To produce zinc oxide, we can use three different processes. Two of them are thermal processes and the third one is a chemical process.
One of the thermal processes is called the indirect process, or French process, in which zinc oxide is obtained from zinc metal. This is the method used by A-ESSE in our Carasco plant.
The other thermal process is the direct process, or American process, in which residue containing zinc is used. Both processes produce a zinc vapor which is combusted in a controlled atmosphere and transformed into zinc oxide.
Zinc oxide is also produced through a chemical wet process through the precipitation of zinc carbonate, basic carbonate, or zinc hydroxide. It is then purified, filtered and dried. Zinc oxide is then obtained by roasting the precipitate.