Method for extending service life of refining electric furnace lining 3

Raw materials generally contain moisture to varying degrees, especially in the south. Due to the large amount of rain, the manganese ore will be wetted by rain during the transfer or storage. To ensure the drying of the raw materials into the furnace, you can use a rotary kiln to dry and then re-enter Furnace smelting, which can not only reduce production costs, but also reduce the corrosion of raw materials to the lining.

(1) Requirements for pile bottom material
The use of manganese silicon processing powder to start the bottom of the arc can reduce the damage of the electrode arc to the bottom of the furnace. Under normal circumstances, 40% of the manganese silicon can be extracted from the bottom of the stack, which can prevent the rapid consumption of the bottom of the furnace.
However, when the furnace bottom consumption is slow and the furnace wall consumption is too fast, the life of the furnace lining will also be reduced. At this time, the pile bottom material should be canceled immediately, and all the mixtures are mixed into the furnace, so as to ensure that the furnace bottom and the furnace wall are synchronized and reasonable Consumption.

(2) Smelting time requirements of the first three furnaces
In order to ensure that the furnace bottom sintering meets the requirements, the phenomenon of turning the furnace bottom does not occur in the subsequent production process. The smelting time of the first furnace is 2h longer than the normal furnace time, and the second furnace can be extended appropriately. From the third furnace It can be produced normally at the beginning.

(3) Make up the furnace in time
During the furnace bottom consumption process, there will be a phenomenon of rapid damage to the furnace wall. If the furnace is not repaired in time, the entire furnace lining will be destroyed. Therefore, when it is found that the furnace wall is partially seriously damaged, it is necessary to stop and clean the slag hanging on the furnace lining around the damaged area, and then fill the configured supplementary furnace charge into it for tamping, and then cut and send electricity to produce. Especially on both sides of the tap hole, the molten iron is severely eroded here when tapping, and it must be repaired frequently.

(4) Adjust the polar center circle in time
The requirements for the polar center circle are different in the early and later stages of the furnace lining. The furnace bottom is thicker in the early stage and the electrode position is higher. The distance between the three-phase electrode and the furnace wall is too large. The distance to the furnace wall becomes smaller, and at the same time, the electrode facet furnace wall becomes thinner. If the polar center circle is not adjusted in time, the furnace wall will be damaged quickly. Generally, in the middle and later stages of the furnace lining, the polar center circle should be reduced a little. It can ensure the extension of the life of the lining.
When producing low- and medium-carbon ferromanganese, there are stricter requirements on the secondary voltage. The 3MVA electric furnace uses 5 levels of voltage or 153.7V for power transmission. No voltage adjustment is required during the production process. If the voltage is too high, the arc will be too long in the later stage of production, which will damage the lining. If the voltage is too low, the smelting chemical material will take too long, and the lining will be damaged. Therefore, we must insist on the use of appropriate secondary voltage production to help extend the life of the lining.

In order to reduce the degree of damage to the furnace lining by peak avoidance, measures need to be taken to protect the furnace lining, the specific measures are as follows:
1. The last molten iron must be clean, the purpose is to prevent the molten iron from eroding the bottom of the furnace during the furnace shutdown;
2. After the last furnace iron is finished, the materials must be prepared according to the process requirements, and the furnace is filled with materials to insulate the furnace lining to prevent it from being weathered.
Through the analysis of the production characteristics of refining electric furnace, the method of extending the service life of the lining is explained from the aspects of lining materials, product raw materials, production process, electricity system and peak avoidance production. The service life of the ferromanganese lining can be extended from about 400 furnaces to 800 furnaces.