No aluminium no zinc. It protects steel from corrosion and provides the same protection for sheet metal used in automobiles as it does for roof gutters. Zinc oxide makes paints shine, is used to treat wounds as well as an ingredient in sunscreens, and in batteries it supplies us with energy.
Besides playing an important role in our daily lives, zinc is actually essential for human, animal and plant life. People need zinc for their metabolism, growth and brain development. Zinc strengthens the immune system, protects the skin and is essential for our reproduction. In short: zinc is indispensable.
What does AMAG have to do with zinc, you ask? Two things: Zinc is an important alloying element in high-strength aluminium alloys and without aluminium cathode sheets there would be no zinc production (about 14 million tons of zinc are produced annually).
Around 90 % of the zinc produced worldwide by smelting is obtained wetchemically using the hydrometallurgical process. In this process, aluminium and lead sheets are immersed in a sulfuric acid solution (electrolyte), which, depending on the smelter, may also contain recycled zinc.
The lead sheet acts as the anode and the cold-rolled aluminium sheet as the cathode. Depending on the smelting process, a zinc layer of sufficient thickness for further process steps is deposited on the surface of the aluminium cathode over a period of 24 to 48 hours by electrochemical processes.
The elementary zinc adhering to the aluminium sheet is mechanically removed from the cathode in a process known as stripping; it is then cleaned, re-melted in smelting furnaces and cast for further use, usually in ingot form. The aluminium cathode sheets then go back into the electrolyte solution and are used again for zinc production. A single cathode sheet can thus be reused hundreds of times over the course of its service life, which can be several years. Apart from its corrosion resistance and electrical conductivity, aluminium is used as a cathode sheet because of its favorable effect on hydrogen overvoltage, which makes the extraction of zinc by hydrometallurgy possible in the first place.
THE ADVANTAGES OF AMAG PROCATH®
- optimal conductivity
- increased strength
- excellent form tolerances
- patented edge strip technology with unmatched quality
- extremely tight form tolerance
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