摘要
通过加压氧化和电化学氧化方法研究了黄铜矿在硫酸溶液中氧化浸出的反应机制。采用金相显微镜、扫描电镜、X射线衍射仪和拉曼光谱对黄铜矿表面氧化产物的形貌和化学组成进行了分析。加压氧化试验结果表明:在pH=3的硫酸溶液中,黄铜矿表面发生钝化,钝化层由Fe2O3、FeOOH及贫铁硫化物(CuFe1-xS2或CuS2)组成。当浸出液pH=0~1时,铁的氧化物溶解,铜蓝(CuS)和单质硫(S0)成为新的钝化层。电化学氧化试验结果表明:黄铜矿在酸性介质中的氧化可以分为3个阶段:当阳极极化电位低于0.75V(vs.SCE)时,黄铜矿表面生成了贫铁硫化物,对其进一步氧化起钝化作用;当电位在0.8~1.0V范围时,贫铁硫化物被氧化成铜蓝和单质硫,组成新的钝化层;当电位高于1.05V时,硫元素被氧化成+4或+6价的氧化态进入酸性介质中。
Mechanism of oxidation leaching of chalcopyrite in sulfuric acid solution was investigated by pressurized oxidation and electrochemical oxidation methods.The morphology and chemical composition of surface oxidation products of chalcopyrite were examined by metallographic microscope,scanning electron microscopy,X-ray diffractometer and Raman spectroscopy.The results of pressurized oxidation test showed that in sulfuric acid solution with pH=3,the surface of the chalcopyrite was passivated,and the passivation layer consisted of Fe2O3,FeOOH and iron-depleted sulfides(CuFe1-x S2/CuS2).When the pH value of leaching solution was 0 to 1,iron oxide dissolved and covellite(CuS)and elemental sulfur(S0)became the new passivation layer.The results of electrochemical oxidation test showed that the oxidation of chalcopyrite in acidic medium could be divided into three stages:when the anodic polarized potential was lower than 0.75 V(vs.SCE),the iron-depleted sulfides formed on the surface of chalcopyrite,which passivated further oxidation of the chalcopyrite;when the anodic polarized potential was in the range of 0.8 V to 1.0 V,the iron-depleted sulfides were oxidized into covellite and elemental sulfur,forming a new passivation layer;when the anodic potential was above 1.05 V,the sulfur element was oxidized into an oxidation state of+4 or+6 and entered into the acidic medium.
作者
郑永飞
华晓鸣
许茜
鲁雄刚
程红伟
邹星礼
ZHENG Yongfei;HUA Xiaoming;XU Qian;LU Xionggang;CHENG Hongwei;ZOU Xingli(State Key Laboratory of Advanced Special Steel,Shanghai 200072,China;School of Materials Science and Engineering,Northeastern University,Shenyang Liaoning 110004,China;Shanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai 200072,China;School of Materials Science and Engineering,Shanghai University,Shanghai 200072,China)
出处
《上海金属》
CAS
北大核心
2019年第3期81-88,共8页
Shanghai Metals
基金
国家973重点基础研究发展计划(No.2014CB643405)
关键词
黄铜矿
加压酸浸
电化学
钝化
氧化过程
chalcopyrite
pressure leaching
electrochemistry
passivation
oxidation process
