Pyrochlore surface oxidation in relation to matrix Fe composition: A study by X-ray photoelectron spectroscopy

• XPS evaluated the relationship between pyrochlore composition and surface oxidation.
• Results show a greater degree of oxidation corresponds to higher matrix Fe content.
• Preferential surface oxidation corresponds with reduced collector loading.
• A relationship between pyrochlore composition and recovery is established.

The flotation recovery of pyrochlore from the Saint-Honore Carbonatite ore has been related to the variability in the mineral matrix Fe content; high Fe pyrochlore grains consistently report to the tails. Previous research has tentatively suggested that surface oxidation of high Fe pyrochlore grains may be driving partitioning of the pyrochlore grains to the tails. X-ray photoelectron spectroscopy (XPS) was used to examine the relationship between matrix Fe content and surface oxidation in high Fe pyrochlore grains and high Fe zoned regions in pyrochlore grains from the Carbonatite ore. XPS analyses of pyrochlore grains showed that a greater proportion of surface oxidation species corresponded to the zones with high matrix Fe content. The XPS data along with previously presented Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS) data demonstrates a relationship between matrix Fe content and collector attachment. The Fe rich pyrochlore grains or zones show a higher degree of oxidation relative to the Fe poor grains or zones. The data reveal that collector attachment favors low Fe grains or zones, likely in response to a lower degree of surface oxidation.