Computational investigation of roasting characteristics of zinc sulfide concentrate in an industrial-scale 123 m2 fluidizing furnace

Fluidized roasting furnaces are commonly used in the roasting of sulfide ores during the zinc extraction process. However, these furnaces encounter challenges such as fluidization instability, dead zone formation, and abnormal sintering. This study applies the MP-PIC method to analyze the gas-concentrate roasting characteristics in an industrial-scale 123 m2 fluidized roasting furnace, with model accuracy validated through experimental comparison. The results reveal that particle back-mixing causes the particle velocity near the wall to be significantly lower than that at the center of the furnace, with this effect becoming more pronounced at lower heights. Both gas and particle horizontal velocities are higher in the gas outlet area. The particle velocity in the freeboard region increases with gas flow rate. High particle slip velocities are found near the small gas inlet area at the furnace bottom and close to the bed surface. Meanwhile, the particle temperature above the small gas inlet is markedly lower than that observed above the large gas inlet. Moreover, oxygen concentration rises with the gas flow rate but decreases significantly at higher operating temperatures.