In this process, the ore is first dissolved in a solvent at a particular temperature. For bauxite, the solvent is 45% NaOH solution and the temperature is 473573K. Let us take a look at the reactions involved. In the solution, the ore reacts with Sodium hydroxide and water.
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During metallurgy of aluminium, when bauxite (powdered ore) is treated with concentrated NaOH, sodium aluminate (Na[Al(OH 4]) is formed and impurity (SiO 2) present in bauxite dissolves by forming sodium silicate (Na 2 SiO 3). The separation of the alumina from the impurities in the bauxite ore is usually accomplished by the Bayer Process.
Aqua Regia is a mixture of conc. HCl and conc. HNO 3 in the ratio ... Bauxite ore is powdered and heated with sodium hydroxide under high pressure for 2 to 8 hours at 140 °C in the digester. ... Describe Hall's process for concentration of bauxite. Answer: In Hall's process the ore is powdered and then it is leached by heating with aqueous ...
(a) Bauxite is heated under pressure with conc. caustic soda (NaOH) for 2 to 8 hours. Bauxite dissolves and forms sodium meta aluminate because of the amphoteric nature of aluminium, leaving behind insoluble impurities called red mud. Red mud consists of ferric oxide, sand, etc. which are removed by filtration.
bauxite, rock largely composed of a mixture of hydrous aluminum is the principal ore of aluminum.. Bauxites vary physically according to the origin and geologic history of their deposits: some deposits are soft, easily crushed, and structureless; some are hard, dense, and pisolitic, or pealike; still others are porous but strong or are stratified or largely pseudomorphic after ...
Bauxite ore is the world's primary source of aluminum. The ore must first be chemically processed to produce alumina (aluminum oxide). Alumina is then smelted using an electrolysis process to produce pure aluminum metal. Bauxite is typically found in topsoil located in various tropical and subtropical regions. The ore is acquired through ...
Also known as enrichment, the concentration of ores is the method of removing impurities and other unwanted particles from the ore. The removal method of the gangue particles or the unwanted particles depends on the difference in physical or chemical properties of the ore and the impurities. The minerals present in ores are found in the form of ...
The conventional process of bauxite ore dressing consists on the removal of natural mud . ... in the Bayer process) and reactive silica (kaolinite), cons isted of bauxite digestion i n alkaline .
The ore is dug out from the opencast mines and contains aluminium oxide. The bauxite ore is purified to yield a white powder from which aluminium is extracted. The process of its extraction is done by electrolysis. Usually, bauxite ore is heated in a pressure vessel along with a sodium hydroxide solution at a temperature of 150 to 200°C.
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?
Aluminium production begins with bauxite, the "aluminium ore", which is mined primarily in tropical and subtropical areas, the largest bauxite deposits found in Guinea, Australia, Brazil and Jamaica. ... This bauxite is subjected to the Bayer process for the extraction of aluminum hydrate, most (90%) of which is calcined to produce alumina ...
Bauxite is concentrated by:A) Chemical methodB) RoastingC) Magnetic separationD) Froth flotation process. Ans: Hint: We know that ores of different metals are concentrated by different methods based on the difference between the physical properties o...
Bauxite ore is the world's primary source of aluminum. The ore must first be chemically processed to produce alumina (aluminum oxide).This video was created ...
Bauxite is naturally insoluble in natural solvents. As a result, the addition of caustic alkali to bauxite is crucial for the extraction of aluminium. Bauxite dissolves in caustic alkali to generate soluble sodium meta aluminate, while impurities remain insoluble and precipitate as red mud. Suggest Corrections. 8.
Bauxite is the principal ore of aluminium. The impurities present in bauxite are SiO2, iron oxides and titanium oxide (T iO2). Concentration is carried out by heating the powdered ore with a concentrated solution of NaOH at 473 523 K and 35 36 bar pressure. This process is called digestion. Al2O3 is extracted out as sodium aluminate.
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.
View Solution. Q 5. 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.
Assertion (A) Order of the reaction can be zero or fractional. Reason (R) We cannot determine order from balanced chemical equation. (a) Both assertion and reason are correct and the reason is correct explanation of assertion (b) Both assertion and reason are correct, but reason does not explain assertion. (c) Assertion is correct, but reason is incorrect (d) Both assertion and reason are ...
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
Vast amounts of red mud are produced at bauxite processing plants and stored in lagoons, often formed by flooding playedout bauxite pits when the ore is processed close to where it was mined.
(ii) 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 ...
One way of concentrating the ore is by chemical separation. For example, the separation of aluminium (Al) from the bauxite ore. This process of separating aluminium from the bauxite ore is also termed Bayer's Process. Hot NaOH reacts with the bauxite ore which leads to the formation of sodium aluminate which is watersoluble.
Leaching (metallurgy) Leaching is a process widely used in extractive metallurgy where ore is treated with chemicals to convert the valuable metals within into soluble salts while the impurity remains insoluble. These can then be washed out and processed to give the pure metal; the materials left over are commonly known as tailings.
Reddishbrown bauxite Bauxite with US penny for comparison QEMSCAN mineral maps of bauxite oreforming pisoliths. Bauxite is a sedimentary rock with a relatively high aluminium content. It is the world's main source of aluminium and consists mostly of the aluminium minerals gibbsite (Al(OH) 3), boehmite (γAlO(OH)) and diaspore (αAlO(OH)), mixed with the two iron oxides ...
The ore is first converted into pure aluminum oxide by the Bayer Process, and this is then electrolyzed in solution in molten cryolite another aluminum compound. The aluminum oxide has too high a melting point to electrolyse on its own. The usual aluminum ore is bauxite. Bauxite is essentially an impure aluminum oxide.
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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