2.3 Flotation Test ProcedureThe rougher flotation test on the GRG tailings was performed at natural pH, using potassium amyl xanthate (PAX) as the primary collector added in incremental dosages, Aero Maxgold (AMG900) as a promotor in the second stage to boost the gold recovery, dialkyl dithiophosphate 3418A (P- based sulphide collector) in the third stage, copper sulphate as an activator in the fourth stage, and finally methyl isobutyl carbinol (MIBC) as a frother. The flotation feed sample P80 was 74 µm. The detailed rougher flotation test procedure is presented in Appendix D.