The rate processes of oxidative dearsenication of niccolite ore in microwave oven and in conventional furnace were measured with thermogravimetric technique.The results show that the dearsenication rate of niccolite o...The rate processes of oxidative dearsenication of niccolite ore in microwave oven and in conventional furnace were measured with thermogravimetric technique.The results show that the dearsenication rate of niccolite ore with microwave heating becomes faster than that with conventional heating. Under the conditions of an approximate linear heating and a definite air flow,the oxidative dearsenication process of niccolite ore is mainly controlled by interfacial chemical reaction.The ex- perimental data are in agreement with the kinetic model of linear heating as follows: In{[1-(1-α)^(1/3)]/T}= In (PAM)/(r_oρφE)(1-(RT)/E)-E/(RT) Thus the apparent activation energies of oxidative dearsenication of the niccolite ore containing differ- ent additions have been obtained from the model.展开更多
Avoiding the formation of a passivation layer comprising intermediate products and secondary minerals is a principal challenge in preoxidizing arsenical gold ores.Due to the similar crystal,pyrite(Py) always coexists ...Avoiding the formation of a passivation layer comprising intermediate products and secondary minerals is a principal challenge in preoxidizing arsenical gold ores.Due to the similar crystal,pyrite(Py) always coexists with arsenopyrite(Ap) and effects the oxidation,although its mechanism needs to be improved.Therefore,this study focuses on a mixed leaching system involving Py and Ap.The effects of refactoring the passivation layer structure through Ap oxidation using Py under various pH conditions is systematically investigated.The role of Py in the formation and regulation of the Ap passivation layer is clarified using advanced characterization techniques.The study results indicate that Py decreased the pH,causing the ferric arsenate in the passivation layer of Ap oxidation to become soluble.Furthermore,the addition of Py decreased the jarosite content in the passivation layer.These reconstruction effects of Py on the passivation layer of the Ap surface considerably enhanced Ap oxidation.The highest level of arsenic dissolution(821.43 mg/L) was observed at the mass ratio of Py and Ap at 2(Py/Ap=2),representing an obvious increase compared to the control group(520.96 mg/L).This study focuses on the reconstruction of the passivation layer by Py,and further elucidates the role of Py in enhancing Ap oxidation during the pretreatment of arsenical gold ores,thereby advancing our understanding of the interaction rules between gold-bearing minerals of arsenical gold ores.展开更多
文摘The rate processes of oxidative dearsenication of niccolite ore in microwave oven and in conventional furnace were measured with thermogravimetric technique.The results show that the dearsenication rate of niccolite ore with microwave heating becomes faster than that with conventional heating. Under the conditions of an approximate linear heating and a definite air flow,the oxidative dearsenication process of niccolite ore is mainly controlled by interfacial chemical reaction.The ex- perimental data are in agreement with the kinetic model of linear heating as follows: In{[1-(1-α)^(1/3)]/T}= In (PAM)/(r_oρφE)(1-(RT)/E)-E/(RT) Thus the apparent activation energies of oxidative dearsenication of the niccolite ore containing differ- ent additions have been obtained from the model.
基金supported by the National Natural Science Foundation of China(Nos.52274255 and 52404276)Fundamental Research Funds for the Central Universities(Nos.N2301003,N2201008,N2201004,and N2301025)+2 种基金Postdoctoral Foundation of Northeastern UniversityYoung Elite Scientists Sponsorship Program by CAST(No.2022QNRC001)China Postdoctoral Science Foundation(No.2022M720025)
文摘Avoiding the formation of a passivation layer comprising intermediate products and secondary minerals is a principal challenge in preoxidizing arsenical gold ores.Due to the similar crystal,pyrite(Py) always coexists with arsenopyrite(Ap) and effects the oxidation,although its mechanism needs to be improved.Therefore,this study focuses on a mixed leaching system involving Py and Ap.The effects of refactoring the passivation layer structure through Ap oxidation using Py under various pH conditions is systematically investigated.The role of Py in the formation and regulation of the Ap passivation layer is clarified using advanced characterization techniques.The study results indicate that Py decreased the pH,causing the ferric arsenate in the passivation layer of Ap oxidation to become soluble.Furthermore,the addition of Py decreased the jarosite content in the passivation layer.These reconstruction effects of Py on the passivation layer of the Ap surface considerably enhanced Ap oxidation.The highest level of arsenic dissolution(821.43 mg/L) was observed at the mass ratio of Py and Ap at 2(Py/Ap=2),representing an obvious increase compared to the control group(520.96 mg/L).This study focuses on the reconstruction of the passivation layer by Py,and further elucidates the role of Py in enhancing Ap oxidation during the pretreatment of arsenical gold ores,thereby advancing our understanding of the interaction rules between gold-bearing minerals of arsenical gold ores.
