CRYSTALLIZATION BEHAVIOR OF CALCIUM FERRITE DURING IRON ORE SINTERING

摘要

Crystal precipitation behavior of calcium ferrite (CF) during iron ore sintering process along with the effect of cooling rate, SiO_2 and AI2O3 on crystalline condensation were studied. The results show that CF, has strong ability of precipitation. The precipitation is barely affected by extenal factors. It begins to precipitate when the liquid phase cools down to about 1200℃. CF could crystallize rapidly at the cooling speed of 150 ℃ /min. Furthermore, decreasing of the cooling rate favors the development of crystal. Binder phase transformed from CF system to silicate system when SiO_2 content was increased to 5~6%, with a constant basicity (R) 2.0. Increasing Al_2O_3 content could promote the precipitation of CF and the development of crystal.