Secagem de minério de ferro em vagões e pilha: experimentos e simulação computacional

Abstract

Dust emissions resulting from handling and transporting particulate materials are a problem in the mining industry. These emissions are more accentuated when the materials are not very humid because the reduced humidity makes the particles lighter and more susceptible to dispersion. Faced with these issues, this study proposes a methodology for the theoretical and experimental study of the drying process that occurs when iron ore fines are transported in wagons or stored in piles in the open. The objective is to clarify the effect of surface moisture in the process of dragging wind iron ores on moist surfaces, such as those found when transporting iron ore in open wagons and in ore pile storage yards. In this study, wind tunnel tests were carried out using a wagon model with fine iron ore and an iron ore pile model. A fixed bed drying study at low velocity is also presented using a wind tunnel dryer. A numerical CFD model was developed, and the results agreed well with the experimental results. The numerical model allowed the evaluation of the drying behavior for different values of air flow velocity. Through the established study methodology, it was possible to map the distribution of internal moisture in the bed, which helps to understand the dynamics of the drying mechanism and how this can influence the emission of particles on the surface moisture of these materials.