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.
1 July 2018 in REM - International Engineering Journal
The induration furnace is one of the most important devices in the pellet production system. It is responsible for ensuring the quality of pellets produced, since a high level of thermal energy is necessary to reach the physical properties needed. Therefore, the refractory lining performance is important to guarantee the quality of pellets and to avoid thermal losses. Minor failures in the refractory lining may result in serious damage, if it not previously identified and repaired. This article was written to explain a preventive technique to identify and repair such minor issues with the refractory lining before escalation. The use of this technique in the proper frequency may result in furnace life cycle extension.