Modelagem e simulação de um forno rotativo utilizado para o endurecimento de pelotas de minério de ferro

Abstract

Iron ore pellets are thermally processed in industrial furnaces, and this process is crucial for achieving the proper mechanical strength. All the properties of the agglomerates are obtained during the firing stage, which is decisive for the quality of the final product. In the current industry, there are several systems used for hardening iron ore pellets through firing. Among these systems, the rotary kiln stands out due to its high energy efficiency, and its structure contributes to the reuse of thermal energy from later stages. This allows the pellet to reach high temperatures, consuming less fuel compared to other systems with the same purpose. Large-scale industrial processes increasingly demand the use of technology to assist in controlling and maintaining product quality. It is of utmost importance to study and evaluate the impacts caused by making changes to a process already in operation. For this purpose, process modeling and simulation, using numerical models derived from plant data, become suitable tools. This work presents a numerical model representing a rotary kiln used by a steel company, developed in the Python language. The main objective of the model is to allow, through phenomenological equations, the simulation, prediction, and evaluation of temperature profiles of the main components involved in the process: the pellet and the drag gases for thermal exchange, in addition to considering the furnace walls and the fuels used as an energy source. The results obtained by the model for the thermal profiles were compared with the actual temperature data of the pellet at the entrance and exit of the furnace, obtained from the plant. The results showed very close values, indicating that the model accurately represents the process, with an approximate deviation error of 4%.