Desliming ultra-fine iron ore in the REFLUX™ graviton

The desliming and beneficiation of ultrafine iron ore particles, ranging from 0 – 100 µm in size, was investigated using the centrifugal system known as the REFLUX™ Graviton. This system subjects REFLUX™ Classifier modules, formed through 3D printing, to high G-forces creating a powerful hydrodynamic advantage. Processing ultrafine particles generally involves an initial desliming stage. The difficulty and costs involved in downstream processing of the overflow of this step typically leads to discarding to tailings, incurring a loss of valuable iron ore. As ore deposits deplete, improving the recovery of these ultrafines becomes increasingly necessary. The feed used for this investigation represents a waste stream in a processing plant that would usually be sent to tailings or require a significant desliming stage before further processing, having a grade of 55 wt.% Fe and Sauter mean size of 2 µm. Here, the REFLUX™ Graviton offers an alternative approach in both desliming and beneficiation. In addition to efficiently separating the material at a particle diameter of 15 µm, the concentrated product had a grade of over 63 wt.% Fe. This paper studies the effects of feed flowrates and fluidisation rates on the separation as well as the concentrations of iron and phosphorous in each stream.