain were the world's main producers of natural sodium sulfate (each around 500 000 tonnes), with USSR, USA and Canada also important (around 350 000 tonnes each). Anhydrous sodium sulfate occurs in arid environments as the mineral thenardite, which is less common than mirabilite. It slowly turns to mirabilite in damp air.

Manufacture

About half of the world's sodium sulfate comes from natural sources (see above), while the other half is produced as a by-product of other processes. The most important of these is the production of hydrochloric acid from sodium chloride (salt) and sulfuric acid (the Mannheim process), in which case the Na₂SO₄ is known as salt cake: 2 NaCl + H₂SO₄ → Na₂SO₄ + 2 HCl Alternatively, it can be produced from sulfur dioxide using the Hargreaves process: 4 NaCl + 2 SO₂ + O₂ + H₂O → 2 Na₂SO₄ + 4 HCl In the US and UK, one of the largest sources of synthetic Na₂SO₄ is as a by-product of sodium dichromate manufacture. There is also a myriad of processes where leftover sulfuric acid is neutralised by sodium hydroxide, giving sodium sulfate as a by-product. This method is also the most convenient laboratory preparation. 2 NaOH(aq) + H₂SO₄(aq) → Na₂SO₄(aq) + 2 H₂O(l) Bulk sodium sulfate is usually purified via the decahydrate form, since the anhydrous form tends to attract iron compounds and organic compounds. The anhydrous form is easily produced from the hydrated form by gentle warming.

Uses

In 1995, bulk sodium sulfate sold for around $70 per tonne in the US, making it a very cheap material. Probably the largest use for sodium sulfate today is as a filler in powdered home laundry detergents. Total consumption of Na₂SO₄ in Europe was around 1.6 million tonnes in 2001, of which 80% was used for detergents. However this use is waning, as domestic consumers switch to liquid detergents which do not include sodium sulfate. Another major use for Na₂SO₄, particularly in the US, is in the Kraft process for the manufacture of wood pulp. Organics present in the "black liquor" from this process are burnt to produce heat, needed to drive the reduction of sodium sulfate to sodium sulfide. However this process is being replaced to some extent by newer processes; use of Na₂SO₄ in the US pulp industry declined from 980 000 tonnes in 1970 to only 210 000 tonnes in 1990. The glass industry also provides another significant application for sodium sulfate, consuming around 30 000 tonnes in the US in 1990 (4% of total US consumption). It is used as a "fining agent", to help remove small air bubbles from molten glass. It also fluxes the glass, and prevents scum formation of the glass melt during refining. Sodium sulfate is important in the manufacture of textiles, particularly in Japan. It helps in "levelling", reducing negative charges on fibres so that dyes can penetrate evenly. Unlike the alternative sodium chloride, it does not corrode the stainless steel vessels used in dyeing. Glauber's salt, the decahydrate, was formerly used as a laxative. It has also been proposed for heat storage in passive solar heating systems.⁶ This takes advantage of the unusual solubility properties (see above), and the high heat of crystallisation (78.2 kJ/mol). Other uses for sodium sulfate include frosting windows, in carpet fresheners, starch manufacture and as an additive to cattle feed. In the laboratory, anhydrous sodium sulfate is widely used as an inert drying agent for organic solutions; Na₂SO₄ is added to the solution until the crystals no longer clump together.

Precautions

Although sodium sulfate is generally regarded as non-toxic, handle it with care.

Suppliers/Manufacturers

Laboratory suppliers

- [https://www1.fishersci.com/index.jsp Fisher]
- [http://www.sigmaaldrich.com/ Sigma-Aldrich]
- [http://www.alfaaesar.com/ Alfa Aesar]
- [http://www.strem.com/code/index.ghc Strem]
- [http://www.vwr.com/index.htm VWR]

Manufacturers

- [http://www.elementischromium.com/products/sodiumsulphate.htm Elementis Chromium]
- [http://exporter.globalimporter.net/com/36148.htm Meishan Dongpo District Yinfeng Chemical Co.]
- [http://www.coopernatural.com/History.htm Cooper]
- [http://ludb.clui.org/ex/i/UT3171 Great LakesMinerals Co.]
- [http://www.chinatrona.com/gsjj-e.htm Chinatrona]]
- [http://www.imcchemicals.com/ IMC Chemicals]

External links

- [http://interactive.usask.ca/ski/mining/search/mineral_types/industrial/ssulphate.html "Sodium sulfate" on Saskatchewan Interactive]
- [http://www.sriconsulting.com/CEH/Public/Reports/771.1000/?Abstract.html CEH report on sodium sulfate use]
- [http://minerals.usgs.gov/minerals/pubs/commodity/sodium_sulfate/stat/ US Government statistics]
- http://www.coopernatural.com/uses.htm Uses (Cooper)]

References

# Handbook of Chemistry and Physics, 71st edition, CRC Press, Ann Arbor, Michigan, 1990. # The Merck Index, 7th edition, Merck & Co, Rahway, New Jersey, USA, 1960. # "W. F. Linke, A. Seidell, Solubilities of Inorganic and Metal Organic Compounds, 4th edition, Van Nostrand, 1965. # D. Butts, in Kirk-Othmer Encyclopedia of Chemical Technology, 4th edition, v22, p403-411 (1997). # H. Nechamkin, The Chemistry of the Elements, McGraw-Hill, New York, 1968. # Maria Telkes, Improvements in or relating to a device and a composition of matter for the storage of heat, [http://v3.espacenet.com/textdes?DB=EPODOC&IDX=GB694553&F=0&QPN=GB694553 British Patent No. GB694553] (1953). Category:Sulfates Category:Sodium compounds ja:硫酸ナトリウム

Lagoon

This article is about natural lagoons. For articial "lagoons" used to treat waste water, please see Anaerobic lagoons and Aerated lagoon. A lagoon is a body of comparatively shallow salt water separated from the deeper sea by a shallow or exposed sandbank, coral reef, or similar feature. Thus, the enclosed body of water behind a barrier reef or barrier islands or enclosed by an atoll reef is called a lagoon. This application of lagoon in English dates from 1769. It adapted and extended the sense of the Venetian laguna (cf Latin lacuna, 'empty space'), which specifically referred to Venice's shallow, island-studded stretch of salt water, protected from the Adriatic by the barrier beaches of the Lido (see Venetian Lagoon). Lagoon refers to both coastal lagoons formed by the buildup of sandbanks or reefs along shallow coastal waters, and the lagoons in atolls, formed by the grow of coral reefs on slowly sinking cental islands. Coastal lagoons are usually found on coasts with relatively small tidal ranges. They constitute approximately 13 percent of all coastlines. They generally extend parallel to the coastland, separated from the sea by barrier islands, sand and shingle bars or coral reefs. Non-reef lagoon barriers are formed by wave-action or longshore currents piling up coarser sediments off shore of the beach. Once a lagoon barrier has formed, finer sediments can settle out in the relatively quiet water behind the barrier, including sediments brought into the lagoon by rivers. Coastal lagoons typically have only constricted openings to the sea. As a result, water conditions in the lagoon can differ significantly from the open water of the sea in temperature, salinity, dissolved oxygen and sediment load. In many English-speaking countries, coastal lagoons often are called sounds, bays, rivers, or lakes. Albemarle Sound in North Carolina, Great South Bay, between Long Island and the barrier beaches of Fire Island in New York, Banana River in Florida and Lake Illawarra in New South Wales are all lagoons. In Mexico often the use of "laguna", which lagoon translates to, is used to describe a lake, such as Laguna Catemaco.
See also

- Atoll
- :Category:Atolls
- :Category:Lagoons
References

- Encyclopedia Britannica. 2005. Lagoon. Encyclopedia Britannica Premium Service. [http://www.britannica.com/eb/article-9046833] - accessed December 7, 2005.
External links

- [http://www.sms.si.edu/irlspec/Whatsa_lagoon.htm What is a lagoon?] - accessed December 7, 2005. Category:Landforms ja:ラグーン

Coahuila

Coahuila (formal name: Coahuila de Zaragoza) is one of Mexico's 31 component states. It is located in the north of the country. To the north Coahuila accounts for a 512 km stretch of the U.S.-Mexico border, adjacent to the U.S. state of Texas along the course of the Rio Grande (Río Bravo del Norte). Coahuila also borders on the Mexican states of Nuevo León to the east; San Luis Potosí and Zacatecas to the south; and Durango and Chihuahua to the west. With an area of 151,571 km², it is the nation's third biggest state. It comprises 38 municipalities (municipios). In 2000 Coahuila had an estimated population of some 2,300,000 inhabitants. The capital of Coahuila is the city of Saltillo. Coahuila also includes the cities of Monclova (a former state capital), Piedras Negras, and Torreón.

History

The Spanish explored the north of Mexico some decades after their victory in the capital of the Aztecs, because in the north climate was harsher, because there was no gold there, and because they were attacked by natives. In the 16th century, Mexico and Guatemala were included in the vice-royalty of New Spain which included Nueva Extremadura. Coahuila was part of Nueva Extremadura. Francisco Cano was one of the earliest Europeans to explore Nueva Extremadura. Coahuila y Tejas ("Coahuila and Texas") was one of the constituent states of the newly independent United Mexican States under its 1824 Constitution. Much of the territory of Texas seceded in 1836, to form the Republic of Texas. On February 19, 1856, Santiago Vidaurri annexed Coahuila to his state, Nuevo León. During the Mexican Revolution, Francisco Villa attacked the city of Torreón. On April 5, 2004, the border city of Piedras Negras was flooded. More than 30 people died and more than 4000 lost their homes.

Municipalities

Coahuila is subdivided into five regions and 38 municipalities (municipios). For a full list with municipal seats, see: municipalities of Coahuila

List of governors

This list is uncomplete
- José María Garza Galán (?-1893)
- José María Múzquiz (1894)
- Miguel Cárdenas (1894-1904)
- Jesús Valle
- Venustiano Carranza (1911-1913)
- Gustavo Espinoza Mireles (1917-1920)
- Luis Gutiérrez Ortiz (1920-1921)
- Arnulfo González (1921-1923)
- Carlos Garza Castro (1923-1925)
- Manuel Pérez Treviño (1925-1929)
- Bruno Neira González (1929-1929)
- Nazario Ortiz Garza (1929-1933)
- Jesús Valdez Sánchez (1933-1937)
- Pedro Rodríguez Triana (1937-1941)
- Gabriel Cervera Riza (1941-1941)
- Benecio López Padilla (1941-1945)
- Ignacio Cepeda Dávila (1945-1947)
- Ricardo Ainslie Rivera (1947-1948)
- Paz Faz Risa (1948-1948)
- Raúl López Sáchez (1948-1951)
- Roman Cepeda Flores (1951-1957)
- Raúl Madero González (1957-1963)
- Braulio Fernández Aguirre (1963-1969)
- Eulalio Gutiérrez Treviño (1969-1975)
- Oscar Flores Tapia (1975-1981)
- Francisco José Madero González (1981-1981)
- José de las Fuentes Rodríguez (1981-1987)
- Eliseo Mendoza Berrueto (1987-1993)
- Rogelio Montemayor Seguy (1993-1999)
- Enrique Martínez y Martínez (December 1, 1999 – )

External links

- [http://www.coahuila.gob.mx Coahuila State Government] (in Spanish)
- [http://en.coahuila.gob.mx Coahuila State Government] (in English)
- [http://cp.alternativo.net/coah.php Towns, cities, and postal codes in Coahuila] (in Spanish)
- Category:States of Mexico ja:コアウイラ州

Magnesium oxide

Magnesium oxide is a white solid mineral that occurs naturally as periclase and is a source of magnesium. See also oxide. Has an empirical formula of MgO. It is used by many libraries for preserving/deacidifying books.

Experiments Using MgO in the Classroom

Use this when discussing the differences between compounds and mixtures, and how compounds are hard to separate

Light the bunsen and put a few drops of magnesium oxide into into a test tube. Turn the bunsen to the blue flame and put the magnesium oxide under the 'triangle' (where the bunsen is the hottest). No matter how long the magnesium oxide stays under the blue flame, it will not produce a chemical change. Category:Oxides Category:Magnesium compounds

Evaporation

Evaporation is the process whereby atoms or molecules in a liquid state (or solid state if the substance sublimes) gain sufficient energy to enter the gaseous state. The thermal motion of a molecule must be sufficient to overcome the surface tension of the liquid in order for it to evaporate, that is, its kinetic energy must exceed the work function of cohesion at the surface. Evaporation therefore proceeds more quickly at higher temperature and in liquids with lower surface tension. Since only a small proportion of the molecules are located near the surface and are moving in the proper direction to escape at any given instant, the rate of evaporation is limited. Also, as the faster-moving molecules escape, the remaining molecules have lower average kinetic energy, and the temperature of the liquid thus decreases. If the evaporation takes place in a closed vessel, the escaping molecules accumulate as a vapour above the liquid. Many of the molecules return to the liquid, with returning molecules becoming more frequent as the density and pressure of the vapour increases. When the process of escape and return reaches an equilibrium, the vapour is said to be "saturated," and no further change in either vapour pressure and density or liquid temperature will occur. Gas has less order than liquid or solid matter, and thus the entropy of the system is increased, which always requires energy input. This means that the entropy change for evaporation (ΔH_evaporation) is always positive. Forced evaporation is a process used in the separation of mixtures, in which a mixture is heated to drive off the more volatile component (e.g. water), leaving behind the dry, less volatile, component. It is a misconception that at 1 atm, water vapour only exists at 100°C. Water molecules are in a constant state of evaporation and condensation flux near the surface of liquid water. If a surface molecule receives enough energy, it will leave the liquid and turn into vapour pending an allowable vapor pressure. Under a pressure of 1 atm, water will boil at 100°C.

Factors influencing rate of evaporation

- Concentration of the substance evaporating in the air. If the air already has a high concentration of the substance evaporating, then the given substance will evaporate more slowly.
- Concentration of other substances in the air. If the air is already saturated with other substances, it can have a lower capacity for the substance evaporating.
- Temperature of the substance. If the substance is hotter, then evaporation will be faster.
- Flow rate of air. This is in part related to the concentration points above. If fresh air is moving over the substance all the time, then the concentration of the substance in the air is less likely to go up with time, thus encouraging faster evaporation. In addition, molecules in motion have more energy than those at rest, and so the stronger the flow of air, the greater the evaporating power of the air molecules.
- Inter-molecular forces. The stronger the forces keeping the molecules together in the liquid or solid state the more energy that must be input in order to evaporate them.

Combustion vaporisation

The fuel droplets vapourise as they receive heat by mixing with the hot gases in the combustion chamber. Heat(energy) can also be received by radiation from any hot refractory wall of the combustion chamber.

Magnesium hydroxide

Properties
General
Name	Magnesium hydroxide
Chemical formula	Mg(OH)₂
Molar mass	58.33 g/mole
Appearance	White solid
Physical
Formula weight	58.3 u
Melting point	Decomposes at 623 K (350 °C)
Density	2.4 g/cm³
Crystal structure	?
Solubility	0.0012 g in 100 g water
Thermochemistry
Δ_fH⁰_gas	-561 kJ/mol
Δ_fH⁰_solid	-925 kJ/mol
S⁰_solid	63 J/(mol·K)
Safety
Ingestion	Safe in small amounts, but large amounts can be dangerous.
Inhalation	May cause irritation.
Skin	May cause irritation.
Eyes	May cause irritation.
More info	[http://ull.chemistry.uakron.edu/erd/chemicals/8/7704.html Hazardous Chemical Database]
SI units were used where possible. Unless otherwise stated, standard conditions were used. Disclaimer and references

Magnesium hydroxide, Mg(O H)₂, otherwise known as milk of magnesia, is commonly used as an antacid or a laxative. The mineral form of magnesium hydroxide is known as brucite. Magnesium hydroxide interferes with the absorption of folic acid and iron. The diarrhea caused by magnesium hydroxide carries away much of the body's supply of potassium, and failure to take extra potassium will lead to muscle cramps. Category:Hydroxides Category:Magnesium compounds Category:Bases ja:水酸化マグネシウム th:แมกนีเซียมไฮดรอกไซด์

This Magnesium hydroxide is a stub. You can help Wikipedia by [ expanding it].

Category:Hydroxides stubs

Magnesium sulfate

Magnesium sulfate is a chemical compound of magnesium with the formula MgSO₄. It forms a heptahydrate, MgSO₄·7H₂O, commonly called Epsom salts or bitter salts.

Origin

Epsom salt was originally prepared by boiling down mineral waters at Epsom, England and afterwards prepared from sea water. In more recent times, these salts are obtained from certain minerals such as siliceous hydrate of magnesia.

Agricultural use

In agriculture and gardening, magnesium sulfate is used to correct magnesium deficiency in soil (magnesium is an essential element in the chlorophyll molecule). It is most commonly applied to potted plants, or to magnesium hungry crops, such as potatoes, roses, and tomatoes. The advantage of magnesium sulfate over other magnesium soil amendments (such as dolomitic lime) is its high solubility.

Medical use

Main article: hypomagnesemia Locally it may be used as a treatment of an ingrown nail. Oral magnesium sulfate, or magnesium oxide, is used as a laxative. Intravenous use is broadening, as magnesium sulfate reduces striated muscle contractions and blocks peripheral neuromuscular transmission by reducing acetylcholine release at the myoneural junction, as well as other effects. Indications for its use are:
- Hypomagnesemia (low magnesium concentrations in the blood)
- In cardiac arrhythmias, most notably in:
- Atrial fibrillation
- Torsades de pointes tachycardia
- Treatment (and sometimes prevention) of seizures in eclampsia, for which it is the most effective therapy.
- As a bronchodilator after beta-agonist and anticholinergic agents have been tried, e.g. in severe exacerbations of asthma. In fact, recent studies have revealed that magnesium sulfate can be nebulized to reduce the symptoms of acute asthma (Blitz et al 2005).

Use in Organic Chemistry

Anhydrous magnsium sulfate is commonly used as a drying agent in organic synthesis due to its ability to become hydrated. During workup an organic phase is saturated with the compound until it no longer forms clumps. The hydrated solid is then removed with filtration. A number of other inorganic sulfate salts, sodium sulfate and calcium sulfate for example, may also be used in the same way.

Other uses

Magnesium sulphate is used as a bath salt, particularly in floatation therapy where high concentrations raise the bath water's specific gravity, effectively making the body more bouyant. Traditionally, it is also used to prepare foot baths, intended to soothe sore feet.

Reference

- Blitz M, Blitz S, Hughes R, Diner B, Beasley R, Knopp J, Rowe BH. Aerosolized magnesium sulfate for acute asthma: a systematic review. Chest 2005;128:337-44. PMID 16002955. Category:Magnesium compounds Category:Sulfates Category:Laxatives

Bengkulu

Bengkulu is one of the provinces of Indonesia. It is on the southwest coast of the island of Sumatra, and borders the provinces of West Sumatra, Jambi, South Sumatra and Lampung. The capital and largest city of the province is also called Bengkulu, located at . It was formerly the site of a British garrison, which they called Bencoolen. The province has a population of 1,405,060 (2000 census). The province also includes Enggano Island.

History

The British East India Company established a long-running pepper-trading center and garrison at Bengkulu (Bencoolen) in 1685. In 1714 the British built Fort Marlborough in the city; the fort still stands. The trading post was never financially profitable for the British, hampered by a location Europeans found unpleasant, and, more importantly, an inability to find sufficient pepper to buy. Despite these difficulties, the British persisted, maintaining the presence there for 150 years before ceding it to the Dutch as part of the Anglo-Dutch Treaty of 1824 to focus attention on Malacca. Like the rest of present-day Indonesia, Bengkulu remained a Dutch colony until after World War II. During Sukarno's imprisonment by the Dutch in the early 1930s, the future first president of Indonesia lived briefly in Bengkulu.

Economy

Coal mining is a major economic activity in Bengkulu. Three active coal mining companies produce between 200,000 and 400,000 tons of coal per year, which is exported to Malaysia, Singapore, South Asia, and Northeast Asia. Fishing, especially of tuna and mackerel, is an important activity. Agricultural products exported by the province include ginger, bamboo shoots, and rubber.

References

- Reid, Anthony (ed.). 1995. Witnesses to Sumatra: A traveller's anthology. Kuala Lumpur: Oxford University Press. pp. 125-133.
- Reprints of British-era primary source material
- Wilkinson, R.J. 1938. Bencoolen. Journal of the Malayan Branch Royal Asiatic Society. 16(1): 127-133.
- Overview of the British experience in Bencoolen Category:Provinces of Indonesia ms:Bengkulu nb:Bengkulu

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