Physical, Chemical and Mineralogical Characterization of Fluorspar Flotation Tailings

Abstract

The beneficiation potential of fluorspar tailings to produce high grade haematite pellets was investigated. Detailed characterisation of the tailings was carried out, where physical, chemical, and mineralogical and liberation properties of the sample were determined, with the aim of selecting a suitable beneficiation technique. The XRF results showed that the major oxide component in the sample is Fe2O3 (71.2 wt.%) with main gangue being silica (16.8 wt.%), calcium oxide (3.8 wt.%) and remaining oxides at <1 wt.%. The Fe present in the fluorspar tails as per XRF results was 49.89%. The XRD results showed that the sample is predominantly hematite with moderate quartz and minor amounts of goethite, magnetite and fluorite. The QEMSCAN BMA results showed a subordinate presence of goethite (9.76%), magnetite (5.91%), fluorite (6.21%) and hematite (60.83%). The sample had a grind size of 80% passing 155 µm with Fe concentration increasing in the finer size range, with majority of the Fe-oxide occurring between 10-70 µm. The Fe-oxide mineral liberation characteristics results indicated that 81.11% of the grains are full liberated, while 16.17% are the middlings and 2.72% locked in gangue. Based on the results and a requirement to make high iron grade pellets, reverse flotation method was selected for concentrating Fe in the fluorspar tails.