The values of GΘ,EΘ or pH from 110 to 160℃ were calculated and the relevant potential expressions were obtained.E-pH diagrams of ZnS-H2O system at oxygen partial pressure of 0.8 MPa,ionic activity of 1.0 and differ...The values of GΘ,EΘ or pH from 110 to 160℃ were calculated and the relevant potential expressions were obtained.E-pH diagrams of ZnS-H2O system at oxygen partial pressure of 0.8 MPa,ionic activity of 1.0 and different temperatures were drawn through thermodynamical calculation.With the temperature increasing,the stable regions of S and Zn(Ⅱ) in the E-pH diagrams become gradually larger,but the amplification decreases over 150℃.The impacts of leaching parameters,such as temperature,liquid to solid ratio,initial acidic concentration,leaching time,oxygen partial pressure and stirring speed on the leaching rate of Zn(Ⅱ) and conversion rate of S in the single factor of high pressure leaching experiment of ZnS in autoclave,were studied.The leaching residue was examined by X-ray fluorescence(XRF) chemical composition identification and X-ray diffraction(XRD) phase identification,and the content of the leaching solution was tested by inductively coupled plasma-atomic emission spectrometry(ICP).The experimental results indicate that the leaching rate of zinc increases from 60.05% to 97.85% and the conversion rate of sulfur increases from 38.90% to 80.92% with the temperature increasing from 110℃ to 150℃,5:1 of liquid-to-solid ratio,150 g/L of initial acidic concentration,120 min of leaching time,0.8 MPa of oxygen partial pressure,and 480 r/min of stirring speed,which tend to be stable over 150℃.The experimental results correspond with theoretical calculation.展开更多
Influence mechanism of sulfide ions(S^2-) during manganese electrodeposition from sulphate electrolyte was investigated. Under the experimental conditions, S^2- ion concentration and electrolyte pH represented signifi...Influence mechanism of sulfide ions(S^2-) during manganese electrodeposition from sulphate electrolyte was investigated. Under the experimental conditions, S^2- ion concentration and electrolyte pH represented significant multiple effects on the cathode current efficiency. Scanning electron microscope(SEM) indicated that electrodeposition manganese layer(EML) became refinement as S^2- ion concentration was increased. X-ray Diffraction(XRD) displayed that S^2- ion had negligible influence on the preferred orientation of the crystalline layer of the EML. S^2- ion had no influence on the chemical composition of EML. S^2- ion could improve the corrosion resistance of EML. The interaction mechanism of S^2- ion with manganese electrodeposition was systematically explored by analysing E-pH diagram, cyclic voltammetry curve, cathode polarization curve and electrochemical impedance method.展开更多
基金Project (2007CB613504) supported by the National Basic Research Program of ChinaProject(20050145029) supported by the PhD Programs Foundation of Ministry of Education of ChinaProject(2005221012) supported by the Science and Technology Talents Fund for Excellent Youth of Liaoning Province, China
文摘The values of GΘ,EΘ or pH from 110 to 160℃ were calculated and the relevant potential expressions were obtained.E-pH diagrams of ZnS-H2O system at oxygen partial pressure of 0.8 MPa,ionic activity of 1.0 and different temperatures were drawn through thermodynamical calculation.With the temperature increasing,the stable regions of S and Zn(Ⅱ) in the E-pH diagrams become gradually larger,but the amplification decreases over 150℃.The impacts of leaching parameters,such as temperature,liquid to solid ratio,initial acidic concentration,leaching time,oxygen partial pressure and stirring speed on the leaching rate of Zn(Ⅱ) and conversion rate of S in the single factor of high pressure leaching experiment of ZnS in autoclave,were studied.The leaching residue was examined by X-ray fluorescence(XRF) chemical composition identification and X-ray diffraction(XRD) phase identification,and the content of the leaching solution was tested by inductively coupled plasma-atomic emission spectrometry(ICP).The experimental results indicate that the leaching rate of zinc increases from 60.05% to 97.85% and the conversion rate of sulfur increases from 38.90% to 80.92% with the temperature increasing from 110℃ to 150℃,5:1 of liquid-to-solid ratio,150 g/L of initial acidic concentration,120 min of leaching time,0.8 MPa of oxygen partial pressure,and 480 r/min of stirring speed,which tend to be stable over 150℃.The experimental results correspond with theoretical calculation.
基金Funded partly by the National Natural Science Foundation of China(No.21376273)the National Science and Technology Support Program of China(No.2015BAB17B01)the Open Research Fund of Hunan Provincial Science and the Technology Plan Project(No.MN2017K05),China
文摘Influence mechanism of sulfide ions(S^2-) during manganese electrodeposition from sulphate electrolyte was investigated. Under the experimental conditions, S^2- ion concentration and electrolyte pH represented significant multiple effects on the cathode current efficiency. Scanning electron microscope(SEM) indicated that electrodeposition manganese layer(EML) became refinement as S^2- ion concentration was increased. X-ray Diffraction(XRD) displayed that S^2- ion had negligible influence on the preferred orientation of the crystalline layer of the EML. S^2- ion had no influence on the chemical composition of EML. S^2- ion could improve the corrosion resistance of EML. The interaction mechanism of S^2- ion with manganese electrodeposition was systematically explored by analysing E-pH diagram, cyclic voltammetry curve, cathode polarization curve and electrochemical impedance method.
