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

The coverage of potassium isobutyl xanthate (IBX) and sodium diisobutyl dit hiophosphinate (DBPhos) adsorbed on the surface of galena has been investig ated by Time of Flight Secondary ion Mass Spectrometry (TOF-SIMS). Differen ces in surface concentrations and distributions between particles and acros s individual particle surfaces were sought comparing flotation concentrate and tail samples. This study has shown that a large difference is found in collector adsorpti on for both IBX and DBPhos between different faces of galena particles. The amount of collector adsorbed on galena particles of different sizes was st atistically inseparable. However, a large variation in collector concentrat ion 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 f or each particle. Differences between collector distributions on concentrat e and tail samples can be statistically separated. TOF-SIMS data also produ ced various hydrophilic and hydrophobic indices derived from the selected p airs 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 hyd roxides were found to be statistically greater on tailings than on the conc entrate 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.