Mechano-Electrochemical Behavior of Pyrite in Different Grinding Media

The mechanical electrochemishy equipment is different from conventional electrochemistry equipment, which can exert pressure to the surface of the electrode by adjusting die height of the lifting platform and change the pressure of electrode (see Fig. 8.1). Before the experiment, the electrode surface was polished, and the grinding media, electrolyte and reagent were added in order. 

2 Mechano-Electrochemical Behavior of Pyrite in Different Grinding Media 

Different flexibility distortion will be produced on the surface of material due to partial mechanical force, which induce the change of corrosion potential and material surface state. 

The variation of corrosion potential and out circuit current of pyrite electrode at static state with sphalerite as the opposite electrode at natural pH in the presence of xanthate is presented in Fig. 8.5. It is the variation of the electrode potential and the current of pyrite electrode under different grinding pressure with sphalerite as the grinding media at natural pH in the presence of xanthate. 

It can be seen from Fig. 8.5 that pyrite still exhibits the cathodic characteristic when sphalerite is used as the opposite electrode at static state. The corrosion potential of the pyrite electrode decreases at the beginning and is finally stabilized at about 140 mV. The pyrite electrode has not exhibited obvious cathode current. When sphalerite is used as the grinding media as seen from Fig. 8.6, the potential of pyrite electrode decreases with the increase of the mechanical pressure exerted on it and the grinding time. Pyrite exhibits cathodic characteristic, but the degree of cathode polarization is less than that in Fe grinding media. Corrosion potential of the pyrite electrode reaches to the lowest value about 145 mV at pressure of 800 g and 8 min. 

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