Cell voltage is a widely used signal that can be measured online from an industrial aluminum electrolysis cell.A variety of parameters for the analysis and control of industrial cells are calculated using the cell vol...Cell voltage is a widely used signal that can be measured online from an industrial aluminum electrolysis cell.A variety of parameters for the analysis and control of industrial cells are calculated using the cell voltage.In this paper,the frequency segmentation of cell voltage is used as the basis for designing filters to obtain these parameters.Based on the qualitative analysis of the cell voltage,the sub-band instantaneous energy spectrum(SIEP)is first proposed,which is then used to quantitatively represent the characteristics of the designated frequency bands of the cell voltage under various cell conditions.Ultimately,a cell condition-sensitive frequency segmentation method is given.The proposed frequency segmentation method divides the effective frequency band into the[0,0.001]Hz band of lowfrequency signals and the[0.001,0.050]Hz band of low-frequency noise,and subdivides the lowfrequency noise into the[0.001,0.010]Hz band of metal pad abnormal rolling and the[0.01,0.05]Hz band of sub-low-frequency noise.Compared with the instantaneous energy spectrum based on empirical mode decomposition,the SIEP more finely represents the law of energy change with time in any designated frequency band within the effective frequency band of the cell voltage.The proposed frequency segmentation method is more sensitive to cell condition changes and can obtain more elaborate details of online cell condition information,thus providing a more reliable and accurate online basis for cell condition monitoring and control decisions.展开更多
The electrolyte circulations in monopolar cell and two-compartment bipolar cell with submerged electrodes were described by a hydraulic model.The influence of current density,electrode tilt,anode-cathode distance(ACD)...The electrolyte circulations in monopolar cell and two-compartment bipolar cell with submerged electrodes were described by a hydraulic model.The influence of current density,electrode tilt,anode-cathode distance(ACD)and immersion depth of electrodes on the electrolyte circulation velocities between electrodes had been studied.Results demonstrated that the flow rates in the two compartments of bipolar cell were very different,which provided important information for the structure design of bipolar cell.展开更多
With alumina sol as binder and Ni metal as sintering aids,the Ni-TiB_(2)/Al_(2)O_(3) composite cathode material for aluminum electrolysis was prepared by coldpressed sintering.The mechanical properties of the composit...With alumina sol as binder and Ni metal as sintering aids,the Ni-TiB_(2)/Al_(2)O_(3) composite cathode material for aluminum electrolysis was prepared by coldpressed sintering.The mechanical properties of the composite cathode material were measured.Its electrolytic properties were identified by a 20-A electrolysis test.Cathode samples before and after electrolysis test were measured by energy-dispersive spectroscopy(EDS).The migration behavior of various elements in the electrolysis process was studied by phase analysis.The result shows that Ni metal can effectively fill the gap between the aggregate during the sintering process,which can improve the sintering density of the composite cathode material significantly.The voltage of the 20-A electrolysis test is stable.The impurity of aluminum liquid is 0.42%.The aluminum liquid can wet the cathode surface effectively,and the Ni-TiB_(2)/Al_(2)O_(3) composite is an ideal wettable cathode material.In the process of electrolysis,the alkali elements in the electrolyte penetrate the electrode,where K goes deeper than Na.Al generated on the cathode surface will also penetrate the cathode through the gap of the composite material,while Ni in the electrode will spread into the aluminum liquid layer.展开更多
基金This work was supported by the Program of the National Natural Science Foundation of China(61988101,61773405,and 61751312).
文摘Cell voltage is a widely used signal that can be measured online from an industrial aluminum electrolysis cell.A variety of parameters for the analysis and control of industrial cells are calculated using the cell voltage.In this paper,the frequency segmentation of cell voltage is used as the basis for designing filters to obtain these parameters.Based on the qualitative analysis of the cell voltage,the sub-band instantaneous energy spectrum(SIEP)is first proposed,which is then used to quantitatively represent the characteristics of the designated frequency bands of the cell voltage under various cell conditions.Ultimately,a cell condition-sensitive frequency segmentation method is given.The proposed frequency segmentation method divides the effective frequency band into the[0,0.001]Hz band of lowfrequency signals and the[0.001,0.050]Hz band of low-frequency noise,and subdivides the lowfrequency noise into the[0.001,0.010]Hz band of metal pad abnormal rolling and the[0.01,0.05]Hz band of sub-low-frequency noise.Compared with the instantaneous energy spectrum based on empirical mode decomposition,the SIEP more finely represents the law of energy change with time in any designated frequency band within the effective frequency band of the cell voltage.The proposed frequency segmentation method is more sensitive to cell condition changes and can obtain more elaborate details of online cell condition information,thus providing a more reliable and accurate online basis for cell condition monitoring and control decisions.
文摘The electrolyte circulations in monopolar cell and two-compartment bipolar cell with submerged electrodes were described by a hydraulic model.The influence of current density,electrode tilt,anode-cathode distance(ACD)and immersion depth of electrodes on the electrolyte circulation velocities between electrodes had been studied.Results demonstrated that the flow rates in the two compartments of bipolar cell were very different,which provided important information for the structure design of bipolar cell.
基金financially supported by the Major Science and Technology Projects of Henan Province(No.131100210700)the Major Science and Technology Programs of CHALCO(No.ZB2013CBBCe1)。
文摘With alumina sol as binder and Ni metal as sintering aids,the Ni-TiB_(2)/Al_(2)O_(3) composite cathode material for aluminum electrolysis was prepared by coldpressed sintering.The mechanical properties of the composite cathode material were measured.Its electrolytic properties were identified by a 20-A electrolysis test.Cathode samples before and after electrolysis test were measured by energy-dispersive spectroscopy(EDS).The migration behavior of various elements in the electrolysis process was studied by phase analysis.The result shows that Ni metal can effectively fill the gap between the aggregate during the sintering process,which can improve the sintering density of the composite cathode material significantly.The voltage of the 20-A electrolysis test is stable.The impurity of aluminum liquid is 0.42%.The aluminum liquid can wet the cathode surface effectively,and the Ni-TiB_(2)/Al_(2)O_(3) composite is an ideal wettable cathode material.In the process of electrolysis,the alkali elements in the electrolyte penetrate the electrode,where K goes deeper than Na.Al generated on the cathode surface will also penetrate the cathode through the gap of the composite material,while Ni in the electrode will spread into the aluminum liquid layer.
