Analysis on the Causes of the Damage of the Ferroalloy Furnace Body

Reasons and analysis of furnace damage

1. The electrode working end is too long for a long time, and the furnace bottom refractory material is consumed a lot, which causes the temperature of the furnace bottom to rise abnormally or the result of furnace bottom burning through.

2. The working end of the electrode is insufficient for a long time, the high temperature area moves upward, the temperature of the furnace wall near the electrode high temperature area rises abnormally, and the area around the tap hole of the furnace eye is burned throughthe iron leakage slag.

3. The slag type is unreasonable, the alkalinity control does not meet the requirements, and the molten iron is overheated seriously, causing chemical corrosion of the furnace body and damaging the refractory materials of the furnace body.

4. After the furnace is turned off for a long time, the furnace body is very prone to expansion and cracking. If the furnace is frequently started and stopped, it will be obvious that the furnace body steel plate will crack due to temperature changes, and it needs to be repaired in time.

5. The operation of oxygen blowing and opening eyes has great loss to the furnace eye and furnace wall. Whether it is carbon brick or magnesia brick, oxidation reaction can occur under high temperature conditions, and the formed false furnace wall cannot play a protective role, which greatly accelerates the furnace. Physical deterioration.

6. The furnace body leaks water and the material moisture exceeds the standard. Although part of it can evaporate after entering the furnace, the remaining part will decompose with high temperature and form oxygen, which will corrode the furnace wall.

7. Due to the corrosion that occurs when the temperature reaches the Thaiman temperature, the magnesia bricks of the working layer where the high-carbon ferrochromium contacts the slag are subjected to the chemical erosion and mechanical impact of the hot molten iron and the slag, and the composition and mineral composition of the magnesia bricks are changed. Although the reaction temperature is lower than the melting point, it begins to show diffusion.

Combining the above reasons, the main factors in terms of physics, chemistry, and machinery are summarized as follows:

1. Melting phenomenon: the working temperature of refractory material exceeds its refractoriness and corrosion will occur. Melting often occurs in the furnace wall near the arc zone and the furnace bottom at the electrode end. Through the analysis of the temperature measurement patch and thermocouple data of the furnace bottom, the temperature at the bottom of the furnace bottom electrode end is the highest, and if the electrode working end is too long, the furnace bottom temperature will rise significantly.

2. Chemical attack: The various chemical reactions between refractory materials and slag, molten metal, dust, exhaust gas and other substances are called chemical attack. The types of chemical attack include gas-solid reaction, liquid-solid, liquid-liquid reaction and gas-liquid reaction. When the working temperature of the refractory material approaches and exceeds its refractoriness, the chemical attack of the metal on the fire material becomes more prominent.

3. Mechanical action: In the working layer, the refractory material higher than the softening temperature of the load is very susceptible to the mechanical force of the metal and slag and is lost.

4. Spalling and cracking: Under the action of rapid cold and rapid heat or uneven heat load, the internal thermal stress of the refractory exceeds its structural strength and local damage occurs. After the furnace was shut down and opened for a long time, the furnace body expansion and cracking were particularly obvious, and such scenes can also be observed in the tap chute.