Study of Iron Ore Mixtures Behavior in the Grinding Pelletizing Process

The main unit operations of pelletizing process are grinding, filtering, pressing, pelletizing, and firing. Grinding, the first operation in the process, is a crucial step for the subsequent operations. Three iron ore mixtures with different grindability index (low, medium, and high) were used in order to verify the influence in the operational parameters such as production rate, discharge density, and pump pressure. Through Design of Experiments (DOE), nine experiments over each iron ore mixture were done, varying the minimum and maximum grinding operational parameters. Independent variables (responses) were the specific surface area or Blaine index (BI) and the particle size (PS), which were measured by the automatic PS analyzer system (PSI). The main objectives of this study are to know the behavior of iron ore mixtures with different grindability indexes in the industrial plant and develop a regression model that can be used for real-time measurement of PS and BI for different grindability indexes in the industrial operations. The results showed satisfactory correlations between the factors and responses.