Performance indicators and applications of carbon bricks for submerged arc furnaces

In the production of ferroalloys, submerged arc furnaces are important thermal equipment for reducing and smelting raw ores into high-temperature liquids. The raw materials that can be used for smelting include ferrosilicon, industrial silicon, calcium silicon alloy, high carbon ferromanganese, manganese silicon alloy, high carbon Ferrochromium, silicon-chromium alloy, silicon-aluminum alloy and rare earth alloy, etc. are also used to smelt pig iron, calcium carbide, yellow phosphorus, nickel matte and corundum and other products.

Submerged arc furnaces usually use carbon or magnesia refractory materials as furnace linings, and use self-baking electrodes. The electrodes are inserted into the charge to perform submerged arc operation, with continuous feeding, intermittent tapping of iron and slag, and continuous operation. The heat of the submerged arc furnace mainly comes from the Joule heat of the melt resistance, and the arc heat is less or there is no arc.

The main raw materials for making carbon bricks are crushed coke and anthracite, and the binder is coal tar or asphalt.

Compared with other ordinary refractory materials, carbon bricks not only have high compressive strength, small thermal expansion coefficient, good wear resistance, high refractoriness and load softening temperature, good resistance to rapid cooling and rapid heating, but also particularly good slag resistance. Therefore, carbon bricks can be used as submerged arc furnace lining materials for all types of ferroalloys that are not afraid of carburization.

However, carbon bricks are easily oxidized under high temperature conditions, and their thermal and electrical conductivity coefficients are large. In ferroalloy production, carbon bricks are mainly used to build the furnace walls and furnace bottoms of submersible furnaces that are not exposed to air.