Use and production of electrode paste
Electrode paste is also called self-baking electrode. It relies on the heat in the submerged arc furnace to complete the roasting. Therefore, matching the consumption speed of the electrode with the roasting speed is the key to the use of electrode paste. Due to the development of submerged arc furnace technology, it is gradually becoming large With the development of the electrode in the sintering process from open furnace to closed furnace, the heat obtained by the electrode from the furnace is greatly reduced, which requires the improvement of the sintering performance of the electrode paste to make up for this deficiency.
Hard fracture is caused by insufficient strength of the electrode paste after sintering; soft fracture is that the electrode sintering speed is not as fast as the consumption rate, and the lowering is too fast. The electrode is not completely sintered and cannot withstand the stretching and lateral impact of the lower part of the electrode, causing fracture. These two problems are directly related to the performance of the electrode paste of the carbon manufacturer, and are also related to the operation during use.
There are only two main steps 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 a regular equipment (a discontinuous double-shaft kneading pot above 2000L) and the kneading temperature and time can be controlled in the process. The key to the ingredients is a reasonable formula; the selection of raw materials, the particle size ratio, and the softening point of the binder asphalt and the amount of binder used are especially important.
At present, the main problem that plagues manufacturers is that the electrode paste baking speed is too slow, so some manufacturers adopt methods to reduce the amount of asphalt used. This method is effective to a certain extent, but too low amount of pitch causes the fluidity of the electrode paste to deteriorate, and the electrode paste is not easy to be filled in the electrode cylinder. After sintering, the density is poor and it is easy to cause hard fracture. Another method is to reduce the pitch. The softening point of the electrode increases the sintering speed of the electrode, but the softening point of the pitch cannot be reduced indefinitely, because the pitch with a too low softening point reduces the pitch coking rate, and the strength of the electrode is also reduced, or the phenomenon of hard fracture occurs.
Therefore, in addition to properly mastering the above two methods in the production of electrode paste, the sintering speed of the electrode must be improved through the adjustment of the formula. The conduction heat obtained in the furnace can speed up the firing speed, and at the same time try to reduce the consumption of the electrode to reduce the speed of the electrode lowering, which can also achieve the matching of the electrode consumption and the firing.