氧化亚铁硫杆菌抑制黄铁矿可浮性作用机理

Suppression Mechanism of Thiobacillus Ferrooxidans as Biosorbate for Reducing Floatability of Pyrite

通过对氧化亚铁硫杆菌吸附前后黄铁矿Zeta电位和表面接触角的测定,研究了其表面电性和润湿性变化,探讨了氧化亚铁硫杆菌抑制黄铁矿可浮性的作用机理.结果表明,氧化亚铁硫杆菌作用后,黄铁矿的表面电性发生明显变化,等电点pH值降低,表面润湿性变化不明显;氧化亚铁硫杆菌吸附对黄铁矿可浮性的抑制作用不是来源于增强黄铁矿表面的亲水性,而是由于减少了浮选捕收剂在黄铁矿表面的吸附,静电作用和空间位阻效应是导致黄铁矿可浮性受到抑制的重要原因.

Zeta potential and surface contact angle of pyrite were measured before and after adsorbing Thiobacillus ferrooxidans onto pyrite surface to examine its change in electrical properties and wettability, and the suppression mechanism of Thiobacillus ferroo.ridans as biosorbate for reducing the floatability of pyrite during froth floatation was discussed. The results showed that after interacting with Thiobacillus ferrooxixdans the surface electrical properties of pyrite change obviously to result in the reduction of pH value at ira-electric point, but its surface wettability varies slightly. The suppression effect of Thiobacillus ferrooxidans as biosorbate onto pyrite surface does not result from increasing its surface hydrophilicity but from weakening the attachment of collector to pyrite particles during froth floatation. Electrostatic interaction and sterie hindrance are the main causes of the suppression of pyrite floatability.