Electrochemical corrosion of steel balls in wet grinding

Rest potentials for the steel ball electrode and the pyrite electrode as well as the combination potentials and the galvanic currents developed in the pyrite-steel ball couple were measured. The data demonstrate that the gal-vanic couples are going to form between the pyrite particles and the steel balls when they contact with each other.The initial combination potential and the initial galvanic current of the pyrite-ball couple while bubbling with oxygen are greater than those in aeration of air. The combination potential and the galvanic current decrease more quickly with time while bubbling with oxygen than they do in aeration of air. In an experiment of simulating wear differ-ences, a galvanic current, which is smaller than that developed in the pyriteball couple, exists between two differ-ent ball electrodes in wear degree on the surface of them. Under different grinding time conditions, the equivalent corrosion current density calculated from marked ball wear data by applying Faraday''s law correlates well with those estimated from polarization curves of pyrite and ball electrodes, and the former is always greater than the latter.