Slow sintering of ferrosilicon furnace electrode paste
Heat source and sintering process for electrode paste sintering.
1. Heat source for electrode paste sintering. The electrode has a high carbon content, and its own electrical and thermal conductivity is excellent; the resistance heat generated by the current passing through the electrode itself (the resistance of the ferrosilicon electrode paste is generally around 70, and the resistance of the nickel-iron electrode paste is slightly lower at about 65. In sub-fields, this resistance is still relatively high. You must know that the resistance of the graphite electrode is about 5.); The conduction and radiation of the furnace surface flame (the domestic submerged arc furnace is submerged arc operation, and this operation makes the contact surface more generated. Large heat, then this heat can be conducted by the electrode paste after sintering.)
2. The process of electrode paste sintering. The boundary of the change process of electrode paste during sintering is not very obvious, but in order to facilitate research and control, according to the temperature and position of sintering, it can be roughly divided into three stages:
(1) Softening stage. The temperature rises from 25 degrees to 120-200. It is roughly 50cm above the electric jaw.
(2) The volatilization stage. The temperature rises from 120-200 to 650-750, roughly in the half-ring position.
(3) The sintering stage. The temperature rose from 650-750 to 900-1000.
3. The problem of slow sintering of electrode paste. In the submerged arc furnace, there is a way to judge whether the electrode sintering is normal: if the electrode surface is found to be off-white or dark but not red, the sintering is good; if the sintering is found to be red, it is too dry; if it is black or smokey , It is sintered too soft. In our opinion, the so-called slow sintering of electrode paste must be accompanied by redness of electrode sintering. If electrode sintering is too slow, hard-breaking accidents will occur.
Generally speaking, three aspects should be considered as the cause of the accident: submerged arc furnace equipment problem; worker operation problem; electrode paste quality problem. Because equipment problems are quantitative, the equipment under normal conditions is the same as the equipment in the event of an accident. Then we must consider the issues of worker operation and the quality of the electrode paste. The daily operations of workers are not the same, such as when to increase the load, when to reduce the load, and so on. Electrode paste quality problem: The quality of electrode paste depends on the ratio of electrode paste raw materials. It is not very sure that the quality of electrode paste from different batches of electrode paste factory is exactly the same. In Rongxin Carbon Electrode Paste Plant, the formula of each plant is different. For long-term and stable customers, we will supply every month, and we can achieve the same quality every month.