INFLUENCE OF CARBON CONTENT ON MECHANICAL PROPERTIES OF IRON ORE PELLETS

Abstract

Solid fuels are added during the pelletizing process in order to reduce the natural gas consumption in the firing process and to obtain better temperature distribution inside the pellets for its induration. The purpose of this research was to evaluate the effect of the amount of carbon added to mixtures containing different types of pellet feed on the mechanical strength. The pellet mixtures were prepared with different dosages of anthracite (1, 1.2 and 1.4% of fixed carbon) and two different sorts of pellet feed. The mixing, pelletizing and firing stages were done on a pilot scale, and the fired pellets were subjected to the mechanical properties evaluation and microstructural analyses. It was found that when increasing the amount of anthracite, the compression and tumbler strength of the fired pellets decreased, which seemed to be related to the formation of a large number of pores and magnetite in the core of the pellets. When a larger amount of porous hematite and goethite were used in the pellet feed, larger quantities of magnetite were found in the microstructure of the pellets.