黄铁矿与毒砂氧化行为差异的电极过程动力学研究  

Electrode process kinetics of oxidation behavior difference between pyrite and arsenopyrite

作　　者：李新春 焦芬[1,2] 覃文庆[1,2] 崔艳芳[1,2] 李佳磊 LI Xinchun;JIAO Fen;QIN Wenqing;CUI Yanfang;LI Jialei(School of Minerals Processing&Bioengineering,Central South University,Changsha 410083,China;Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources,Central South University,Changsha 410083,China)

机构地区：[1]中南大学资源加工与生物工程学院,湖南长沙410083 [2]中南大学战略含钙矿物资源清洁高效利用湖南省重点实验室,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2023年第8期2965-2972,共8页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51904339,52074355,51974364);中南大学研究生科研创新项目(2021zzts0906)。

摘　　要：采用动电位扫描、循环伏安和恒电位阶跃等电化学测试方法研究黄铁矿与毒砂电极氧化过程,强化其浮迭分离效果,分析黄铁矿与毒砂动力学行为的差异性。研究结果表明:pH=11时,毒砂与黄铁矿的表面氧化产物中均有Fe(OH)_(3)和SO_(4)^(2-)等亲水物质生成,且黄铁矿的起始氧化电位要比毒砂的高,而对应的氧化峰电流密度却比毒砂的低,说明毒砂比黄铁矿更容易氧化,毒砂表面能够更快、更容易形成亲水性的表面。在试验特定的pH条件下,毒砂的腐蚀电位均低于黄铁矿的腐蚀电位,且在pH分别为4、6.86、9.18和11时,毒砂的氧化速率依次是黄铁矿的0.83、1.40、2.57和1.52倍,两者的氧化速率存在显著差异。pH=11时,黄铁矿的氧化动力学方程为η=0.248 logi_(t→0)+1.346,其中i_(0)=3.8μA/cm^(2),毒砂的氧化动力学方程为η=0.291 logi_(t→0)+1.515,其中i_(0)=6.18μA/cm^(2),测试结果与Tafel测试结果一致。The oxidation process of pyrite and arsenopyrite at the electrode was studied by means of potentiodynamic scanning,cyclic voltammetry and potentiostatic step method to enhance the flotation separation of arsenopyrite and pyrite.The different of kinetic behavior between pyrite and arsenopyrite was analyazed.The results show that when pH=11,hydrophilic substances such as Fe(OH)_(3)and SO_(4)^(2-)are formed in the surface oxidation products of arsenopyrite and pyrite.The initial oxidation potential of pyrite is higher than that of arsenopyrite,but the current density of the corresponding oxidation peak is lower than that of arsenopyrite,which shows that arsenopyrite is easier to oxidize than pyrite,and the surface of arsenopyrite can form hydrophilic surface more quickly and easily.The corrosion potential of arsenopyrite is lower than that of pyrite under the condition of pH.At pH 4,6.86,9.18 and 11,and the oxidation rates of arsenopyrite are 0.83,1.40,2.57,and 1.52 times of pyrite,respectively.When pH=11,the oxidation kinetic equation of pyrite isη=0.248 logi_(t→0)+1.346,i_(0)=3.8μA/cm^(2),the oxidation kinetic equation of arsenopyrite isη=0.291 logi_(t→0)+1.515,i_(0)=6.18μA/cm^(2),which is consistent with the results of Tafel.

关 键 词：黄铁矿 毒砂 电极过程 动力学 

分 类 号：TD952[矿业工程—选矿]