In the process of aluminum electrolysis, the high temperature, toxic and aggressive cryolite solution directly contacts with the motor fluid. As the conductive anode and cathode materials, carbon material is the only one with good conductivity, high temperature resistance, corrosion resistance and low price.
Prebaked anode block is made of petroleum coke and asphalt coke as aggregate and coal tar pitch as binder. It is used as anode material for prebaked aluminum reduction cell.
The prebaked anode block is usually installed on the top of the electrolytic cell. The strong dc current of 60-300ka is introduced into the electrolyte through the carbon anode. The resistivity of carbon anode is 50-70 μ Ω. M. with the resistance of guide rod and contact point, the voltage drop of carbon anode consumed in normal aluminum electrolysis production is 300-500 MV, accounting for 10% - 15% of the cell voltage drop.