Iron ore tailings dry stacking in Pau Branco .
Vallourec's beneficiation plant produces concentrated iron ore lumps and fines in Pau Branco mine . Tailings are composed of both fines (>45 μm) and ultra-fines (<45 μm). Ultra-fines are generated from the de-sliming cycloning of the magnetic concentration process, and fines are the rejects of this process.