Aluminium is extracted from its chief ore, bauxite. The ore is first purified and then the metal is extracted from it by electrolytic reduction. (a) Write three balanced equations for the purification of bauxite by Hall's process. (b) Name a chemical used for dissolving aluminium oxide. In which state of subdivision is the chemical used?
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(a) When bauxite is treated with sodium hydroxide solution, what happens to (i) the aluminium oxide (ii) the iron (III) oxide (b) (i) Name the process used for the purification of bauxite. (ii) Write the equation for the action of heat on aluminium hydroxide. (c) (i) Write the formula of cryolite.
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The Bayer process is the principal method for the production of alumina from bauxite worldwide. The modern version of the process (developed in the 1880's) still maintains the key steps of dissolution of aluminarich minerals into hot caustic solution, separation of the insoluble phases, followed by gibbsite precipitation and calcination of the gibbsite to alumina (Al 2 O 3).
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Bauxite residues from alumina production. Aluminium production consists of two key stages: The first is alumina refining (Bayer process), which involves the generation of alumina from bauxite ore; the second stage is aluminium smelting (HallHéroult), the process of transforming alumina into Most of the world's alumina is produced using the Bayer process, although minor volumes ...
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Q. Aluminium is extracted from its chief ore, bauxite. The ore is first purified and then the metal is extracted from it by electrolytic reduction. (a) Write three balanced equations for the purification of bauxite by Hall's process. (b) Name a chemical used for dissolving aluminium oxide. In which state of subdivision is the chemical used?
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Sodium hydroxide is added to bauxite ore during purification of bauxite. Bauxite is reacted with a conc. solution of NaOH under pressure for 2 hrs as a first step in obtaining Al 2 O 3. The impurities present in bauxite mainly Fe 2 O 3 and SiO 2 remain unaffected with conc. NaOH as impurities are not amphoteric. Bauxite, being amphoteric reacts ...
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The HallHéroult process is a major industrial process that involves the smelting of aluminium. It involves dissolving aluminium oxide (alumina) obtained from bauxite through Baeyer's process. In this process, pure alumina is mixed with Calcium fluoride (CaF2) or Cryolite (Na3AlF6).
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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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Bauxite is purified by the Bayer process which is the principal industrial refining process. As bauxite contains only about 40 to 50% of alumina, the rest has been removed. This is achieved by washing bauxite with hot sodium hydroxide, which dissolves the alumina by converting it to aluminum hydroxide which forms a solution in a strong base:
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The first step in aluminium processing involves extracting bauxite ore from the ground. Bauxite is a mineral composed mostly of aluminum hydroxide and other compounds like silica, iron oxide, titanium dioxide, and kaolinite. The bauxite ore must be extracted from deep within the earth using heavy machinery such as bulldozers and excavators.
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3. Ironrich bauxite processing and metallurgy. Ironrich bauxite ore usually contains over 40 wt% iron oxide [11, 12], huge reserves are found in Australia, Guinea, Brazil, Laos, Vietnam and China, but they have not yet been used is worth noting that more than billion tons of ironrich bauxite resources have been explored over the last 20 years in western Guangxi, China [13 ...
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The main beneficiation methods of bauxite are washing, flotation, magnetic separation, chemical beneficiation, process of separating concentrates from bauxite ore is actually a process of removing gangue minerals and harmful impurities, and separating highaluminum minerals and lowaluminum minerals to obtain concentrates with a high aluminumsilicon ratio.
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The Bayer process is the principal industrial means of refining bauxite to produce alumina (aluminium oxide) and was developed by Carl Josef Bayer. Bauxite, the most important ore of aluminium, contains only 3060% aluminium oxide (Al 2 O 3 ), the rest being a mixture of silica, various iron oxides, and titanium dioxide. [1]
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Aluminium ore close ore A rock containing enough quantities of a mineral for extraction to be possible. is called bauxite (Al 2 O 3).The bauxite is purified close purified A substance that has ...
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Aluminum Extraction Flowsheet The flowsheet in this study illustrates only the following two steps in the modified Bayer Process: grinding and digestion of bauxite in the sodium aluminate liquor, separation and washing of the coarse red mud residue from the sodium aluminate liquor.
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General Chemistry: Principles and Modern Applications. Ralph H. Petrucci, F. Geoffrey Herring, Jeffry D. Madura, Carey Bissonnette 11 Edition
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Gallium has become increasingly popular as a substrate material for electronic devices. Aside from ore, gallium can be obtained from such industrial sources as the Bayer process caustic liquor that is a byproduct of bauxite processing, flue dust removed from the fumecollection system in plants that produce aluminum by the electrolytic process, zinc refinery residues, gallium scrap materials ...
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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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Aluminium is extracted from its chief ore, bauxite. The ore is first purified and then the metal is extracted from it by electrolytic reduction. (a) Write three balanced equations for the purification of bauxite by Hall's process. (b) Name a chemical used for dissolving aluminium oxide. In which state of subdivision is the chemical used?
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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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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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A material supplier from Belgium would like to produce limestone powder for his custome...
India is rich in various mineral resources and it is an important mineral processing market
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