Ultrafine particle flotation in a concept flotation cell combining turbulent mixing zone and deep froth fractionation with a special focus on the property vector of particles

Froth flotation faces increasing challenges in separating particles as those become finer and more complex, thus reducing the efficiency of the separation process. A lab flotation apparatus has been designed with the idea of combining the advantages of agitator-type froth flotation for high turbulences and column flotation with a deep froth zone for a fractionating effect enabling also to study the effect of different particle property vectors. A model system consisting of ultrafine (< 10 μm) glass particles with differing morphology (spheres vs. fragments) and wettability state (hydrophilic vs. moderately hydrophobic vs. strongly hydrophobic) as the floatable and magnetite as the non-floatable fraction was used for flotation to study how the separation process is influenced by the ultrafine property vectors of shape and wettability. Within this newly designed apparatus the froth depth was varied to investigate the fractionating effect and how the different particle fractions are affected by it. Furthermore, to evaluate the new apparatus, flotation tests had been carried out in a benchmark mechanical flotation cell under comparable conditions. Our findings contribute to ultrafine flotation techniques and especially our understanding of the complex effect of particle shape in combination with the other property vectors.