The aluminium compound in bauxite is aluminium oxide and the main impurity is iron (III) oxide, Aluminium is obtained by the electrolysis of aluminium oxide dissolved in cryolite (i) Name the process used for the purification of bauxite (ii) Write the equation for the action of heat on aluminium hydroxide
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Serpeck's process is used for the purification of white bauxite which does not contain F e2O3 as an impurify. Name the process used for purification of white bauxite ore containing no iron oxide as impurity (A) Baeyer's process (B) Hall's process (C) Serpe.
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One of the major constituents in the bauxite residue is iron oxide as Fe 2 O 3 (3555% depending on the bauxite characteristics) and can be recovered after employing suitable physical separation processes. Increase in iron oxide content in red mud will enhance its utilization in the extraction of iron metal. These separation methods if ...
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Serpeck's process. This process is used for the purification of bauxite ore containing silica (SiO 2) as the main impurity. The powdered ore is mixed with coke and the mixture is heated at about 1800°C in the presence of Nitrogen gas, when aluminium nitride is formed. Al 2 O 3. 2H 2 O + 3C + N 2 → 2AI N + 3CO+ 2H 2 O
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Solution Bayer's process is used for the purification of bauxite Al 2 O 3 · 2 H 2 O. Aluminium is extracted by Bayer's process. The bauxite is powdered and mixed with a concentrated solution of caustic soda NaOH to give sodium meta aluminate and impurities are removed by filtration.
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Serpeck's process is the process of converting bauxite into aluminum nitride. This process is generally used when silica is present in the bauxite ore. Therefore, Hall's process, Baeyer's process and Serpeck's process are the various processes used for the purification of bauxite. Hence, options A,B and C are correct. Separation ...
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Bauxite(A l 2 O 3 . H 2 O) is an important ore of aluminium with large impurities and is hence first roasted and then treated with concentrated solution of caustic soda. This dissolves aluminium oxide present in bauxite due to the formation of sodium aluminate, (N a A l O 2 ). A l 2 O 2 . H 2 O + 2 N a O H → 2 N a A l O 2 + 3 H 2 O.
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As the minerals are weathered they gradually breakdown into various forms of hydrated aluminum oxide, Al 2 O 3 .xH 2 O, known as bauxite. The bauxite is purified by the Bayer Process. First the ore is mixed with a hot concentrated solution of sodium hydroxide. The NaOH will dissolve the oxides of aluminum and silicon but not other impurities ...
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The process dissolves the aluminium component of bauxite ore in sodium hydroxide (caustic soda). Under pressure of 3500 kPa and high tem peratures the chemical reactions are rapid [6] : Gibbsite
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A process for producing alumina from bauxite is described in which bauxite is treated with an alkali to form a mixture comprising a solution of aluminumcontaining ions and alumina trihydrate is precipitated from the solution. The process comprises treatment of the solution before or after the precipitation step with a layered double hydroxide in order to remove impurities from the solution by ...
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The ore is first converted into pure aluminium oxide by the Bayer Process, and this is then electrolysed in solution in molten cryolite another aluminium compound. The aluminium oxide has too high a melting point to electrolyse on its own. Aluminium ore. The usual aluminium ore is bauxite. Bauxite is essentially an impure aluminium oxide.
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Armand Dufrénoy names the ore "beauxite" 1861: Henri SainteClaire Deville renames it as "bauxite" 1854: SainteClaire Deville discovers a method to separate kilogram amounts of aluminium from its oxide, alumina: 1886: Charles Martin Hall and Paul Héroult independently develop a process for making aluminium from alumina: 1887
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(i) State the reason for addition of caustic alkali to bauxite ore during purification of bauxite. (ii) Give a balanced chemical equation for the above reaction. (iii) Along with cryolite and alumina, another substance is added to the electrolyte mixture. Name the substance and give one reason for the addition. [3]
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Red mud is a slimy caustic residue generated from alumina refining of bauxite ores. During the alumina extraction process, about 35 %40 % of the bauxite ores go into the residue as highly alkaline red mud slurry (pH ) which contains 15 %40 % of solid phase in volume [1, 2].Depending on the quality of bauxite ores, producing 1 t alumina basically generates t red mud [].
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Generally, froth flotation as an enhanced, less costly environmental achievable physical separation method has been employed to increase the mass ratio of Al/Si for adequate purification and pretreatment of diaspore before the low grade material feeds to the Bayer process (Feng et al., 2009 ). Associated gangue minerals in bauxite ores are varied.
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The bauxite is purified by the Bayer Process. First the ore is mixed with a hot concentrated solution of sodium hydroxide. The NaOH will dissolve the oxides of aluminum and silicon but not other impurities such as iron oxides, which remains insoluble. The insoluble materials are removed by filtration. The solution which now contains the oxides ...
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The aluminium compound in bauxite is aluminium oxide and the main impurity is iron (III) oxide, Aluminium is obtained by the electrolysis of aluminium oxide dissolved in cryolite. (i) Name the process used for the purification of bauxite. (ii) Write the equation for the action of heat on aluminium hydroxide.
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Among environmental hot spots all over the world are the tailings of RM, generated during the digestion of bauxite ore with sodium hydroxide by Bayer process for the extraction of alumina. The term 'red mud' is used as a synonym for 'bauxite residue'. The residue generated is usually highly alkaline with pH about [1, 2].
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Name the process used for the purification of bauxite. Write the equation for the action of heat on aluminium hydroxide; Write the formula of cryolite. Answer: (i) (a) Aluminium oxide reacts with NaOH (aq.) at 150200°C to give sodium aluminate which is soluble in water. (b) Iron (II) oxide remains unaffected.
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Therefore, iron oxide and silica are the two impurities of the bauxite ore. Note: The extraction of the bauxite can be done by the process such as Bayer's process and Hall Heroult's process. In Bayer's process, the production of aluminium oxide takes place after which in Hall Heroult's process it pure aluminium is extracted by the smelting ...
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Bauxite processing wastes (red mud) Bayer process is about the production of alumina through the refining of aluminum ore (bauxite). The red mud is insoluble slurry waste that contains different types of oxides. Tremendous amount of this slurry is disposed every year (Marwaha et al., 2018 ). Aluminum, silicon, iron, and calcium oxides are ...
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Purification of Bauxite ore. 1. Name of the purification process. It is the Baeyer's process that is used for the purification of impure oxides of Aluminum. 2. Chemical equations involved in Baeyer's process. The main impurities found in the impure oxide of Aluminum Al 2 O 3. 2 H 2 O are Iron(III) oxide, Fe 2 O 3 and Silica SiO 2.
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Pressure Leaching of Bauxite. In the Bayer process, the crushed bauxite ore is ground in a fine grinding mill. Strong caustic soda solution (130 350 g Na 2 O per liter) is introduced in the mill to obtain a slurry. The resultant slurry is pumped into a horizontal mild steel digester tank (autoclave) heated by steam under pressure with ...
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Bauxite is the most common aluminum ore. Approximately 98% of primary aluminum production is based on bauxite. In the former Soviet Union, aluinite and kaolinite are also used in small proportions for aluminum production. Bauxite is a naturally occurring, heterogeneous material composed primarily of one or more aluminum hydroxide minerals plus ...
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Balanced equations for the purification of bauxite: Al A 2 O A 3 2 H A 2 O + 2 NaOH 2 NaAlO A 2 + 3 H A 2 O. NaAlO A 2 + 2 H A 2 O NaOH + Al ( OH) A 3 ↓. 2 Al ( OH) A 3 → 1000 ° C heat Al A 2 O A 3 + 3 H A 2 O. Concept: Metallurgy.
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By the Bayer Process, the bauxite is purified. The ore is first combined with a hot, condensed sodium hydroxide solution. Aluminium and silicon oxides, but not other impurities such as iron oxides, can be dissolved by NaOH, which remains insoluble. By filtration, the insoluble materials are removed.
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The Bayer process is used for refining bauxite to smelting grade alumina, the precursor to aluminum. Typically, depending upon the quality of the ore, between and tonnes of bauxite is required to produce 1 ton of alumina. The Bayer process involves the digestion of crushed bauxite in the concentrated sodium hydroxide (caustic) solution at
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