Abstarct: Abbas Abad copper ore is in both oxide and sulphide forms and their simultaneous flotation does not have suitable efficiency due to different behavior between oxide and sulphide minerals. Therefore, mechanochemical sulfidization process was used as a new method to sulfidize the oxide copper in the grinding stage. In this research, the influence of adding sulfur into ball mill as mechanochemical sulfidization agent and the role of reductive additives including magnesium nitrate, iron nitrate (III) and aluminum chloride salts as well as iron and magnesium mextal powders in different concentrations were investigated on the copper flotation and the optimal values were determined. The results indicated to obtain the suitable d80 (90 microns), the optimum grinding time is 22 minutes. The addition of sulfur with 0.5% of feed weight into ball mill had the highest separation efficiency and copper recovery (75.76%) in the optimum time of grinding. Also, investigations showed that baxsed on the feed weight percentage, 0.2% magnesium nitrate, 0.5% iron nitrate (III), 0.5% aluminum chloride and 0.2% magnesium mextal powder had the best performance of flotation compared to other values. In general, 0.2% magnesium nitrate compounded with 0.5% sulfur had the most separation efficiency (62%) and the combination of 0.5% iron nitrate (III) with 0.5% sulfur had the highest copper recovery (83.23%). After determining the desirable condition of mechanochemical sulfidization, response surface statistical model (RSM) was applied to optimize and evaluate the important factors affecting the flotation such as pH, agitation speed and the consumption amount of chemicals including collector, frother and depressant. The results demonstrated that copper recovery depended strongly on the interactive effects between frother and pulp agitation speed, pH and agitation speed, and collector and frother. Also, the maximum copper recovery (92.75%) was obtained at the pH of 10, agitation speed of 1000 rpm, collector amount of 70 g/ton, sodium silicate value of 90 g/ton and frother amount of 7 g/ton.