Misplaced Pages

Worsley Alumina

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.

Sodium hydroxide , also known as lye and caustic soda , is an inorganic compound with the formula NaOH . It is a white solid ionic compound consisting of sodium cations Na and hydroxide anions OH .

#871128

63-413: Worsley Alumina comprises a bauxite mine located near the town of Boddington and an Alumina refinery located near Worsley . Ore is mined then transported 50 km (31 mi) to the refinery via an overland conveyor system. Alumina is then transported 55 km (34 mi) to the port of Bunbury for shipping. The Boddington Bauxite Mine is located south of the town of Boddington, and comprises

126-447: A drain cleaner . Worldwide production in 2022 was approximately 83 million tons. Pure sodium hydroxide is a colorless crystalline solid that melts at 318 °C (604 °F) without decomposition and boils at 1,388 °C (2,530 °F). It is highly soluble in water, with a lower solubility in polar solvents such as ethanol and methanol . Sodium hydroxide is insoluble in ether and other non-polar solvents. Similar to

189-556: A primary standard because it is hygroscopic and absorbs carbon dioxide from air. Sodium hydroxide also reacts with acidic oxides , such as sulfur dioxide . Such reactions are often used to " scrub " harmful acidic gases (like SO 2 and H 2 S ) produced in the burning of coal and thus prevent their release into the atmosphere. For example, Glass reacts slowly with aqueous sodium hydroxide solutions at ambient temperatures to form soluble silicates . Because of this, glass joints and stopcocks exposed to sodium hydroxide have

252-496: A sodium hydroxide solution at a temperature of 150 to 200 °C (300 to 390 °F). At these temperatures, the aluminium is dissolved as sodium aluminate (the Bayer process ). The aluminium compounds in the bauxite may be present as gibbsite (Al(OH) 3 ), boehmite (AlOOH) or diaspore (AlOOH); the different forms of the aluminium component will dictate the extraction conditions. The undissolved waste, bauxite tailings , after

315-524: A characteristic viscosity , 78 m Pa ·s, that is much greater than that of water (1.0 mPa·s) and near that of olive oil (85 mPa·s) at room temperature. The viscosity of aqueous NaOH , as with any liquid chemical, is inversely related to its temperature, i.e., its viscosity decreases as temperature increases, and vice versa. The viscosity of sodium hydroxide solutions plays a direct role in its application as well as its storage. Sodium hydroxide can form several hydrates NaOH· n H 2 O , which result in

378-458: A clear solution of Na 2 ZnO 2 or Na 2 PbO 2 . Aluminium hydroxide is used as a gelatinous flocculant to filter out particulate matter in water treatment . Aluminium hydroxide is prepared at the treatment plant from aluminium sulfate by reacting it with sodium hydroxide or bicarbonate. Sodium hydroxide can be used for the base-driven hydrolysis of esters (also called saponification ), amides and alkyl halides . However,

441-540: A complex solubility diagram that was described in detail by Spencer Umfreville Pickering in 1893. The known hydrates and the approximate ranges of temperature and concentration (mass percent of NaOH) of their saturated water solutions are: Early reports refer to hydrates with n = 0.5 or n = 2/3, but later careful investigations failed to confirm their existence. The only hydrates with stable melting points are NaOH·H 2 O (65.10 °C) and NaOH·3.5H 2 O (15.38 °C). The other hydrates, except

504-542: A four-stage Bayer Process to transform the red bauxite rock into white alumina powder. It is powered by coal, producing 3.7 million tonnes (8.2 billion pounds) of carbon per year averaged for 2017–2021, making it the fourth-biggest carbon polluter in Western Australia. The carbon intensity of Worsley Alumina is 820 kilograms per tonne (13.1 ounces per pound) of CO 2 per alumina produced. Bauxite Bauxite ( / ˈ b ɔː k s aɪ t / )

567-431: A liquid solution. Even the n = 3.5 hydrate is difficult to crystallize, because the solution supercools so much that other hydrates become more stable. A hot water solution containing 73.1% (mass) of NaOH is a eutectic that solidifies at about 62.63 °C as an intimate mix of anhydrous and monohydrate crystals. A second stable eutectic composition is 45.4% (mass) of NaOH, that solidifies at about 4.9 °C into

630-407: A liquid with 35.7% NaOH and density 1.392 g/cm , and therefore floats on it like ice on water. However, at about 4.9 °C it may instead melt incongruously into a mixture of solid NaOH·3.5H 2 O and a liquid solution. The β form of the tetrahydrate is metastable, and often transforms spontaneously to the α form when cooled below −20 °C. Once initiated, the exothermic transformation

693-749: A man who worked for drug cartels admitted disposing of over 300 bodies with it. Sodium hydroxide is a dangerous chemical due to its ability to hydrolyze protein. If a dilute solution is spilled on the skin, burns may result if the area is not washed thoroughly and for several minutes with running water. Splashes in the eye can be more serious and can lead to blindness. Strong bases attack aluminium . Sodium hydroxide reacts with aluminium and water to release hydrogen gas. The aluminium takes an oxygen atom from sodium hydroxide, which in turn takes an oxygen atom from water, and releases two hydrogen atoms. The reaction thus produces hydrogen gas and sodium aluminate . In this reaction, sodium hydroxide acts as an agent to make

SECTION 10

#1732790390872

756-495: A mixture of crystals of the dihydrate and of the 3.5-hydrate. The third stable eutectic has 18.4% (mass) of NaOH. It solidifies at about −28.7 °C as a mixture of water ice and the heptahydrate NaOH·7H 2 O . When solutions with less than 18.4% NaOH are cooled, water ice crystallizes first, leaving the NaOH in solution. The α form of the tetrahydrate has density 1.33 g/cm . It melts congruously at 7.55 °C into

819-450: A moist slurry forms in the can, then there is a likelihood for the cargo to liquefy; although conversely, even if the sample remains dry it does not conclusively prove that it will remain that way, or that it is safe for loading. Bauxite is the main source of the rare metal gallium . During the processing of bauxite to alumina in the Bayer process , gallium accumulates in the sodium hydroxide liquor. From this it can be extracted by

882-461: A petition against the mining of bauxite that was signed by 135 accomplished and well known "Intellectuals". This petition helped unite the scattered anti-bauxite movement into a unified opposition against the state. These acts of governmental defiance were met with repressive state actions. Many domestic online reporters were arrested, and legislative action was taken to repress scientific research. Most of India's bauxite ore reserves, which are among

945-458: A temperature in excess of 1,000 °C (1,830 °F). This aluminium oxide is dissolved at a temperature of about 960 °C (1,760 °F) in molten cryolite . Next, this molten substance can yield metallic aluminium by passing an electric current through it in the process of electrolysis, which is called the Hall–Héroult process , named after its American and French discoverers. Prior to

1008-491: A tendency to "freeze". Flasks and glass-lined chemical reactors are damaged by long exposure to hot sodium hydroxide, which also frosts the glass. Sodium hydroxide does not attack iron at room temperature, since iron does not have amphoteric properties (i.e., it only dissolves in acid, not base). Nevertheless, at high temperatures (e.g. above 500 °C), iron can react endothermically with sodium hydroxide to form iron(III) oxide , sodium metal, and hydrogen gas. This

1071-499: A variety of methods. The most recent is the use of ion-exchange resin . Achievable extraction efficiencies critically depend on the original concentration in the feed bauxite. At a typical feed concentration of 50 ppm, about 15 percent of the contained gallium is extractable. The remainder reports to the red mud and aluminium hydroxide streams. Bauxite is also a potential source for vanadium . The social and environmental impacts of bauxite extraction are well documented. Most of

1134-665: A youth march. In 2020, A Rocha Ghana also sued the government over the drilling in the reserve after they failed to provide a statement explaining their actions. In early 2009, the Vietnamese Government proposed a plan to mine remote regions of the central highlands. This proposal was highly controversial and sparked a nationwide debate and the most significant domestic conflict since the Vietnam War . Government scientists, journalists, religious leaders, retired high level state officials, and General Võ Nguyên Giáp ,

1197-572: Is a sedimentary rock with a relatively high aluminium content. It is the world's main source of aluminium and gallium . Bauxite consists mostly of the aluminium minerals gibbsite ( Al(OH) 3 ), boehmite (γ-AlO(OH)) and diaspore (α-AlO(OH)), mixed with the two iron oxides goethite (FeO(OH)) and haematite ( Fe 2 O 3 ), the aluminium clay mineral kaolinite ( Al 2 Si 2 O 5 (OH) 4 ) and small amounts of anatase ( TiO 2 ) and ilmenite ( FeTiO 3 or FeO·TiO 2 ). Bauxite appears dull in luster and

1260-429: Is complete in a few minutes, with a 6.5% increase in volume of the solid. The β form can be crystallized from supercooled solutions at −26 °C, and melts partially at −1.83 °C. The "sodium hydroxide" of commerce is often the monohydrate (density 1.829 g/cm ). Physical data in technical literature may refer to this form, rather than the anhydrous compound. NaOH and its monohydrate form orthorhombic crystals with

1323-416: Is cooled, the monohydrate normally starts to crystallize (at about 22 °C) before the dihydrate. However, the solution can easily be supercooled down to −15 °C, at which point it may quickly crystallize as the dihydrate. When heated, the solid dihydrate might melt directly into a solution at 13.35 °C; however, once the temperature exceeds 12.58 °C it often decomposes into solid monohydrate and

SECTION 20

#1732790390872

1386-562: Is due to the lower enthalpy of formation of iron(III) oxide (−824.2 kJ/mol) compared to sodium hydroxide (−500 kJ/mol) and positive entropy change of the reaction, which implies spontaneity at high temperatures ( ΔST > ΔH , ΔG < 0 ) and non-spontaneity at low temperatures ( ΔST < ΔH , ΔG > 0 ). Consider the following reaction between molten sodium hydroxide and finely divided iron filings: A few transition metals , however, may react quite vigorously with sodium hydroxide under milder conditions. In 1986, an aluminium road tanker in

1449-466: Is formed is toxic and difficult to deal with, and the process is banned in many countries because of this. In 2006, Trafigura used the process and then dumped the waste in Ivory Coast . Other common uses of sodium hydroxide include: Sodium hydroxide is also widely used in pulping of wood for making paper or regenerated fibers. Along with sodium sulfide , sodium hydroxide is a key component of

1512-448: Is given by: This reaction can be useful in etching , removing anodizing, or converting a polished surface to a satin-like finish, but without further passivation such as anodizing or alodining the surface may become degraded, either under normal use or in severe atmospheric conditions. In the Bayer process , sodium hydroxide is used in the refining of alumina containing ores ( bauxite ) to produce alumina ( aluminium oxide ) which

1575-462: Is industrially produced, first as a 32% solution, and then evaporated to a 50% solution by variations of the electrolytic chloralkali process . Chlorine gas is also produced in this process. Solid sodium hydroxide is obtained from this solution by the evaporation of water. Solid sodium hydroxide is most commonly sold as flakes, prills , and cast blocks. In 2022, world production was estimated at 83 million dry tonnes of sodium hydroxide, and demand

1638-432: Is often this monohydrate, and published data may refer to it instead of the anhydrous compound. As one of the simplest hydroxides, sodium hydroxide is frequently used alongside neutral water and acidic hydrochloric acid to demonstrate the pH scale to chemistry students. Sodium hydroxide is used in many industries: in the making of wood pulp and paper , textiles , drinking water , soaps and detergents , and as

1701-453: Is one of the only two upland evergreen forests in Ghana, and makes up a significant portion of the remaining 20% of forested habitat left in Ghana. The Atewa range falls under the jurisdiction of Akyem Abuakwa Traditional Area and is overseen by the king known as Okyenhene. In 2013, an NGO called A Rocha Ghana held a summit with the forestry and water resource commission, the minister of lands,

1764-515: Is reddish-brown, white, or tan. In 1821, the French geologist Pierre Berthier discovered bauxite near the village of Les Baux in Provence , southern France . Numerous classification schemes have been proposed for bauxite but, as of 1982 , there was no consensus. Vadász (1951) distinguished lateritic bauxites (silicate bauxites) from karst bauxite ores (carbonate bauxites): In

1827-465: Is the raw material used to produce aluminium via the electrolytic Hall-Héroult process . Since the alumina is amphoteric , it dissolves in the sodium hydroxide, leaving impurities less soluble at high pH such as iron oxides behind in the form of a highly alkaline red mud . Other amphoteric metals are zinc and lead which dissolve in concentrated sodium hydroxide solutions to give sodium zincate and sodium plumbate respectively. Sodium hydroxide

1890-409: Is used in many scenarios where it is desirable to increase the alkalinity of a mixture, or to neutralize acids. For example, in the petroleum industry, sodium hydroxide is used as an additive in drilling mud to increase alkalinity in bentonite mud systems, to increase the mud viscosity , and to neutralize any acid gas (such as hydrogen sulfide and carbon dioxide ) which may be encountered in

1953-534: The Boké Region of Guinea have caused in 35 conflicts which include movements of revolts and road blockades. These conflicts have resulted in the loss of human life, the destruction of heavy machinery, and damage to government buildings. The Atewa range in Ghana, classified as an ecologically important forest reserve with an area of 17,400 hectares (43,000 acres), has been is a recent site of conflict and controversy surrounding baxuite mining. The forest reserve

Worsley Alumina - Misplaced Pages Continue

2016-582: The Boké Region of Guinea, there has been a significant increase in bauxite mining pressure on the local population. This has resulted in potable water issues, air pollution, food contamination, and land expropriation disputes due to improper compensation. Bauxite mining has led to protests, civil unrest, and violent conflicts in Guinea, Ghana, Vietnam, and India. Guinea has a long history of mining related conflicts between communities and mining companies. Between 2015 and 2018, new bauxite mining operations in

2079-520: The Ghana Integrated Bauxite and Aluminium Development Authority Act that would create the legal framework required to develop and establish an integrated bauxite industry. In may of that year, the government began drilling deep holes in the reserve. These actions sparked several protests, including a 95-kilometre (59 mi) march from the reserve to the presidential palace, an informational billboard campaign led by A Rocha Ghana, and

2142-595: The Rayagada district of Odisha . Sodium hydroxide Sodium hydroxide is a highly corrosive base and alkali that decomposes lipids and proteins at ambient temperatures and may cause severe chemical burns . It is highly soluble in water , and readily absorbs moisture and carbon dioxide from the air . It forms a series of hydrates NaOH· n H 2 O . The monohydrate NaOH·H 2 O crystallizes from water solutions between 12.3 and 61.8 °C. The commercially available "sodium hydroxide"

2205-460: The Solvay process in the late 19th century. The conversion of sodium carbonate to sodium hydroxide was superseded entirely by the chloralkali process , which produces sodium hydroxide in a single process. Sodium hydroxide is also produced by combining pure sodium metal with water. The byproducts are hydrogen gas and heat, often resulting in a flame. This reaction is commonly used for demonstrating

2268-472: The chloralkali process . Historically, sodium hydroxide was produced by treating sodium carbonate with calcium hydroxide (slaked lime) in a metathesis reaction which takes advantage of the fact that sodium hydroxide is soluble, while calcium carbonate is not. This process was called causticizing. The sodium carbonate for this reaction was produced by the Leblanc process in the early 19th century, or

2331-463: The free surface effect can cause the cargo to shift rapidly inside the hold and make the ship unstable, potentially sinking the ship. One vessel suspected to have been sunk in this way was the MS Bulk Jupiter in 2015. One method which can demonstrate this effect is the "can test", in which a sample of the material is placed in a cylindrical can and struck against a surface many times. If

2394-578: The geological formation as drilling progresses. Another use is in salt spray testing where pH needs to be regulated. Sodium hydroxide is used with hydrochloric acid to balance pH. The resultant salt, NaCl, is the corrosive agent used in the standard neutral pH salt spray test. Poor quality crude oil can be treated with sodium hydroxide to remove sulfurous impurities in a process known as caustic washing . Sodium hydroxide reacts with weak acids such as hydrogen sulfide and mercaptans to yield non-volatile sodium salts, which can be removed. The waste which

2457-593: The UK was mistakenly used to transport 25% sodium hydroxide solution, causing pressurization of the contents and damage to tankers. The pressurization is due to the hydrogen gas which is produced in the reaction between sodium hydroxide and aluminium: Unlike sodium hydroxide, which is soluble, the hydroxides of most transition metals are insoluble, and therefore sodium hydroxide can be used to precipitate transition metal hydroxides. The following colours are observed: Zinc and lead salts dissolve in excess sodium hydroxide to give

2520-410: The aluminium compounds are extracted contains iron oxides , silica , calcia , titania and some un-reacted alumina . After separation of the residue by filtering, pure gibbsite is precipitated when the liquid is cooled, and then seeded with fine-grained aluminium hydroxide . The gibbsite is usually converted into aluminium oxide , Al 2 O 3 , by heating in rotary kilns or fluid flash calciners to

2583-638: The case of Jamaica , recent analysis of the soils showed elevated levels of cadmium , suggesting that the bauxite originates from Miocene volcanic ash deposits from episodes of significant volcanism in Central America. Australia is the largest producer of bauxite, followed by Guinea and China . Bauxite is usually strip mined because it is almost always found near the surface of the terrain , with little or no overburden . Increased aluminium recycling , which requires less electric power than producing aluminium from ores, may considerably extend

Worsley Alumina - Misplaced Pages Continue

2646-405: The corresponding salts. For example, when sodium hydroxide reacts with hydrochloric acid , sodium chloride is formed: In general, such neutralization reactions are represented by one simple net ionic equation: This type of reaction with a strong acid releases heat, and hence is exothermic . Such acid–base reactions can also be used for titrations . However, sodium hydroxide is not used as

2709-404: The end of the stages. In a similar fashion, sodium hydroxide is used to digest tissues, as in a process that was used with farm animals at one time. This process involved placing a carcass into a sealed chamber, then adding a mixture of sodium hydroxide and water (which breaks the chemical bonds that keep the flesh intact). This eventually turns the body into a liquid with a dark brown color, and

2772-505: The hydration of sulfuric acid, dissolution of solid sodium hydroxide in water is a highly exothermic reaction where a large amount of heat is liberated, posing a threat to safety through the possibility of splashing. The resulting solution is usually colorless and odorless. As with other alkaline solutions, it feels slippery with skin contact due to the process of saponification that occurs between NaOH and natural skin oils. Concentrated (50%) aqueous solutions of sodium hydroxide have

2835-488: The invention of this process, and prior to the Deville process , aluminium ore was refined by heating ore along with elemental sodium or potassium in a vacuum . The method was complicated and consumed materials that were themselves expensive at that time. This made early elemental aluminium more expensive than gold . As a bulk cargo , bauxite is a Group A cargo that may liquefy if excessively moist. Liquefaction and

2898-535: The limited solubility of sodium hydroxide in organic solvents means that the more soluble potassium hydroxide (KOH) is often preferred. Touching a sodium hydroxide solution with bare hands, while not recommended, produces a slippery feeling. This happens because oils on the skin such as sebum are converted to soap. Despite solubility in propylene glycol it is unlikely to replace water in saponification due to propylene glycol's primary reaction with fat before reaction between sodium hydroxide and fat. Sodium hydroxide

2961-431: The metastable ones NaOH·3H 2 O and NaOH·4H 2 O (β) can be crystallized from solutions of the proper composition, as listed above. However, solutions of NaOH can be easily supercooled by many degrees, which allows the formation of hydrates (including the metastable ones) from solutions with different concentrations. For example, when a solution of NaOH and water with 1:2 mole ratio (52.6% NaOH by mass)

3024-462: The military leader of anti-colonial revolution, were among the many people across Vietnamese society who opposed the governments plans. In an attempt to stop the spread of information across the globe, the government banned domestic reporters from reporting on bauxite mining. However, reporters turned to Vietnamese language websites and blogs where the reporting and discussion continued. On April 12, 2009, several well-respected Vietnamese scholars started

3087-401: The minister of the environment, and other important stakeholders. They came to the conclusion that no future government should mine bauxite in the region because the reserve is environmentally and culturally significant. In 2016, the government along with NGO's began the process of upgrading the reserved to a national park. However, that year an election took place, and before it became official,

3150-492: The newly elected National Patriotic Party (NPP) rejected the plan. In 2017, the government of Ghana signed a Memorandum of Understanding with China to develop new bauxite mining infrastructure in Ghana. Although there was no official plan to mine the Atewa Forest Reserve, tensions between local communities, NGO and the government began to rise. In 2019, tensions began to reach a peak when the government presented

3213-422: The only solids that remain are bone hulls, which can be crushed between one's fingertips. Sodium hydroxide is frequently used in the process of decomposing roadkill dumped in landfills by animal disposal contractors. Due to its availability and low cost, it has been used by criminals to dispose of corpses. Italian serial killer Leonarda Cianciulli used this chemical to turn dead bodies into soap. In Mexico,

SECTION 50

#1732790390872

3276-516: The reactivity of alkali metals in academic environments; however, it is not used commercially aside from a reaction within the mercury cell chloralkali process where sodium amalgam is reacted with water. Sodium hydroxide is a popular strong base used in industry. Sodium hydroxide is used in the manufacture of sodium salts and detergents, pH regulation, and organic synthesis. In bulk, it is most often handled as an aqueous solution , since solutions are cheaper and easier to handle. Sodium hydroxide

3339-506: The solution alkaline, which aluminium can dissolve in. Sodium aluminate is an inorganic chemical that is used as an effective source of aluminium hydroxide for many industrial and technical applications. Pure sodium aluminate (anhydrous) is a white crystalline solid having a formula variously given as NaAlO 2 , Na 3 AlO 3 , Na[Al(OH) 4 ] , Na 2 O·Al 2 O 3 or Na 2 Al 2 O 4 . Formation of sodium tetrahydroxoaluminate(III) or hydrated sodium aluminate

3402-560: The space groups Cmcm ( oS8 ) and Pbca (oP24), respectively. The monohydrate cell dimensions are a = 1.1825, b = 0.6213, c = 0.6069 nm . The atoms are arranged in a hydrargillite -like layer structure, with each sodium atom surrounded by six oxygen atoms, three each from hydroxide ions and three from water molecules. The hydrogen atoms of the hydroxyls form strong bonds with oxygen atoms within each O layer. Adjacent O layers are held together by hydrogen bonds between water molecules. Sodium hydroxide reacts with protic acids to produce water and

3465-706: The strip mining process, the biodiversity and habitat once present in the area is completely lost and the hydrological and soil characteristics in the region are permanently altered. Other environmental impacts of bauxite mining include soil degradation , air pollution , and water pollution . Red mud is a highly alkaline sludge, with a high pH around 13, that is a byproduct of the Bayer process .  It contains several elements such as sodium aluminoscilicate , calcium titanate , monohydrate aluminium, and trihydrate aluminium that do not break down in nature. When improperly stored, red mud can contaminate soil and water, which can result in local extinction of all life. Red mud

3528-466: The terrestrial and aquatic ecosystems. Historically, the Indigenous peoples living on these lands have shown resistance to development, and oppose any new bauxite mining projects in the area. This has led to violent conflicts between Indigenous communities and police. On December 16, 2000, police killed three Indigenous protestors and wounded over a dozen more during a protest over a bauxite project in

3591-401: The top ten largest in the world, are located on tribal land. These tribal lands are densely populated and home to over 100 million Indigenous Indian peoples.  The mountain summits located on these lands act as a source of water and greatly contribute to the regions fertility. The Indian bauxite industry is interested in developing this land for aluminum production, which poses great risk to

3654-539: The two sites of Saddleback and Marradong . The orebody exists as a hardcap layer of between 2–12 metres (6 ft 7 in – 39 ft 4 in) thick, it is drilled and blasted before bulldozers can access the softer ore below. The ore is first crushed to a diameter less than 18 cm (7.1 in) before a second stage reduces it to 3 cm (1.2 in). In the current approved Life of Operation Plan, total ore reserves are scheduled to be depleted by 30 June 2035. The refinery, also owned by South32 , uses

3717-399: The white liquor solution used to separate lignin from cellulose fibers in the kraft process . It also plays a key role in several later stages of the process of bleaching the brown pulp resulting from the pulping process. These stages include oxygen delignification, oxidative extraction, and simple extraction, all of which require a strong alkaline environment with a pH > 10.5 at

3780-436: The world's bauxite deposits can be found within 1 to 20 metres (3 ft 3 in to 65 ft 7 in) of the earths surface. Strip mining is the most common technique used for extracting shallow bauxite. This process involves removing the vegetation, top soil, and overburden to expose the bauxite ore. The overlying soil is typically stockpiled in order to rehabilitate the mine once operations have finished. During

3843-401: The world's bauxite reserves. As of 2010 , approximately 70% to 80% of the world's dry bauxite production is processed first into alumina and then into aluminium by electrolysis . Bauxite rocks are typically classified according to their intended commercial application: metallurgical, abrasive, cement, chemical, and refractory. Bauxite ore is usually heated in a pressure vessel along with

SECTION 60

#1732790390872

3906-719: Was estimated at 51 million tonnes. In 1998, total world production was around 45 million tonnes . North America and Asia each contributed around 14 million tonnes, while Europe produced around 10 million tonnes. In the United States, the major producer of sodium hydroxide is Olin , which has annual production around 5.7 million tonnes from sites at Freeport, Texas ; Plaquemine, Louisiana ; St. Gabriel, Louisiana ; McIntosh, Alabama ; Charleston, Tennessee ; Niagara Falls, New York ; and Bécancour, Canada . Other major US producers include Oxychem , Westlake , Shintek, and Formosa . All of these companies use

3969-575: Was responsible for killing all life in the Marcal River in Hungary after a spill occurred in 2010. When red mud dries, it turns into dust that can cause lung disease, cancer and birth defects. In the tropical regions of Asia, central Africa, South America and northern Australia, there has been an increase of bauxite mines on traditional and indigenous lands. This has resulted in a number of negative social impacts on local and indigenous peoples. In

#871128