Statistical comparison of surface species in flotation concentrates and tails from TOF-SIMS evidence

The coverage of potassium isobutyl xanthate (IBX) and sodium diisobutyl dithiophosphinate (DBPhos) adsorbed on the surface of galena has been investigated by Time of Flight Secondary ion Mass Spectrometry (TOF-SIMS). Differences in surface concentrations and distributions between particles and across individual particle surfaces were sought comparing flotation concentrate and tail samples. This study has shown that a large difference is found in collector adsorption for both IBX and DBPhos between different faces of galena particles. The amount of collector adsorbed on galena particles of different sizes was statistically inseparable. However, a large variation in collector concentration on particles of the same size was observed Statistical analysis of DBPhos on galena particles in the first concentrate and tail indicated that TOF-SIMS can be used to quantitatively investigate the flotation response of galena based on hydrophobic/hydrophilic ratios for each particle. Differences between collector distributions on concentrate and tail samples can be statistically separated. TOF-SIMS data also produced various hydrophilic and hydrophobic indices derived from the selected pairs of related spectral measures: Ca+/Pb+, Al+/Pb+ PbOH+/Pb+, SO3-/S-2(-); DBPhos(-)/SO3-. Linear regression and mean analyses were used to estimate these indices; the results correlated closely with the flotation response. Hydrophilic species concentrations such as calcium, aluminium and metal hydroxides were found to be statistically greater on tailings than on the concentrate particle surfaces. The method suggests that it will be possible to assess conditioning of sulphide surfaces for optimum selectivity. (C) 2000 Elsevier Science Ltd. All rights reserved.