磨矿和浮选过程中黄铁矿电化学行为的研究进展

Research progress in the electrochemical behavior of pyrite during grinding and flotation

综述了黄铁矿在选矿过程中有关的电化学行为及工作机理,重点讨论了黄铁矿结构特性、溶液中氧化、金属离子作用和抑制剂对黄铁矿电化学行为的影响;此外,还讨论了磨矿过程中电偶相互作用、研磨介质形状、介质材料和研磨气氛对研磨中黄铁矿电化学行为的影响.其中黄铁矿晶体结构的不同对黄铁矿表面的氧化具有较大影响,从而间接的影响黄铁矿的可浮性,半导体性质对黄铁矿的导电率具有显著的影响;同时适度的氧化有利于黄铁矿的无捕收剂浮选,而强烈的还原电位或氧化电位会抑制黄铁矿的浮选;电位的增加,对铜活化黄铁矿有不利影响,主要原因是电位增加导致活化Cu+的浓度降低,同时黄铁矿表面被铁氧化物覆盖阻碍了铜离子的吸附.抑制剂的加入可以直接参与捕收剂与黄铁矿之间的氧化还原反应,从而抑制黄铁矿的浮选;同时磨矿介质及气氛条件的不同也会影响黄铁矿电化学行为.

Metal sulfides are highly desirable owing to their semiconductor properties promoting electrochemical reactions for sulfide flotation.As the most common sulfide mineral,pyrite is found in coal and can contain a small amount of gold.The potential of electrochemical reactions for the beneficiation of pyrite makes it necessary to study its electrochemical behavior.The present work focuses on the electrochemical behavior and working mechanisms of pyrite in mineral processing.The effects of the structural characteristics of pyrite,oxidation in solution,the presence of metal ions,and inhibitors on the electrochemical behavior of pyrite were discussed emphatically.The effects of galvanic interaction and grinding medium shape,material,and atmosphere on the electrochemistry of pyrite in grinding were also discussed.It has been shown that the different crystal structures and semiconductor properties of pyrite can greatly influence the oxidation of its surface,which indirectly affects its floatability.Moreover,moderate oxidation conditions are beneficial to the collector-free flotation of pyrite,whereas strong reduction or oxidation potentials inhibit its flotation.It has also been shown that increase in potential and iron oxide on the pyrite surface lead to the decrease in the concentration of copper(Cu+)ions,thereby adversely affecting the activation of pyrite by copper.Furthermore,inhibitors can directly participate in the redox reaction between the collector and pyrite,thus inhibiting the flotation of pyrite.Different grinding media and atmosphere conditions also affect the electrochemical behavior of pyrite.