Avaliação em escala piloto do comportamento dos produtos pellet feed, pellet screenings e micro pellet em substituição ao sinter feed em uma mistura de sinterização

Abstract

Pilot scale sintering experiments were performed, aiming at comparing the quality of the sinter produced from a reference sintering blend with that of sinters resulting from other blends, in which the sinter feed in the reference blend was replaced by 50% and 100% pellet screenings and micro pellets and also by 25%, 50%, and 100% pellet feed. The following parameters of the sinters were assessed: a) production: granulation index, sintering time, < 5mm return, total return, coke rate and productivity;b) quality: shatter index, tumble index, RDI and reducibility; c) sinter structure: microstructural analysis. The results showed that pellet feed may reach 6.25% in a sintering blend (25% substitution). The productivity in the sintering experiments was technically equal to that achieved with the reference blend. The quality indexes and the structure also did notshow significant differences. Pellet screenings and micro pellets may participate up to 12.5% in the sintering blend (50% substitution). The productivity in the sintering experiments was technically equal tothat achieved with the reference blend. The quality parameters shatter index, tumble index, RDI and reducibility reached levels slightly inferior to those achieved with the reference blend. In the case of micro pellets only the parameters shatter index and RDI stayed slightly below the levels for the reference blend. All the quality parameters may be improved with a higher addition level of coke, for the fuel consumption was lower than that for the reference blend