硫化矿物浮选体系中外控电位电极与矿物颗粒间的电偶腐蚀作用及其浮选

Galvanic Corrosion between External Potential-control Electrode and Mineral in the Flotation System of Sulfide Minerals and Its Significance on Flotation

硫化矿物浮选电化学研究中,控制电位的方式有两种:氧化还原药剂调控和外加电场电位调控。在外控电位浮选体系中,由于外控电位电极与硫化矿物的腐蚀电位差异,电极与硫化矿物碰撞接触时形成电偶腐蚀。从腐蚀电化学理论出发,研究了电极与硫化矿物形成的电偶腐蚀对硫化矿物浮选过程的影响,指出所形成的电偶腐蚀对硫化矿物浮选过程的影响与电极极性、电极材料、矿物的浮选特征等有关。当浮选过程需要发生硫化矿物颗粒表面的氧化时,工作电极应为阳极,电极材料应有较高的腐蚀电位;当浮选过程需要发生硫化矿物颗粒表面的还原反应时,工作电极应为阴极,电极材料应有较矿物颗粒低的腐蚀电位;要消除电极与矿物颗粒之间的电偶腐蚀作用,外控电位电极材料的腐蚀电位与目的矿物颗粒的腐蚀电位应相等或相近。研究结果可为实现硫化矿物浮选过程中外控电位方式、电极材料和电极极性的选择提供依据。

In the system of flotation by external potential-control, due to the difference of corrosion potential between external potential-control electrode and sulfide minerals, when electrode collides with sul-fide minerals, it can generate galvanic corrosion. In the process of flotation by external potential-control, based on the corrosion electrochemistry, the influence of galvanic corrosion induced by electrode and sulfide minerals on the flotation of sulfide minerals has been investigated. Influence of galvanic corrosion on the flotation of sulfide minerals was relevant to electrode polarity, electrode material and flotation character of mineral. In the process of flotation, when the oxidation of mineral surface is needed, working electrode should be anode and the electrode material should have high corrosion potential; when the reduction of mineral surface is needed, working electrode should be cathode and the corrosion potential of electrode material should be lower than that of minerals. In order to eliminate the influence of galvanic corrosion induced by electrode and minerals on flotation, the corrosion potential of external potential-control electrode must be equal or close to the corrosion potential of aimed mineral. The results of this research show great importance on the selection of electrode material, selection of electrode polarity and successful flotation in the process of flotation by external potential-control.