Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

Even though froth flotation is by far the most important fine particle separation process in mineral processing and recycling for a variety materials, there are still fundamental questions on its working principles.
Lately, we found that detachment forces of hydrophobic AFM colloidal probes from hydrophobized surfaces observed in aqueous conditions and supported by contact angle measures, visualization of adsorption layers and microflotation studies, is not reflected in existing detachment models. The additional observation that collectors of oily type in sulfide flotation and surfactant type in oxide mineral flotation adsorb in a heterogeneous patchy manor let us to extent existing detachment models We present a modelling approach for adhesion forces caused by gas-capillary interactions on surfaces with a macroscopic contact angle below 90°. In addition we show how both collector layers as well as surface gas can turn van der Waals interactions attractive with no need of an additional hydrophobic interaction.