SELF-REDUCING OF CHROMITES FOR FERRO -CHROMIUM PRODUCTION: INFLUENCE OF THE COMPOSITION OF THE SLAG.

摘要

The chromites-carbon composite pellets have been used for producing pre-reduced material for charging into Smelting Arc Furnace (SAF) for production of High Carbon Ferro-Chrome (HCFeCr). This work intends to improve the knowledge on the behavior of self-reducing agglomerates of chromites, at high temperature, aiming to produce HCFeCr by directly charging these agglomerates into the smelting furnace. Brazilian fine chromites with approx 40 percent Cr_2O_3 mixed with petroleum coke fines and fluxing agents (CaO and SiO_2) were agglomerated with Portland cement. The expected initial slag composition was composed with addition of fluxing agent to determine the liquidus temperature of the resulting initial slag (1773K and 1923K). The pellets produced were submitted at 1773K and the fractional reaction as a function of time was determined. The results have been shown that pellets containing components which resulted in a liquid slag phase at high temperature presented significant better reduction behavior than that of with pellet which the liquid slag phase was formed at low temperature.