表生环境下闪锌矿氧化反应模拟实验  

A simulated experimental study of oxidative reaction of sphalerite in hypergene environment

作　　者：潘自平[1,2] 叶霖[2] 谯文浪 刘铁庚[2] 

机构地区：[1]贵州财经大学资源与环境管理学院,贵州贵阳550004 [2]中国科学院地球化学研究所,矿床地球化学开放研究实验室,贵州贵阳550002 [3]贵州省地质调查院,贵州贵阳550004

出　　处：《岩石矿物学杂志》2013年第6期985-994,共10页Acta Petrologica et Mineralogica

基　　金：国家自然科学基金项目(40373021);1:25万贵阳;独山区调项目(黔国土资发2008-114);贵州省优秀科技教育人才省长专项资金项目(黔省专合字(2012)27号)

摘　　要：采用混合流反应器装置,进行了表生环境条件下闪锌矿氧化动力学模拟实验研究,选择Fe3+和O2为氧化剂,实验条件为:温度20～55℃,pH=1.0～7.8、氧化剂Fe3+浓度1.0×10-5～1.0×10-2mol/L,氧气流量0.5 L/min。实验结果表明,在Fe3+为氧化剂时,闪锌矿氧化速率随着Fe3+浓度的增加、温度升高、pH值降低而增加,且氧化过程中Zn和Cd的释放速率大致相同,其反应的活化能分别为Ea(Zn)41.75 kJ/mol或Ea(Cd)42.51 kJ/mol,表明闪锌矿氧化速率主要受矿物表面反应控制;而以氧气作为氧化剂时,随着pH值的变化闪锌矿的氧化机理发生变化,在pH值小于5.95范围内,闪锌矿氧化速率随着pH值的增加而降低,进入碱性范围后,随着pH值增加,闪锌矿氧化速率反而增加。对实验数据进行双对数处理并建立了闪锌矿的氧化速率公式。The sphalerite oxidative kinetics in hypergene condition was simulated and studied by means of a mixed flow reactor in the pH range of 1.0～7.8,dissolution temperature from 20℃ to 55℃,ferric ion concentration from 1.0 × 10-5 to 1.0 × 10-2 mol/L,and O2 flux 0.5 L/min,with ferric ion and O2 as oxidants.The results indicate that,with ferric ion as the oxidant,the oxidation rate of sphalerite increases with increasing ferric ion concentration,temperature and decreasing pH value,and that,under the conditions studied,the dissolution rates of Zn and Cd are approximately similar to each other,with the activation energy being 41.75 kJ/mol and 42.51 kJ/mol,respectively,which suggests the oxidation rate of sphalerite is controlled by mineral surface chemical reaction.However,with O2 as the oxidant,the oxidation mechanism of sphalerite varies with the pH value,and its oxidation rate decreases with increasing pH value in the pH range lower than 5.95,whereas the increase of pH value results in a increase of the oxidation rate in the range of pH value greater than 7.The oxidation rate of sphalerite based on double logarithmic dealing with data can be set up.

关 键 词：闪锌矿 氧化反应实验 混合流反应器 表生环境条件 矿山环境污染 

分 类 号：P578.23[天文地球—矿物学]