China Nonferrous Metallurgy

Panzhihua iron and Steel Group‘s Xichang strip roaster production line is the first production line of vanadium-titanium ore strip roaster pellets in China, the average compressive strength of the finished pellets was lower than that of the original pellets, per pellet only ≥1950N. This paper analyzes the reasons from the aspects of raw material structure, pelletizing process, technological operation of belt roaster, etc., the optimization measures adopted include: controlling the mass fraction of TiO₂≤12%, V₂O₅≤1%, Al₂O₃＜2.0%, MgO＜1.8%, and the concentrate particle size of 200 mesh 75%~80%, the alkalinity should be controlled about 0.6 times, the proportion of bentonite should be reduced to 1.2%~1.4%, the proportion of green ball particle size 10~12.5mm≥60%, the proportion of gravity dust ＞1.5%, or the proportion of Sintering Machine Head dust ＞1.5%, The operating regulations of the roaster is as follows: the temperature of the drum drying section is 300~330℃, the temperature of the drying section is 370~390℃, the preheating temperature gradient is 500→1200℃, the temperature of the roaster section is 1230~1240℃, and the oxygen content in the hood is 17.3%~18.0%. After optimization, the average compressive strength of single pellet was about 2348N, and the smoke dust content was 2.54mg/Nm₃, SO₂ content was 3.13mg/Nm³, NO_x content was 41.42mg/Nm³, and the reference oxygen content was 17.54%, all meet national emission standards.