Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

1 Publication
Applications of the atomic force microscope in flotation research
Babel, B.; Rudolph, M.ORC
This abstract gives an overview of the applications of the Atomic Force Microscope (AFM) in flotation research. The AFM, which has a broad application in different disciplines, is a versatile tool to measure surface properties and particle-particle interactions. In the field of mineral processing the AFM can be utilized to gather information of mineral surfaces such as the surface roughness or particle-particle interactions related to separation processes like magnetic separation, triboelectric separation and flotation. In the context of flotation it is possible to measure the hydrophobic interaction between a colloidal probe (CP-AFM) and the mineral surface. One drawback of this technique is the missing link between the hydrophobicity and the chemical composition of the mineral surface, respectively the adsorbed layers. This limitation can be exceeded by the combined utilization of the AFM and Raman Spectroscopy named Tip-Enhanced Raman Spectroscopy (TERS). This surface sensitive technique enables the chemical analysis of thin films with nanometer resolution by the utilization of a plasmonic effect that occurs at the surfaces of noble metal nanoparticles. The aim is the detection of adsorbed flotation reagents on mineral surfaces. The combination of TERS and CP-AFM measurements enables the investigation of the adsorption of flotation reagents on mineral surfaces and their effect on hydrophobicity.

As outlined the application of the AFM in mineral processing can give a deeper understanding of occurring micro processes and thereby a better physical and chemical description of macro processes. Especially TERS offers a better understanding of the adsorption of flotation reagents.

The paper presents fundamental investigations of CP-AFM and TERS on actual mineral specimens (quartz, cassiterite, apatite, calcite, scheelite) which are prepared to achieve a surface roughness of less than 10 nm. The impact of collector and depressant adsorption on the measurement, i.e. hydrophobic interactions with CP-AFM and vibrational spectroscopy with TERS is shown.
Keywords: atomic force microscope, tip-enhanced Raman spectroscopy, flotation
  • Poster
    XXVIII International Mineral Processing Congress, 11.-15.09.2016, Québec city, Canada

Publ.-Id: 24909 - Permalink