Aluminium Extraction from the Lithosphere Essay Sample
Aluminium Extraction from the Lithosphere Essay Sample

Aluminium Extraction from the Lithosphere Essay Sample

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  • Pages: 3 (624 words)
  • Published: August 22, 2018
  • Type: Research Paper
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In the geosphere, the content of aluminum is substantial and varies between 7.5% to 8.1% among metallic elements.

Deviation from its intended trajectory is rare as the element has a strong attraction to oxygen owing to its high reactivity, leading to a powerful connection with O. This makes separation challenging. Hence, it must undergo the refining process utilizing aluminum oxide and following the Hall-Heroult procedure, presented below.

The pyrogenic stone bauxite, which has an orangish-red color, has two functions when it is acquired through the Bayer Process to make alumina. Alumina is used for both manufacturing aluminum metal and as a durable material that retains its strength even at high temperatures. This versatile substance is often used to line furnaces, kilns, incinerators, and reactors.

The geosphere contains a specific type of waste material called dross, which consists of different substances such as

...

aluminum oxide (Al2O3), clay, iron (III) oxide (Fe2O3), silica (SiO2), and titania (TiO2). The dross comprises 30-54% aluminum oxide.

Australia accounted for approximately one-third (33%) of the worldwide bauxite production in 2007. The extraction of aluminum oxide from bauxite is primarily carried out through the Bayer Process, a prominent industrial technique. This process involves purifying bauxite by subjecting it to a heated solution of sodium hydroxide (NaOH) at a temperature of 175°C, which effectively dissolves the aluminum and silicon oxides present in it.

The solid dross is filtered out to further purify the solution. Infusion of carbon dioxide gas into the solution creates a weak carbonaceous acid, which neutralizes the solution and causes aluminum oxide precipitation.

However, it is important to remove other silicon impurities. To do this, the remaining solution is filtered once more and then boiled t

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eliminate the water content. The end result is purified aluminum oxide. Once the purified aluminum oxide has been obtained, the aluminum can be extracted from it using a process called The Hall-Heroult method. In this method, the aluminum oxide is dissolved in liquefied Greenland spar (Na3AlF6) and then heated to approximately 980oC.

this is much lower than the typical temperature needed to operate aluminum oxide due to the inclusion of aluminum fluoride, resulting in significant energy savings. The mixture is then placed in a C lined bath and subjected to a high electrical current.

The process involves the formation of aluminum at the cathode and oxygen gas at the anode. The reaction between the oxygen gas and the anode produces carbon dioxide gas. The transformer produces a current ranging from 220kA to 340kA, with an electromotive force of 1-2kV from 110kV. This demonstrates the strength of the bonds between the aluminum and oxygen ions. The resulting solid aluminum is denser than the liquefied Greenland spar at 1000°C, causing it to sink to the bottom of the bath and be removed.

The vacuity tubing called a syphon is used to remove the liquid aluminum, thereby avoiding the need for high energy pumps. The solid residue from the Bayer Process is referred to as ruddy clay, which poses a challenge for disposal due to its high pH values exceeding 13.

2. To neutralize the solution, saltwater can be used. The resulting H2O will have a pH below 9.0 and can be safely returned to the sea.

The electrolysis procedure created exhaust, primarily carbon dioxide, which was released into the fume hood. Hydrogen fluoride (HF) was generated from Greenland spar, a very

corrosive gas that reacts with glass.

These gases, which are covered in plastic, are treated in a nearby works. The works dissolves the HF into H2O to neutralize it, which means that the pollution and large amounts of energy required to do so was a problem in the past. However, the use of improved filter systems and hydroelectric power works has somewhat resolved this issue.

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