Different ways of manufacturing aluminum Research Paper

Different ways of manufacturing aluminum - Research Paper Example minum has thousands of different applications particularly in construction and manufacturing sectors and â€Å"more than 10 billion pounds of aluminum are produced worldwide annually† (Lindamood n. d.). The most commonly found aluminum ore bauxite is a mineral of aluminum (Al) and hydroxyl (OH) with very strong covalent bounding between oxygen and aluminum. Hence on large scale, it is not possible to directly extract Al from its ore by simple chemical process. The separation is carried out through various indirect methods. The manufacturing of pure aluminum (lxx.x, 99.00% or greater) from its ores is done through following process as given below. Also known as ore separation/purification process is invented by an Austrian chemist Carl Josef Bayer while working at Saint Petersburg, Russia. In this process, after mining, the ore is mechanically crushed into very fine granular form. The fine powdered ore is then mixed in hot caustic soda liquor (NaOH) at 110-270 °C under 340 kPa Pressure to produce slurry of liquid. After several hours of process NaOH completely dissolves the Al. The liquid is then passes through a series of flash tanks to reduce the pressure and to recover the heat. The mixture is separated from its solid impurities by passing it through a settling tank and through filtration process. The saturated aluminum rich liquid passes through a series of six-story-tall precipitation tanks (Hall 1997). As the liquid propagates through each tank, seed alumina hydrate crystals are also added from the top of each tank. The â€Å"aluminum trihydrate crystals grows in size and precipitated calcined in rotary kilns or flui dized bed calciners to produce alumina (Al2O3)† (Aluminum Manufacturing 1998: pp.261).The crystals obtained through kiln are cool down and proceed to smelting process. In Hall-Heroult Process also known as smelting processing the alumina crystal abstained through Bayer process is further dissolved in molten cryolite at a temperature of 960-970 ° C