Abstarct: Ball mills are common grinding equipment in the mineral processing industries, which their balls are damageable components. The ball wear is resulted from three mechanisms of impact, abrasion and corrosion, in which corrosion mechanism due to chemical-electrochemical nature has been investigated less. On the other hand, corrosion is observed more in grinding of sulphide ores, because most sulfide minerals are semiconductors. The aims of this research work were focused on studying of the electrochemical behavior of ball mills, evaluating of the factors affecting the balls corrosion rate and modeling of the steel balls corrosion to find an optimum condition for minimizing the corrosion rate. In order to obtain goals of thesis, a specialized electrochemical grinding system including, ball mill and electrochemical equipment (potentiostat/galvanostat accompanied by a three-electrode system) in Sarcheshmeh copper mine was designed and constructed. Study of electrochemical behavior of ball mill showed that the ball type, water chemistry, aeration conditions into the mill, ore mineralogy, increase of pH and solid percentage changed considerably the electrochemical characterizations and led to a reducing environment. Consequently, it caused that the galvanic couple among minerals and balls, oxidized iron species inside the mill and copper recovery in flotation process accordingly reduced. It also was estimated that 73.51% of the corrosion products, was generated from the steel balls oxidation. Evaluation of factors affecting the corrosive wear indicated that nitrogenization the mill, using distilled water and high carbon chromium steel balls, increase of pulp pH and solid content strongly reduced balls corrosion rate. It was also observed that corrosion rate enhanced with reducing throughout and increasing grinding time and mill speed. In addition, the ball charge weight enhanced, up to certain value, the rate of corrosion increased and thereafter decreased. Meanwhile, it was determined that corrosion mechanism was formed 27.68% of balls total wear. The modeling of balls corrosions implied minimum corrosion rate of low alloy steel ball (78.38 mpy) obtained at pulp pH=9.8, solid percentage, 40, throughout, 720g, ball charge weight, 9.25kg, rotation speed, 70rpm and grinding time, 10 minutes, while minimum corrosion rate for high carbon chromium steel (40.76 mpy) obtained at pulp pH=10, solid percentage, 40, throughout, 700g, ball charge weight, 8kg, rotation speed, 70rpm and grinding time, 10.5 minutes. Finally, mathematical models with coefficients of correlation upper than 0.9 were suggested.