Mapping of Hydrophobic Interactions for Investigating the Floatability of Mineral Using Atomic Force Microscopy and Raman Spectroscopy

The novel method of measuring the floatability of individual mineral phases on an ore cross section is presented. Combining atomic force microscopy with Raman spectroscopy can make use of hydrophobic effects to evaluate the hydrophobization of surfaces, a crucial microprocess of flotation. This paper presents comparative results of classic microflotation experiments and the new method looking at pure mineral samples of magnetite and quartz using simple anionic and cationic collectors. The mapping capabilities and identification of mineral phases with Raman spectroscopy is presented for a silicate type or from southern Sweden containing the mineral eudialyte rich in heavy rare earth elements. We show theoretically and experimentally the different possibilities to determine hydrophobic effects using force spectroscopy and the colloidal probe technique with a hydrophobic colloid attached to the cantilever of an atomic force microscope. This novel concept shall not only be a plain research tool but should help to simplify the investigation of the right flotation reagent and thus optimize flotation processes.