Correlation between the cold compression test and abrasion resistance test (astm e 279-97) in self-reducing pellets

Mechanical properties are very important on development of self-reducing technologies of iron ore raw materials. In order to use the self-reducing pellets, is necessary to improve their mechanical stresses and abrasion resistance. In the iron ore reduction processes, the self-reducing pellets need to present a good cold crushing strength to support the material column weight within the blast furnace, or need a wear resistance when they are being transported or handled in a rotary kiln; In this work, the cold compressive strength and resistance to abrasion were measured in terms of the graphite concentration. The abrasion resistance was measured by tumbler test (ASTM 279-97). It was prepared different self-reducing pellet of 17 mm diameter, containing iron ore, graphite and with 10% mass of Portland cement High Initial Strength (HIS). The cement was kept constant at level of 10% and iron ore plus graphite proportions was changed from 90/0 up to 0/90 respectively. This selected method enables a more uniform variation of the mechanical strength of the pellets, keeping constant the amount of cement. It was obtained compressive strengths of mixtures, testing 10 samples for each composition of pellets. Samples were tested in the tumbler, adjusting the drum volume to sample quantity and was measured the amount of retained material in the 6.3 mm mesh sieve. The results with increasing graphite content presented a decrease on compressive strength and increase on abrasion resistance.