碳酸钠对毒砂氧化机理影响的电化学研究

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．

THE ELECTROCHEMICAL INVESTIGATION OF Na 2CO 3 EFFECT ON THE OXIDATION MECHANISM OF ARSENOPYRITE

Na 2CO 3 can selectively activate pyrite and effectively depreses arsenopyrite during pyrite floatation. The further investigation on the oxidation mechanism of arsenopyrite in the presence of Na 2CO 3 was carried out by using electrochemical techniques. From the results, it is demostrated that Na 2CO 3 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.