How is Aluminum Plate made-

 

The Aluminum Plate manufacturing process can be divided into three phases; the first bauxite, which contains aluminum, is extracted from the ground. Bauxites are transformed into alumina or aluminum oxide and finally, in the third step, pure aluminum is produced using electrolytic reduction, a process in which aluminum oxide is broken down into its components using electric current. Almost  about 45 tons of bauxite is made into two tons of alumina from which about one tons of aluminum can be manufactured.

Many minerals are available in the world, whose aluminum can be done, but the most common raw materials are bauxite. Bauxite is a mineral composed mainly of aluminum oxide mixed with other minerals. Bauxite is considered high quality if it contains more than 50% aluminum oxide.

v  v  Bauxite supplies-

·         Confirmed global bauxite supplies are estimated at 18.6 billion tons. At the current level of extraction, this should last for more than a 100 years.

·         There is a lot of variation in bauxites. Structurally they can be solid & dense or crumbly. The usual color is brick red, flaming red, or brown because of iron oxide. If iron content is low, bauxite can be grey or white. But yellow, dark green and even multi-colored bauxites with bluish, purple, red, and black strains occur too.

·         About 90% of the world’s bauxite supplies are found in the tropics and subtropics, with 73% in just five countries: Guinea, Brazil, Jamaica, Australia, and India. Guinea has the largest supply of bauxites, 5.3 billion tons (28.4% of the global supply) & the Guinean bauxites are very high quality, containing minimal amounts of admixtures. They're also found very near to the surface, which makes mining them very easy.

 

v  Production of Aluminum Plate-

·         The next stage in the production chain is the processing of bauxite into alumina or aluminum oxide - Al₂O₃, - a white powder. The most popular process for making alumina from bauxite is the Bayer process, first discovered over 100 years ago but still widely used today. About 90% of alumina refineries in the world use the Bayer process. It is very effective but can only be used on high-quality bauxite with a fairly low additive content, especially silicon.

·         Bayer process is as follows: the crystallized aluminum hydrate found in bauxite easily dissolves in concentrated caustic soda (NaOH) at high temperature and when the temperature drops and the concentration of the solution rises, the aluminum hydrate crystallizes but the other elements contained in the bauxite either doesn't dissolve or recrystallize and settle to the bottom well before aluminum hydrate crystallizes. This means that once the aluminum hydrate is dissolved in the caustic soda, the ballast can be easily isolated and removed. This ballast is called red mud.