The production process of the electrode paste is very simple. The calcined anthracite and metallurgical coke are crushed, sieved, and the ingredients are mixed with coal pitch and kneaded. In order to increase the sintering speed of the electrode paste, a small amount of graphitized metallurgical coke, broken graphite or natural graphite can be added to the ingredients to improve the thermal conductivity of the self-baking electrode and speed up the sintering speed. The anthracite in the ingredients accounts for about 50% or more. The anthracite is crushed to less than 20mm, and the coke is ground into powder and added.
The control of the particle size composition should be based on the principle of large particle density, so that an electrode with high strength and good conductivity can be obtained. When the two particle sizes are mixed, the average particle size of the large particles is required to be at least 10 times the size of the small particles; the number of small particles in the mixture should be 50% to 60%. Generally, the amount of binder added is 20% to 24% of the solid material. Various materials are weighed according to the proportion and then added to the kneader. The kneading temperature should be more than 70℃ higher than the softening point of the binder, and the stirring time should not be less than 30 minutes.
The outer layer of the continuous self-baking electrode is a cylinder made of 1-2mm steel plate, and the electrode paste is regularly added to the cylinder. As the production progresses, the lower electrode is gradually consumed and the electrode paste moves down. The high temperature causes the electrode paste to gradually soften and melt as the electrode paste continues to move down. Under the action of higher temperature, the molten electrode paste will be coked, and finally the electrode paste will be transformed into Conductive electrode.