Coke oven is the basic equipment of coking plant. It is a kind of thermal equipment with complex structure and continuous production. As mentioned above, the coke oven is composed of carbonization chamber, combustion chamber, regenerator, furnace top, chute, small flue and foundation. 6557t refractory bricks are required to build a 42 hole 58- Ⅱ coke oven, including 4352t silicon bricks, accounting for 66.4%. During the operation period of 20-25 years, most of the brickwork of the coke oven is not easy to be hot repaired. Therefore, the refractory for furnace building must be able to meet the requirements of coking production process and achieve durability and reliability. The characteristics of jix coking production have their own basic requirements for refractory materials for furnace building. Different parts of the coke oven body bear different tasks, temperatures, structural loads, mechanical damage and medium erosion, so the refractory materials used in each part should have different properties.
The partition wall between the carbonization chamber and the combustion chamber, during normal production, the temperature of the main fire path can be up to more than 1550 ℃. The wall is the carrier to transfer the heat required for coking, which requires that the furnace building materials should have good high-temperature thermal conductivity; The partition wall also bears the structural load of the upper masonry and the gravity of the coal charging car on the furnace top, which requires that the furnace building materials should have the performance of no deformation under high temperature load; The wall surface of the carbonization chamber is eroded by ash, slag, moisture and acid gas, methane also penetrates into the gap of the brick to produce carbon deposition, and the bottom of the main fire passage is eroded by coal dust and dirt, which requires that the furnace building materials should have high-temperature corrosion resistance; During coal loading, the wall temperature of the carbonization chamber drops sharply from about 1100 ℃ to 600 ~ 700 ℃, so the furnace building materials are required to have the performance of resisting high temperature upheaval above 600 ℃; Due to the influence of coke pushing, the bottom brick of the carbonization chamber is also required to have high wear resistance.
The temperature difference between the inner and outer walls of the combustion chamber furnace head is wide, and the temperature changes greatly during coal loading. At the same time, it is also affected by the pressure of the protective plate, which requires that the furnace building materials should have good resistance to temperature upheaval and good pressure resistance.
The temperature difference between the upper and lower layers of the lattice bricks used in the regenerator is about 1000 ℃, and the temperature difference between the updraft and downdraft is between 300 ~ 400 ℃, which requires that the lattice brick material should have the characteristics of large bulk density and strong resistance to temperature upheaval.
The temperature of the small flue is lower than 100 ℃ in the rising gas flow and higher than 300 ℃ in the falling gas flow. The brick gas duct is affected by the normal temperature gas and water vapor. Therefore, both require that the furnace building materials should have the performance of resisting temperature upheaval below 300 ℃.
In a word, the refractory for building coke oven should have the following characteristics: the softening temperature under load is higher than the maximum temperature of the used part; It has the ability to resist temperature upheaval within the temperature change range of the use part; It can resist the erosion of various media that may be encountered in the use part; Carbonization chamber combustion chamber has good thermal conductivity, lattice brick has good thermal storage performance and so on. The refractoriness, thermal conductivity, thermal expansion, porosity, bulk density, high-temperature load softening temperature, high-temperature volume stability, temperature change resistance, etc. of common refractories should meet the requirements.