The electrode is a key part of the ferroalloy submerged arc furnace, and keeping the electrode in a normal state is of great significance to the ferroalloy enterprise. Electrode accidents are common in that the electrode paste is hard broken, and a considerable part of the electrode hard broken is caused by the local strength of the electrode due to the segregation of particles during the sintering process.
The main reasons for the segregation of electrode paste are as follows:
1. The influence of electric furnace operation
1.1 When the current density is too large, the electric furnace is often in overload operation. The resistance heat generated when the current passes through the electrode is large, and the temperature distribution on the electrode section moves up in the high temperature area.
1.2 The air supply in the electrode holding barrel is small or the air is stopped, the circulating water volume in the copper tile is small, the water temperature is high, the conductive plate is not cooled enough, and the electrode paste melts like water.
1.3 The electric furnace is not operating normally, the open arc is operated, the stinging is serious, the radiant heat of the furnace mouth and the convection heat of the gas are increased, and the electrode paste is melted too fast after being added.
2. Influence of electrode paste characteristics
Scientists of the former Soviet Union have conducted in-depth research on the migration process of asphalt. They believe that the coarser the particle size composition, the easier it is for the binder to migrate under the same temperature condition. The binder content is under the same temperature condition and the same particle size composition. The more, the greater the degree of migration, and the lower the softening point of the asphalt, the greater the degree of migration.
The actual experiment also proves that the above conclusion is correct. The electrode paste softens prematurely. The lower the softening point of the electrode paste, the easier it is for large particles to delaminate. There are two main reasons for the low softening point:
1. The size of the electrode paste particles is too large, and the amount of large particles is too much.
2. The softening point of asphalt is too low and the volatile content is high