碳酸钠对毒砂氧化机理影响的电化学研究

来源期刊：中南大学学报(自然科学版)1997年第2期

论文作者：杨家红 陈万雄 赵中伟

文章页码：43 - 46

关键词：表面氧化； 毒砂； 电化学； Na₂CO₃作用； 旋转电极

Key words：surface oxidation； arsenopyrite； electrochemistry； Na₂CO₃ action； rotating disc electrode

摘    要：Na₂CO₃在黄铁矿和毒砂浮选分离 过程中能显著地活化黄铁矿和有效地抑制毒砂．作者应用电化学测试方法对毒砂在Na₂CO₃溶液中的氧化机理进行了深入研究．结果表明，Na₂CO₃改变了 毒砂的氧化机理，使其氧化过程由活化能高的混合控制转变为活化能较低的扩散控制，活化能降低了11．402KJ/moL，加快了氧化速度，并形成不易被还原的致密氧化产物，从而使毒砂表面强烈亲水而被抑制，为有效地实现硫砷分离创造了条件．

Abstract: Na₂CO₃ can selectively activate pyrite and effectively depreses arsenopyrite during pyrite floatation. The further investigation on the oxidation mechanism of arsenopyrite in the presence of Na₂CO₃ was carried out by using electrochemical techniques. From the results, it is demostrated that Na₂CO₃ can change the oxidation mechanisms of arsenopyrite and make the reaction change from mixed-control seep with higher activation energy to aneco-diffusion control one with less activation energy, decreasing the activation energy from 24 390 kJ/mol to 12 978 kJ/mol. As a result, its oxidation rate is accelated and compact oxidation products are difficult to be reduced and strongly bonded to the surface so that arsenopyrite shows strongly hydrophilic characteristic and is depressed. This make it possible to separate pyrite from arsenopyrite effectively through floatation.