Dry Iron Ore Fluidization, Flowability, and Handling: Supporting Dry Processing of Iron Ores and Guiding Industrial Designing

Renewed interest in dry processing has arisen due to challenges in water management. In dry iron ore beneficiation, flowability of bulk solids is a key concern, leading to issues like plugging and clogging in bins and chutes. Handling also faces challenges from environmental regulations, particularly regarding dust emissions. Enclosed conveyor technologies, such as air-assisted conveyors that use fluidization, offer effective solutions, though the maximum particle size that can be conveyed is a limitation that needs consideration. This paper examines how the size and chemical composition of bulk iron ore materials affect their handling behavior. By employing Geldart’s and Jenike’s methods, this document provides technical parameters and recommendations, which are lacking in the current literature, for the designing of dry processing plants. Findings indicate that ultrafines can have a flow function as low as 2.05, indicating cohesive behavior even when dried, while fluidization tests support these characteristics. In contrast, coarser fractions are easy for free-flowing materials. Samples with a top size of 0.5 mm fall between sand-like and spoutable groups in Geldart’s classification. Denser materials did not fluidize, while less dense ones did. Thus, air slides should avoid handling materials at this threshold and focus on finer materials. This paper offers guidance for designing dry processing plants to address handling bottlenecks.