The anode carbon block is generally a rectangular parallelepiped, with 2-4 circular grooves on the upper surface of the conductive direction, whose diameters are from 160 to 180mm and the depths are between 80 and110mm. These circular grooves are often called carbon bowls. When assembling the anode carbon block, the carbon bowl is used to hold the anode claw head, and the anode lead rod and the anode carbon block are connected as a whole by casting phosphorous pig iron to form the anode carbon block group. The anode carbon block has different sizes according to the size of the electrolytic cell current and the process, but the current density through it is generally 0.70-0.76A/cubic centimeter, and the service period is 20-28 days.
The anode carbon block is directly placed in the electrolyte of the aluminum electrolytic cell and participates in the anode reaction. The production process and conditions of use require it to have the following characteristics:
(1) Low impurity content. The raw materials used are all ash-less petroleum coke, pitch coke, and coal pitch, so the impurity content is less than 1.0%.
(2) The anode carbon block has been roasted, and harmful fumes have been volatilized. This can improve the labor environment of electrolysis production and is conducive to environmental protection.
(3) Low resistivity
(4) Forming and roasting are carried out by using a special process. The volume of the product is compact, has good mechanical properties, and the compressive strength is greater than 30MPa.