| Increasing current is one of the effective measures to increase products of aluminum reduction cells and economic profit in aluminum reduction plant. As the current density of the anode in most aluminum reduction cells is low comparatively in our country, improving current has great potential. It is significance to study ways of increasing current and relative technologies for increasing product and profit of aluminum electrolyte plants in China.Aluminum electrolysis is a process of complicated physical chemistry reaction with multi-field coupled. It is indispensable to study increasing current influence on" three field " The variation of thermal field in the Based on and relative technologies after intensifying current are mainly studied in this paper by means of practical measure and computer simulation.Aiming at the current increasing of the aluminum reduction cell of Longxiang Aluminum Ltd, based on the special simulation software of the thermal field of aluminum reduction cells, which is developed and perfected by school of Energy and Power Engineering, Central South University. The author studied excellence and disadvantage of two designs of enhancing current, optimization of technical parameters and variety of cell material in the cell, which are enhancing current density of anode and enlarging size of anode. Furthermore, asymmetry of current distribution influence on shape of profile ledge in the cell is studied and the reason is analyzed. The technical approach is put forward to improve the uniform distribution of anode current. The following conclusion has been achieved by means of simulation calculation and project test.1. Under existing technical conditions, it is feasible to intensify current of the aluminum reduction cell of Longxiang Aluminum Ltd. from 154 kA to 160kA by means of appropriate technology measures. Furthermore, the current intensifying design of increasing current density of anode is superior to the one of enlarging anode in economy.2. To Substitute anti-penetration material for the firebrick is beneficial to the heatpreservation in the bottom of aluminum reduction cells and the prolonging of the cells life.3. To substitute ordinary brick made of carbon for brick made of Carborundum in the profile of the cells intensifies dispersion of heat in the profile of the cells and the capability of withstanding erosion of electrolyte. It is beneficial to the formation of optimized profile ledge, the increase of current and the prolonging of the cells life.4. The super heat of electrolysis influences the shape of profile ledge in the cell.. This paper pointed out that the appropriate super heat of the electrolysis is between 12~15 C under present technology condition in the Longxiang Aluminum Ltd.5. The decrease of molecule ratio can enhance current efficiency of aluminum reduction cells effectively, but simultaneously bring out some disadvantageous such as the decrease of profile ledge thickness and the moving down of the isotherm. Decreasing super heat properly can make up negative influences caused by lower molecule ratio.6. The uniform distribution of anode current influences the shape of profile ledge in the cells definitively. Increasing asymmetry of anode current distribution is not beneficial to improving current efficiency and decreasing energy consumption The study indicated that the different distance between anode and cathode and the anode carbon consumption influence the uniformity of anode current distribution Heating new anode, regulating the distances between anode and cathode on the basis of measure of on-line of anode current, intensifying quality inspection of cast-material made of phosphor-iron can improve uniformity of anode current distribution effectively.7. A serial of relative measures to increasing current have been put forward and applied. Such as to lengthen anode and cathode, to decrease distances between anode and cathode and reduce molecule ratio properly, and so on. Good effects have achieved the Longxiang Aluminum Ltd.
|
PDF Full Text Request