Abstract:
The pelletizing plant in São Luís presents significant losses (close to 30%) in pellet production due to the high humidity of the ore that supplies the plant. The heavy rains, typical of the region, which occur from January to June, increase the humidity in the piles of ore formed in the mine, during transport in wagons and in the piles of ore during pelletization. The consequences are obstructions in silos, kicks, overloads on belts, slipping of press rollers, poorly formed pellets, etc. In order to improve the handling of this ore with high humidity and improve its pelletability, a superabsorbent input capable of retaining excess moisture in the ore was identified on the market. This input, known as Sodium Polyacrylate (PAS), is a Superabsorbent Polymer (PSA) and has the capacity to absorb process water in a proportion between 240 and 260 times the value of its mass. Through laboratory, pilot and industrial scale tests, it was observed that the dosage of this superabsorbent before mixing makes the ore handling more stable, easier to sift, transport and press. Even with humidity at 11.6%, the sieve and roller press did not demonstrate the problems of loss of production, obstruction/slippage of the press rollers, generating pellets with excellent finishing and quality.