The efficiency of grinding experiments is an important issue for many industries. In this paper, a central composite design-based methodology was proposed to investigate the four design factors that affect the particle sizes. The four design factors were specified as mill speed (% of N-c ), ball filling ratio (f(c) ), powder filling ratio (j(b) ) and grinding time (min). Another important issue was how to obtain an optimum operating condition for four design factors. For this particular purpose, a novel dual response optimization model was proposed using the particle sizes (d (10), d (50), and d (90)) and the span value concept. This proposed approach was compared to the desirability function-based optimization concept. The verification study of the experiment was also carried out. The results of the grinding experiment runs showed that the optimum operating conditions were mill speed 73.495% of N-c , ball filling ratio 0.354, powder filling ratio 0.157, and grinding time 70 min. In addition, d (10), d (50), and d (90) were found 3.31 mu m, 12 mu m, and 45.6 mu m, respectively. The span value was also found at 3.52.