Up-scaling of froth flotation equipment

The up-scaling of flotation equipment has been investigated based on comparisons between laboratory, pilot and industrial scale flotation tests and a characterization study of large-scale industrial flotation cells in Boliden’s Aitik copper mine in Northern Sweden. The use of high volume flotation cells has nowadays become more and more common to deal with the production of high capacity, low-grade open pit mines, which are typically copper or gold mines. Implementation of large flotation cells in the mineral beneficiation process holds several financial benefits, but gives no guarantee of an equal or improved metallurgical performance. From a historical point of view, flotation plants have been designed based on the results of laboratory tests, multiplied with a time up-scaling factor at which recovery was expected to be above a certain value on the industrial scale. Due to the uniqueness of each ore, such an experience-based factor has often resulted into under- or overestimations of the total required cell volume. One of the main differences between lab and industrial flotation in this research is found to be the behaviour of fine particles (-45 μm), which are shown to have slower flotation kinetics and poor recovery on the industrial scale in comparison to the lab scale, but are also accompanied by a relatively high degree of gangue mineral entrainment in lab tests.