Optimizing Rougher Flotation Parameters of the Esfordi Phosphate Ore

The performance of rougher flotation of the Esfordi phosphate ore was studied by a series of batch flotation tests. A central composite experimental design was employed to evaluate the effects of six main parameters on the recovery of phosphate and iron into the concentrate. A response surface model was fitted to results for the recovery of P2O5, which showed that the linear effects of conditioning time and co-collector, and the quadratic effects of conditioning time and solid concentration, were statistically significant. The significant parameters for the recovery of iron were the linear effects of pH, solid concentration, collector and conditioning time, the interaction effect of solid concentration and depressant, and the quadratic effect of pH. Using Design Expert software, it was shown that within the range of parameters investigated, a P2O5 recovery of 90.4% with a Fe recovery of 6.6%, could be obtained. The optimized values of the parameters were verified on feed samples and compared with the actual regime in the process plant.