Briefly describe 8 applications of magnesia carbon bricks in converters

Magnesia carbon bricks are one of the most widely used bricks in converters. In converters, there are 8 parts where magnesia carbon bricks are frequently used. Due to the different working conditions of each part of the converter, the requirements for magnesia carbon bricks in different parts also vary. Below, we briefly discuss the requirements for magnesia carbon bricks in the 8 parts of the converter.

(1) Furnace Mouth:
Due to the drastic temperature changes at the furnace mouth, severe erosion from slag and high-temperature waste gas, and impacts during scrap removal and charging, the refractory materials used at the furnace mouth must have high thermal shock resistance and slag resistance, be resistant to slag and high-temperature waste gas erosion, not easily adhere to steel, and be easy to clean.

(2) Furnace Hood:
The furnace hood is a part severely eroded by slag, also subjected to temperature changes, carbon oxidation, and erosion from dusty waste gas. Therefore, magnesia carbon bricks with strong slag resistance and thermal shock resistance are required.

(3) Charging Port:
During blowing, the splashing of slag and molten steel easily causes chemical corrosion, wear, and erosion on the charging side. Additionally, the charging side suffers direct impact and erosion from charging scrap and molten iron, causing severe mechanical damage. Therefore, magnesia carbon bricks must not only have high slag resistance and considerable high-temperature strength but also possess good thermal shock resistance. Usually, high-strength magnesia carbon bricks with added antioxidants are used.

(4) Tapping Port:
The tapping side basically does not suffer mechanical damage during charging, and thermal shock effects are relatively small. However, it is subjected to thermal impact and erosion from molten steel during tapping, with a damage rate much lower than the charging side. When using the same material as the charging side, a thinner construction than the charging side is used to maintain balanced service life of the converter lining.

(5) Slag Line Area:
The slag line is a part that is in long-term contact with slag and suffers severe slag erosion. On the tapping side, the position corresponding to the slag changes with tapping time and is often not obvious. On the slag tapping side, due to intense slag erosion and the combined effects experienced by the furnace belly during blowing, damage is severe. Therefore, magnesia carbon bricks with excellent slag resistance need to be used.

(6) Both Sides of the Trunnion:
Besides damage during blowing, the surfaces on both sides of the trunnion lack protective layer coverage and are not easy to repair. Therefore, the carbon in the lining material easily oxidizes, causing severe damage. High-grade magnesia carbon bricks with excellent slag resistance and strong oxidation resistance should be used.

(7) Hearth and Bottom of the Furnace :
These parts are severely eroded by molten steel during blowing, but compared to other parts, the damage rate is lower. Magnesia carbon bricks with low carbon content can be selected, or tar dolomite bricks can be used. When high-speed blowing is used and the molten pool is shallow, damage to the center of the furnace bottom may be severe. Additionally, when bottom blowing is used, damage to these parts may worsen, so materials identical to those on the furnace belly charging side should be used.