• Primary aluminum is produced by electrolysis or "smelting" of alumina, a process discovered in 1886, at the same time, but independently, by a French man, Paul Héroult, and an American, Charles Martin Hall.This process is then known as the “Hall Heroult” process.
   
•  Aluminum obtained by electrolysis is naturally rich in impurities contained in the raw materials (notably alumina and electrodes), mostly iron and silicon.
  
• The process consists of the reduction by electrolysis of alumina dissolved in a molten bath of cryolite (a sodium aluminum fluoride) in a reduction cell or "pot" lined with carbon. Powerful electric currents are passed through the cell (up to 300 kA).
  
• A luminum obtained by electrolysis is naturally rich in impurities contained in the raw materials (notably alumina and electrodes), mostly iron and silicon, ans some Titanium, Vanadium, Nickel, Gallium, Zinc.
  
• The common commercial standards confine themselves to a purity standard of more than 99.7%
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• However, industry and particularly the field of electronics has shown greater and greater needs for purity standards exceeding 99.9%.

• PECHINEY HIGH PURITY is managing several processes so to purifiy, casting and changing the shapes of the delivered products.
• Pechiney High Purity is the only worldwide producer who can guarantee traceability for its high purity metal from ore extraction down to the sale of its ultra-pure billets.
  
•  Pechiney High Purity controls all the processing stages of the High Purity Aluminum as an integral part of the firm Aluminum Pechiney .  It can therefore guarantee full traceability all the way to the final product.
  

• All producers of 5N quality aluminum use 3 layers refined aluminum as their basic feed material and subject it to one or more additional purifications using the fractional crystallization process, which consists either of a zone-melting additional operation or a segregation operation.
  
• Both of these techniques make it possible to lower the amount of impurities below 10 ppm (1 ppm when necessary) but only the segregation technique is able to consistently eliminate Uranium and Thorium to sub ppb levels.
  
• After purification, the metal is solid. It is remelted, cast into billets and analyzed for sale in its pure state.
  
• Other elements such as Silicon and Copper can also be added during the melting operation. Alloyed billets are made by vertical continuous casting using the Pechiney "Grain control" process to ensure a fine isotropic structure

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• T he billets are cut into "pre-forms", which generally undergo thermomechanical processing. The rough forging obtained in this process is then machined, surface finished and fixed to a support called a "backing plate".
• P echiney High Purity is a manufacturer and a supplier of high purity alloys, and not a target manufacturer.