Corrosive Electrochemistry

Abstract The flotation mechanism is discussed in the terms of corrosive electrochemistry in this chapter. In corrosion the disolution of minerals is called self-corrosion. And the reaction between reagents and minerals is treated as inhibition of corrosion. The stronger the ability of inhibiting the corrosion of minerals, the stronger the reagents react with minerals. The two major tools implied in the research of electrochemical corrosion are polarization curves and EIS (electrochemistry impedance spectrum). With these tools, pyrite, galena and sphalerite are discussed under different conditions respectively, including interactions between collector with them and the difference of oxidation of minerals in NaOH solution and in lime. And the results obtained from this research are in accordance with those from other conventional research. With this research some new information can be obtained while it is impossible for other methods. 

Keywords corrosive electrochemistry corrosive potential corrosion inhibition polarization curves Electrochemistry Impedance Spectrum 

As is known to all, the flotation mechanism of sulphide minerals can be explained based on electrochemistry because sulphide minerals have the semiconductor character and a series of electrochemistry reaction occurring in solution. After these reactions, the surface of sulphide minerals changes and forms a new phase. We called it as self-corrosion of sulphide minerals. As before, the essence of the reaction between the collector and the minerals is the formation of the hydrophobic entity on the mineral surface, and then minerals can be floated. We can find that the reaction between the collector and the minerals is similar to the depression on mineral self-corrosion. In the corrosion, we called this effect as inhibition, and this kind of reagent is an inhibiting reagent. There are many studies on corrosion, especially its research method and theory. Thus, we can get some new information on the mechanism of sulphide flotation from corrosive electrochemistry. 

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Shimamura, K., Miura, K. Kawashima, A., Asami, K. and Hashimoto, K., Proc. Symp. on Corrosion, Electrochemistry and Catalysis of Metallic Glasses, (Diegle, R. B. and Hashimoto, K., eds.), the Electrochemical Society, Pennington, 232 (1980)... 

The electrochemical resistance is smaller in the absence of DDTC, but increases four times in presence of DDTC. So the adsorption of DDTC on jamesonite results in reducing the reaction rate of the corrosive electrochemistry in open circuit potential. 

Chapter 7 Corrosive Electrochemistry of Oxidation-Reduction of Sulphide Minerals... 

Corrosive Electrochemistry on Surface Redox Reaction of Pyrite under Different Conditions... 

Corrosive Electrochemistry Study on Interactions between Collector and Pyrite... 

Table 7.2 Corrosive electrochemistry parameters of pyrite at different xanthate concentration...

The corrosive electrochemistry parameters are listed in Table 7.4. From Fig. 7.30 and Table 7.4, it can be seen that, after adding xanthate 5x 10" mol/L, the corrosive potential of galena electrode decreases from -48 to -94 mV, the corrosive current of the galena eleetrode decreases from 3.45 to 0.99 pA/cm, the polarization resistance increases to 18.7 kG and the inhibiting eorrosive efficiency increases to 28.34. Figure 7.31 shows that the EIS of galena electrode appears to have single capacitive reactance loop characteristic and the radius of the capacitive reactance loop increases with the increase of collector concentration. 

Table 7.4 Corrosive electrochemistry parameters of galena electrode in xanthate solution with different concentration...

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