Lv Xiaojun

Al2O3‐Na3AlF6 Man‐Made Ledge Composites for Aluminum Electrolysis Cells

Man-made Al2O3-Na3AlF6 composite ledge for aluminum reduction cell was developed because of the disadvantages of traditional self-forming ledge and the composite material was prepared by pressureless liquid-phase sintering under air atmosphere. The effect of Na3AlF6 mass fraction on the relative density, compressive strength, high-temperature stability and microstructure of Al2O3-Na3AlF6 composites was investigated. The results show that with the increasing of Na3AlF6 mass fraction from 0 to 15 wt%, the relative density increases from 62.05 % to 67.19 %, the compressive strength increases from 9.74 MPa to 17.81 MPa, and the high-temperature stability of composites under 1100 °C gradually becomes worse. However, compared to traditional self-forming ledge, Al2O3-Na3AlF6 composites have more excellent high-temperature stability. Such results indicate that Al2O3-Na3AlF6 composite is a promising man-made ledge for aluminum reduction cell.

Development of Low‐Voltage Energy‐Saving Aluminum Reduction Technology

In this study, the representative low-voltage energy-saving techniques for aluminum reduction in recent years in China is reviewed, and two low-voltage energy-saving techniques are described, which include the technique based on innovation of the electrolytic technology and the process control and the one based on comprehensive innovation of cell structure, the electrolytic technology and the process control. The results show that the best energy consumption index can be realized with the application of low-voltage technology and advanced process control technique on the cells designed at the concept of “conventional planar cathode + suitable heat preservation enhancing”.

Furan Resin and Pitch Blends as Binders for TiB2-C Cathodes

Blends of furan resin and pitch were applied as the binder of TiB2-C cathodes. Characteristic properties of both the binder and furan/pitch based TiB2-C cathodes were studied. The actual coking value of furan/pitch binder was higher than the theoretical value calculated from the coking values of the two components. There was a synergistic effect between pitch and furan resin. This leads to TiB2-C cathode materials with lower open porosity and electrical resistivity and higher bulk density and compressive strength than those of pure pitch based TiB2-C cathode materials. In addition, the low-temperature electrolysis expansion of TiB2-C samples was tested. Furan/pitch based TiB2-C samples showed lower electrolysis expansion than pitch based TiB2-C samples (1.68% and 1.87%, respectively). Molecular structure (FTIR) and semicoke morphology (SEM) analysis results indicated that after adding an appropriate amount of furan resin, the pitch binder had improved cohesion and flexibility.