What causes the damage to the furnace lining?

Furnace lining is suitable for coreless intermediate frequency induction furnaces in iron and steel plants, foundries and metal manufacturing. High temperature resistant lining materials need to be supplied when the furnace is fired. The main raw material of the material belongs to the quartz matrix, and its chemical properties are acidic. It is based on the high-purity microcrystalline quartz matrix. Adding part of fused silica, high temperature-resistant binder, anti-quick cooling and fast-heating stabilizer, anti-seepage agent, anti-cracking agent, and imported composite micro-powder material has the disadvantage of improving the expansion of the furnace lining, and there is no crack when the furnace is cooled.

Cause of damage:

1, molten iron infiltration damage

The molten iron penetrates into the interior of the carbon brick along the pores of the carbon brick, and the soaked molten iron dissolves the binder in the carbon brick, thereby dissolving the carbon particles in the carbon brick, destroying the compactness of the carbon brick, reducing the strength of the carbon brick, and entering the carbon brick. The molten iron in the brick reacts with the carbon brick to form a brittle substance such as FexC-, which will cause volume expansion in the pores of the carbon brick in the future, making the pores of the carbon brick embrittled and cracked. A brittle layer is formed.

2, the circulation of molten iron in the furnace

The circulation of molten iron aggravates the erosion and erosion of the brittle layer on the surface of the carbon brick by molten iron, which makes the carbon brick thinner. The bricks are strongly eroded by the flowing slag iron, thus reducing the life of the furnace lining.

3. Corrosion of carbon bricks by alkali metals and zinc

The thermodynamic calculation shows that when the heat transfer performance of the carbon brick is poor, there is a large temperature difference between the hot surface and the ice surface, and the thermal stress of the temperature difference inside the carbon brick is large, which induces cracks in the carbon brick, and pure alkali metal vapor passes through the carbon brick. The microcracks of the carbon brick continue to flow and spread to the low temperature area of ​​the carbon brick, and the microcrack is the cause of the ring crack. If the alkali metal vapor enters the microcrack of the carbon brick, when the temperature reaches 800 degrees Celsius, the alkali metal vapor will be in the microcrack. Liquefaction, and then react with the silica-alumina ash of the carbon brick, causing the volume of the ash to expand by 30%, aggravating the expansion of micro-cracks in the carbon brick and forming cracks. The calculation shows that only after the alkali metal vapor is enriched and liquefied, it can work with CO. Activated carbon deposits are formed in the cracks. This reaction continues, and the cracks of the carbon bricks are continuously expanded and squeezed, and the cracks of the carbon bricks continue to expand, thereby splitting the carbon bricks to form ring cracks. Improving the thermal conductivity of carbon bricks is to prevent ring cracks. effective method.

The above is the analysis of the damage to the furnace lining

Luoyang Quantong Kiln Industry Co., Ltd. is a comprehensive high-tech company integrating development, production, sales and construction services. It is a high-tech enterprise in Henan Province and an IS09001 quality assurance system certification enterprise.