Configuration analysis of electric furnace ramming material in the lining of electric arc furnace

The electric arc furnace uses the high temperature generated by the electric arc to smelt ore and metal. The energy is concentrated when the gas discharge forms the arc. The arc zone temperature is above 3000 ℃. For smelting metals, the electric arc furnace is more flexible than other steelmaking furnaces and can effectively Removal of impurities such as sulfur and phosphorus, the furnace temperature is easy to control, the equipment occupies a small area, and is suitable for the melting of good alloy steel. The following is the corrosion mechanism of refractory lining for a 100t high-power electric arc furnace used in a large steel plant in China. analyze.

1. Refractory materials used for furnace type and qualified parts

A steel joint-stock company’s 100t high-power electric arc furnace has an eccentric furnace bottom tapping form. The upper furnace shell has a water-cooled plate frame structure, and the lower furnace shell has a vertical peripheral butterfly-shaped bottom. The shell is one for one use. After the service life of the furnace expires, the furnace shell is replaced as a whole, and the furnace shell is rebuilt for standby off-line. The main parts of the furnace lining are made of refractory materials.

2. Refractory corrosion mechanism analysis for furnace lining

After a certain steel electric furnace was rebuilt and resumed production, the service life of the furnace lining was 3000 furnaces, and the output was about 30,000 tons. During the use of the furnace, wet gunning of the furnace wall and magnesia ramming material pad furnace slope were adopted to protect the furnace. The replenishment material consumption is 1.7Kg/t, the ramming material consumption is 2.3Kg/t, and the refractory material cost is 45 yuan/t, which has not reached the ideal service life. The off-line furnace lining refractory material corrosion situation is measured.

The refractory material of the furnace lining is affected by the material impact of the scrap steel charge, the radiation and reflection of the arc light, the chemical erosion of the molten steel and the slag, etc., especially at the steel-slag interface, it is subject to the material penetration and chemical erosion of the highly oxidizing slag , Causing the graphite on the working surface of the magnesia-carbon brick to be oxidized to form a loose decarburized structure. After high temperature oxidation, decarburization, and erosion, it will be lost in molten state and flaked state under heat and steel slag erosion. , The furnace lining in the hot zone of the power supply is irradiated by the high temperature of the arc, and the furnace lining in the region of the furnace wall is eroded by the local slag steel circulation, which makes the furnace lining in these two areas seriously damaged. The furnace bottom and the furnace slope are beaten with magnesia ramming material. The result is that the knotting of the early masonry furnace is not compact and the oven sintering is not good. The magnesia working layer has loose defects. Under the action of bottom blowing and stirring, the molten slag infiltrates and reacts with the magnesia to form iron-rich magnesium fusterite. Reduce the melting point of magnesia and accelerate the dissolution of magnesia. At the same time, when the sintering is insufficient in the early stage of the furnace, it is subject to the impact, vibration and impact of the charging, forming local potholes at the bottom of the furnace, causing local area damage too fast.

The content of the article comes from the Internet, if you have any questions, please contact me to delete it!