When using silicon brick for coke oven, the following matters should be paid attention to to to ensure its performance and service life:

I. Dimensional accuracy and processing requirements

Dimensional deviation: the dimensional deviation of silicon bricks for coke ovens in all directions should be controlled within ±1.5mm, and it should be limited to 1 mm for special bricks (such as adjusting bricks). This helps to ensure the accuracy and integrity of masonry.

Surface quality: no cracks with a width greater than 0.5mm are allowed on the surface of the product. Silicon bricks should be processed in advance to avoid a lot of processing in the construction site, so as to reduce the quality problems caused by improper processing.

II. Temperature control

Oven-drying process: In the oven-drying process, the maximum expansion of silicon brick occurs between 100~300℃, and the expansion before 300℃ is about 70%~75% of the total expansion. Therefore, the heating rate should be strictly controlled when drying the furnace to avoid cracks caused by excessive expansion of the brick due to rapid heating.

Working temperature: when the working temperature is lower than 600~700℃, the volume of silicon brick changes greatly, and the performance of resisting rapid cooling and rapid heating is poor. Therefore, when the coke oven works at this temperature for a long time, the masonry is easy to break and be damaged. It is suggested to avoid being in a low temperature state for a long time during design and operation.

III. Masonry quality requirements

Mud plumpness: When building coke ovens, the mortar squeezing method should be adopted on both sides to ensure that the mud is full and tight. The mud plumpness of vertical joints should not be less than 95%, and all refractory joints should be pointed to ensure the air tightness and structural strength of masonry.

Smoothness and verticality: the smoothness and verticality of masonry surface should be checked and controlled at any time, and the problems should be corrected in time. After the mud in masonry dries up, it is not allowed to correct its quality defects by knocking.

IV. Material Selection and Performance Requirements

True density: The smaller the true density of silicon brick, the more complete the Shi Ying transformation and the smaller the residual expansion. Generally, the true density should be below 2.38 g/cm, and the high-quality silicon brick should be below 2.35 g/cm.

Thermal shock resistance: Silicon brick has good thermal shock resistance above 600℃. However, due to its poor thermal shock resistance, materials with better thermal shock resistance (such as clay bricks, high alumina bricks, etc.) should be selected in parts with large temperature fluctuations (such as furnace heads).

V. Treatment of special parts

Furnace head: Because the temperature at the furnace head fluctuates greatly, which usually exceeds the limit of 573℃ where the volume of silicon brick is stable, silicon brick cannot be used, but clay brick and high alumina brick with good thermal shock resistance should be selected.

Carbonization chamber and combustion chamber: The working layers of carbonization chamber and combustion chamber need to be built with dense silicon bricks to improve thermal conductivity and corrosion resistance. The furnace ends at both ends of the carbonization chamber are generally built with clay bricks because of the drastic temperature change.

VI. Maintenance and inspection

Regular inspection: In the process of use, the surface and internal conditions of silicon bricks should be inspected regularly, and problems such as cracks and peeling should be found and treated in time.

Cleaning and maintenance: during the masonry process, the masonry should be kept clean to avoid impurities and dust affecting the masonry quality.

By strictly following the above precautions, the service life of silicon brick for coke oven can be effectively extended and the stable operation of coke oven can be ensured.