In-situ electrochemical study on the eff ects of Fe(Ⅲ)on kinetics of pyrite acidic pressure oxidation  

作　　者：Yu Zhang Can Cui Sen Lin Heping Li Lian Yang Yadian Xie Hailiang Hu Lingyun Zhou Huanjiang Wang Chunyan Li 

机构地区：[1]School of Chemical Engineering,Guizhou Minzu University,Guiyang 550025,China [2]Key Laboratory of High-Temperature and High-Pressure Study of the Earth’s Interior,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China

出　　处：《Acta Geochimica》2024年第4期814-825,共12页地球化学学报（英文）

基　　金：supported by the Science and Technology Foundation of Guizhou Province,China(No.[2020]1Y163);the National Natural Science Foundation of China(No.41827802).

摘　　要：Fe(Ⅲ)has been proved to be a more eff ective oxidant than dissolved oxygen at ambient temperature,however,the role of Fe(Ⅲ)in pyrite acidic pressure oxidation was rarely discussed so far.In this paper,in-situ electrochemical investigation was performed using a flow-through autoclave system in acidic pressure oxidation environment.The results illustrated that increasing Fe(Ⅲ)concentrations led to raising in redox potential of the solution,and decreased passivation of pyrite caused by deposition of elemental sulfur.Reduction of Fe(Ⅲ)at pyrite surface was a fast reaction with low activation energy,it was only slightly promoted by rising temperatures.While,the oxidation rate of pyrite at all investigated Fe(Ⅲ)concentrations increased obviously with rising temperatures,the anodic reaction was the rate-limiting step in the overall reaction.Activation energy of pyrite oxidation decreased from 47.74 to 28.79 kJ/mol when Fe(Ⅲ)concentration was increased from 0.05 to 0.50 g/L,showing that the reaction kinetics were limited by the rate of electrochemical reaction at low Fe(Ⅲ)concentrations,while,it gradually turned to be diffusion control with increasing Fe(Ⅲ)concentrations.

关 键 词：PYRITE Pressure oxidation Fe(Ⅲ) In-situ electrochemistry Hydrothermal experiment 

分 类 号：TF831[冶金工程—有色金属冶金]