3. Description of a zinciferous waste processing unit

TREZ (Traitement Revalorisation Électrolytique du Zinc), an RVX subsidiary, was set up in 2001 to operate the process described above. In partnership with various manufacturers, notably Galva 45, Ferco International, Marquet and SNDCE, and with the support of ADEME, Agence de l'Eau RMC, CETIM, Région Rhône-Alpes and SATS, the company set up its first industrial unit at Aiguebelle (73).

The treatment capacity of this unit is around 20,000 tonnes per year of zinc-bearing waste, primarily metal hydroxide cakes, at a treatment cost of around 120 euros per tonne or less, depending on the zinc content of the waste. The unit should be able to co-process 4,000 tonnes a year of spent galvanizing acid (pickling acid or electro-zinc bath). At full load, the unit will produce 3,000 tonnes of zinc powder per year, part of which (around 5%) is reused in the cementation process....