Aluminum electrolytic cell cathode with aluminum as cathode

Abstract

The invention discloses an aluminum electrolysis cell cathode as which aluminum is adopted, and relates to the improvement on aluminum electrolysis cell production with cryolite aluminum monoxide melt as an electrolyte and through a molten salt method. The cathode is characterized in that the structure of the cathode comprises an electrolysis cell body, cathode partition walls arranged in cell ledges at the two ends of the aluminum electrolysis cell body, and a cathode busbar entering the aluminum electrolysis cell body from side channels formed by the cathode partition walls and the inner walls of the cell ledges at the ends of the aluminum electrolysis cell body, wherein a bottom channel is arranged between the bottoms of the cathode partition walls and the lower bottom of the aluminum electrolysis cell body, and the side channels are formed by the cathode partition walls and the inner walls of the cell ledges at the ends of the aluminum electrolysis cell body. According to the aluminum electrolysis cell cathode as which aluminum is adopted, molten aluminum in which no cathode carbon block, no steel bar and no titanium boride coating exist is adopted as the cathode to replace a cathode composed of steel bars and a carbon block set. The defects that according to a traditional aluminum electrolysis cell, aluminum oxide deposit exists on cathode carbon blocks and cellular micro-batteries exist are eliminated. In the electrolysis production process, the problem that aluminum oxide and aluminum carbide which are deposited and generated at the furnace bottom pollute electrolysis molten aluminum does not exist.

Description

technical field [0001] The invention discloses an aluminum electrolytic cell cathode which uses aluminum as the cathode, and relates to the improvement of an aluminum electrolytic cell produced by a molten salt method using cryolite-alumina melt as an electrolyte. Background technique [0002] At present, conventional electrolytic aluminum production uses cryolite-alumina melt as the electrolyte, carbon as the anode, and a cathode system composed of liquid aluminum, cathode carbon block, and cathode steel rod as the cathode, and a direct current is applied to precipitate CO at the anode. 2 gas, and liquid aluminum is precipitated at the cathode. According to the current technology, the production of 1 ton of metal aluminum needs to consume about 15,000kw h of electricity (combined AC power consumption). Under the process conditions of aluminum electrolysis at 940-960°C, the energy utilization efficiency of aluminum electrolysis is less than 36% (converting the carbon consump...

AI Technical Summary

Problems solved by technology

According to the current technology, the production of 1 ton of metal aluminum needs to consume about 15,000kw h of electricity (combined AC power consumption). Under the process conditions of aluminum electrolysis at 940-960°C, the energy utilization efficiency of aluminum electrolysis is less than 36% (converting the carbon consumption of the anode into for power consumption)

On the cathode carbon block of the traditional electrolytic cell, it is easy to form alumina precipitation. The honeycomb precipitation formed on the carbon block cathode of the traditional aluminum electrolysis cell, and the alumina precipitation formed on the cathode carbon block are affected by the cold and hot state of the electrolytic cell. The precipitation can be in the form of paste, shell or honeycomb. Paste or shell-like precipitation can increase the cell voltage by 400mv-900mv. Honeycomb precipitation not only increases the pressure drop at the bottom of the cathode furnace, but also forms a In the micro-battery with cathode carbon block as the cathode, alumina is generated on the anode of the micro-battery, aluminum carbide is generated on the cathode, and the alumina precipitated on the cathode of the carbon block increases the power consumption of electrolytic aluminum and reduces the current efficiency of aluminum electrolysis. The generated alumina and aluminum carbide cause pollution of the electrolytic aluminum solution, see image 3

[0005] To sum up, in an aluminum electrolytic cell with a traditional structure whose cathode is composed of molten aluminum and cathode carbon blocks, the voltage drop of the cathode steel rod accounts for about 49% of the voltage drop at the bottom of the furnace, which greatly increases the power consumption of aluminum electrolysis; During the use of the cell, the infiltrated electrolyte forms a non-conductive solid electrolyte layer at the carbon-steel contact part, which causes a sharp increase in the carbon-steel contact pressure drop and increases the power consumption of aluminum electrolysis; the alumina formed on the cathode carbon block Precipitation not only increases the pressure drop at the bottom of the cathode furnace, but also forms a micro-battery with aluminum as the anode and cathode carbon block as the cathode. The resulting alumina and aluminum carbide increase the power consumption of electrolytic aluminum and reduce the current efficiency of aluminum electrolysis. At the same time cause electrolytic aluminum pollution

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