How To Make Aluminum Foil?

Answer 1

In order to make aluminum foil, first obtain aluminum-containing ore. The most important aluminum-bearing ore is bauxite, which contains a mixture of aluminum oxides with iron oxides and clay minerals. Australia is currently the greatest producer of bauxite, although it is also mined in great quantities in China and Brazil. Bauxite is most commonly mined by a process known as strip mining, as it is often found close to the surface of the ground, not buried under large quantities of rock, soil, or other elements.

Next, refine the aluminum-bearing ore to produce the raw element. The first step of this refining extracts the aluminum oxides from the other minerals and elements in the ore. These minerals and elements include iron oxides, clay minerals, and common impurities such as silica and water. The second step, smelting, processes the aluminum oxides, commonly referred to as alumina, into pure aluminum. In the modern day, this is usually accomplished by electrolysis. Take the molten alumina and places it in a smelting cell with a liquid aluminum compound known as cryolite. Run an electrical current through this mixture while in the smelting cell, which will deposit purified molten aluminum at the bottom of the smelting cell, while the oxygen from the aluminum oxide will escape the cell as carbon dioxide.

At this point, once the aluminum is removed from the smelting cell, it can either be utilized in its pure state, or mixed with various other elements and minerals to form useful alloys. While these alloys have many purposes, aluminum foil is best made with almost entirely pure elemental aluminum. Anneal ingots of the purified aluminum by repeatedly treating them with heat, a process which will make the metal more workable and more easily formed into foil.

To form aluminum metal into aluminum foil, the most productive method is to roll the aluminum between two metal rolls known as work rolls, between which the aluminum is compressed and then extruded as thin sheets. By adjusting the space between the work rolls, one may control the thickness of the aluminum foil which is extruded. Finally, the extruded foil should be trimmed to have regular, even edges.