Aluminum is a silver-white metal and ranks third in the earth's crust after oxygen and silicon. The density of aluminum is relatively small, only 34.61% of iron and 30.33% of copper, so it is also called light metal. Aluminum is a non-ferrous metal whose output and consumption are second only to steel in the world. The density of aluminum is only 2.7103g/cm3, which is about 1/3 of the density of steel, copper or brass. Because aluminum is light, it is often used in the manufacture of land, sea and air vehicles such as cars, trains, subways, ships, airplanes, rockets, and spacecraft to reduce its own weight and increase the load.
The production of aluminum ingots is composed of bauxite mining, alumina production, and aluminum electrolysis. The bauxite ore is first mined, and aluminum ore powder is produced through the processes of water washing and grinding, and then alumina is obtained through four complex processes such as roasting. There are three main types of bauxite for the production of alumina: gibbsite, water diaspore, boehmite. Generally, the purity of aluminum ingots is relatively high, and the casting becomes a fixed shape, which is convenient to calculate the price and weight.
There are two types of aluminum billets: one is the solidified aluminum block after alumina electrolysis, and the other is cast into a specific shape according to certain requirements when the finished product is produced. Generally speaking, the aluminum billet is a specific aluminum block manufactured for the subsequent process, and the aluminum ingot is a measurement unit of a fixed specification and a fixed purity.