Specific surface free energy distributions and floatabilities of minerals with physi- and chemisorbing collectors


Specific surface free energy distributions and floatabilities of minerals with physi- and chemisorbing collectors

Rudolph, M.; Chehreh Chelgani, S.; Hartmann, R.

Flotation separates particles with different wettability dispersed in water. The fundamental physical-chemical property therefore is the specific surface free energy of the mineral surface which together with the specific surface free energy of water causes wettability phenomena besides the surface morphology (e.g. roughness). Inverse Gas Chromatography (iGC) is a tool which enables determination of the specific surface free energy of powders. There are a few reports on the correlation of flotation response and surface free energy, however the crucial problem is that the floatability is determined in water and the surface free energy is evaluated in the dried powder phase. To determine the effect flotation chemicals have on the specific surface free energy of minerals it is important to investigate the preparation of the dried powder after conditioning with the chemicals in water.
In this paper different minerals (quartz, apatite and magnetite) and ionic collectors (anionic sodium oleate and cationic dodecyl ammonium acetate) with crucially different surfactant adsorption mechanisms are used to determine floatability (microflotation) and specific surface free energy distributions (iGC) with different steps of preparation, i.e. washing with mother liquid only or further with solvents with another polarity. The flotation response and the specific surface free energy are put in context and discussed. A proper presentation of the surface free energy components is presented giving a quantitative description of hydrophobicity. There will also be a short introduction to and discussion of the method of inverse Gas Chromatography as it is rather new in the field of mineral processing.

Keywords: inverse gas chromatography; flotation; surface free energy; wettability; hydrophobicity; particle-bubble intreractions; apatite; magnetite; quartz; collector; adsorption

  • Lecture (Conference)
    Conference in Minerals Engineering, 03.-04.02.2015, Lulea, Sweden

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Publ.-Id: 21571