increasing drying efficiency by modifying the design of feed chute of the gol-e-gohar pelletizing plant ball mill

Pelletizing plant of the gol-e-gohar mining and industrial company consists of a burner, a dry ball mill (6.2 m × 13 m), and an air separator. the ball mill consists of a 2 mlong drying and an 11 mlong grinding chambers. the iron ore concentrate is fed to the drying chamber by a feed chute. it was found that when the feed moisture content increased from 1.3% to 3.5%, the throughput decreased by 12% (35 t/h) indicating a low performance of the dryer. monitoring the wear rate of flights for a period of 12 months showed that the first 0.8 m (59%) length of the dryer length did not experience any wear. to overcome this problem, various feed chute designs with different geometries were simulated by the kmpcdem© software. with the aim of arriving at a proper material trajectory, where the total length of the dryer is used, a new feed chute was selected. the simulation results indicated that if the height of the feed chute is increased from 1.60 to 2.26 m and the slope is increased from 45 to 48 degrees the material arrives at the first 0.48 m of the drying chamber. in this manner, the unused part of the drying chamber decreases from 59% to 36% of the length. after installation of the new feed chute during a period of three months, the throughput increased by 36 t/h.