Multidimensional Flotation Separation of Ultrafine Particles
Froth flotation is a well-established and efficient ore processing technique for separating ore from gangue minerals within sizes ranging from about 10 to 200 µm. The process is based on the selective hydrophobisation of ore minerals in a pulp and the attachment of these particles onto gas bubbles, which are then removed in a froth. That is why particle surface properties as well as other particle properties such as particle size and morphology are fundamental separation features in froth flotation.
One of the greatest challenges especially in the flotation of ultrafine particles (< 10 µm), is the so-called entrainment, where undesired ultrafine gangue particles are mechanically carried into the froth and hence reduce the quality of the process product.
Thus MultiDimFlot, a project currently carried out in the Processing Department has the goal to develop a new technology aiming for the multidimensional separation of ultrafine particles by using a combination of intensive mechanical flotation in a rotor-stator cell and fractionation in a deep froth.
By studying microprocesses that occur in the pulp and in the froth phase during flotation, the Processing Department wants to gain a deeper understanding of the behaviour of ultrafines in order to create new efficient and sustainable processes.
In the first funding period, a well-defined and characterised particle system is used to parameterize the system. The dominant separating features are the particle shape and their surface energy, which are studied via X-ray microtomography and inverse gas chromatography.
Multidimensional Flotation Separation of Ultrafine Particles (MultiDimFlot) is part of the priority program SPP 2045 MehrDimPart funded by the Deutsche Forschungsgemeinschaft and is coordinated by the TU Bergakademie Freiberg. The project duration is 2017 to 2020.