The electrode paste is also called self baking electrode. It relies on the heat in the submerged arc furnace to complete the baking. Therefore, the matching of the consumption speed of the electrode and the baking speed is the key to the use of the electrode paste. Due to the development of the submerged arc furnace technology, the electrode is gradually developed in the direction of large-scale and closed furnace. In the baking process, the electrode is developed from the open furnace type to the closed furnace type, and the heat obtained by the electrode from the furnace is greatly reduced, This requires improving the sintering performance of the electrode paste to make up for this deficiency. For the manufacturers of electrode paste, the two major problems that * is taboo are electrode soft break and hard break, of which soft break is more terrible and easy to cause accidents.
Hard fracture is caused by insufficient strength of electrode paste after sintering; Soft fracture refers to that the sintering speed of the electrode is lower than the consumption speed, and the electrode is too fast. The electrode is not fully sintered and cannot withstand the tension and lateral impact at the lower part of the electrode, resulting in fracture. These two problems are directly related to the performance of the electrode paste of the carbon manufacturer, and also related to the operation in the process of use. There are only two main links in the production of electrode paste, namely, batching and kneading. Among them, the kneading is basically the same at present, as long as the kneading equipment is regular equipment (above 2000L intermittent double shaft kneading pot), and the kneading temperature and time can be well controlled in the process. The key of ingredient is rational formula; The selection of raw materials and particle size ratio, especially the softening point of binder asphalt and the amount of binder used.
At present, the main problem perplexing manufacturers is that the roasting speed of electrode paste is too slow, so some manufacturers adopt the method of reducing the use of asphalt. This method is effective to a certain extent, but the too low asphalt content causes poor fluidity of the electrode paste, and the electrode paste is not easy to be filled in the electrode barrel. The poor compactness after sintering is easy to cause hard fracture. Another method is to reduce the softening point of the asphalt and improve the electrode sintering speed. However, the softening point of the asphalt can not be reduced without limitation, because the asphalt with too low softening point reduces the coking rate of the asphalt, The strength of the electrode should also be reduced, or the hard break phenomenon should occur.
Therefore, in addition to properly mastering the above two methods, the production of electrode paste should also improve the sintering speed of the electrode through the adjustment of the formula. For example, the graphite raw materials with good conductivity and heat transfer performance should be appropriately added in the formula to increase the conduction heat obtained by the electrode from the furnace, so as to speed up the baking speed. At the same time, try to reduce the consumption of the electrode to reduce the lowering speed of the electrode, so as to match the electrode consumption and baking. I began to study the production technology of electrode paste in the 1980s, and conducted experiments for the production of electrode paste in the electric nickel furnace of Northwest Jinchang company. I also added certain additives to asphalt, which also had certain effects. After that, he successively developed products for many large calcium carbide furnaces and ferroalloy furnaces, and gained certain experience. Therefore, the production of electrode paste should be tailored to the symptoms, multi pronged, comprehensive consideration, appropriate and complementary advantages, so as to produce good products and obtain the satisfaction of users.