Effect of Ti-V Magnetite Concentrate Pellet on the Strength of Green Pellets and the Quality of Sinter by Composite Agglomeration Process (CAP)

The composite agglomeration process is one of the most potential methods to effectively produce blast furnace burden with vanadium-titanium magnetite. In this work, the effects of V-Ti magnetite particle size, coke breeze ratio of green pellets, coke breeze of pelletized feed, and pelletized feed basicity on quality of CAP products were studied. The results shown that the drop strength and compressive strength of green pellets are improved when the vanadium-titanium magnetite is pretreated by high-pressure grinding roll compared with those prepared from raw material. With the increase of basicity of flux green pellets, the strength of green pellets, the permeability of mixed layer and the sinter yield increase. When the basicity of green pellets is 0.9, the economic and technical indexes of sintering are the best. After finely grinding coke powder for sintering and adding vanadium-titanium magnetite to prepare carbon-containing green pellets, the amount of coke powder should be controlled at about 0.4 mass%, considering the drop strength and compression strength of green pellets,. However, sintering with pellets containing 0.4% coke breeze in the core produces perforated pellets or molten pellets. Therefore, it is not recommended to use coke powder in CAP pellet.