Orebodies at Ok Tedi contain a number of different fluorine
bearing minerals. Some of these minerals report to concentrate
and are responsible for the presence of the penalty element,
fluorine, within the concentrate. Previous analytical work has
tended to examine geological samples for content, rather than
determine the metallurgical behaviour of the different
mineralogical species. This investigation utilised X-Ray
Diffraction combined with Scanning Electron Microscope /
Electron Microprobe to identify the fluorine bearing minerals in
flotation test products. Seven fluorine bearing minerals were identified, viz., talc,
phlogopite, amphibole (tremolite and actinolite), sphene, apatite,
biotite and clay. Talc was found exclusively in the skam ore type.
Phlogopite and amphiboles (tremolite and actinolite) were found
to occur in both skarn and porphyry ores, while sphene, apatite,
biotite and clay were found only in the porphyry ores. Of the
fluorine bearing minerals observed, only talc exhibited natural
hydrophobicity to any significant degree. Phlogopite and the
amphibole minerals were found to be hydrophillic, whilst the
remaining minerals occurred in insufficient quantities to determine
the flotation behaviour. Ok Tedi copper concentrate fluorine content prior to skarn ore
treatment in the mill (typically 350ppm) was previously identified
as deriving from phlogopite, while talc was believed to be the
source of intermittent high concentrate fluorine contents when
skarn ores were treated. This paper provides supporting evidence
for this belief, and reports the nature of fluorine bearing mineral
flotation behaviour.