Calcium and magnesium ions in process water have been reported to have significant influence on froth stability and flotation recovery, however little research has been done to identify influential ions during the flotation of PGE containing ores. Thus the purpose of this study was to investigate the effect of typical electrolytes present in process water on the flotation of a Merensky ore. The ionic strength was kept constant at 0.0213 mol.dm(-3) for all electrolyte solution. Cation and anion effects were investigated and each electrolyte compared with the standard synthetic plant water. The results showed higher amounts of solids recovered for all sodium electrolytes whereas calcium and magnesium electrolytes resulted in similar solids recovery. NO3- ions resulted in significantly higher Cu and Ni grades than Cl- and SO42- ions. The results seem to suggest that the influence of ion type depends on its ability to enhance or retard gangue activation. (C) 2016 Elsevier Ltd. All rights reserved.