How are silicon bricks used in coke ovens?

The core principle of using silicon bricks in coke ovens is to leverage their high-temperature stability, sensitivity to rapid heating and cooling, and susceptibility to moisture and alkali. The core approach is “precise construction + rigorous oven drying + stable operation and maintenance.” Specific methods are as follows, with the entire process controlled within specifications.

First, pre-use preparation: Silicon bricks must undergo rigorous acceptance testing to ensure SiO₂ ≥ 93%, load softening temperature ≥ 1620℃, and dimensional deviation ≤ ±1mm. Products from the same manufacturer and batch should be used for the same coke oven. Storage must be rainproof and moisture-proof. Before construction, the moisture content should be checked and found to be ≤ 1%. Damp bricks should be dried before use. The construction environment must be kept dry.

Construction uses a double-sided mortar application method, using silicon refractory mortar of the same material. Mortar joints should be controlled at 4±0.5mm, with a fullness rate ≥ 98%. Dry construction is strictly prohibited. Expansion joints must be reserved, with 2mm per meter along the length of the oven to prevent brick damage under high temperatures. Special-shaped silicon bricks are used in the core areas for a bonding structure.

Oven drying is a critical step, requiring a slow temperature increase, taking 15-20 days to reach 1100℃ from room temperature. Excessive temperature differences must be avoided to prevent brick cracking; the heating rate must strictly adhere to specifications. During operation, the furnace temperature should be maintained stable between 1100-1350℃, avoiding rapid heating and cooling to prevent silicon brick peeling.

Routine maintenance requires regular inspection of the bricks, timely repair of damaged areas, and avoiding contact with alkaline media. Direct washing of the high-temperature bricks with water is strictly prohibited. Silicon bricks are mainly used in high-temperature areas such as the carbonization chamber walls, combustion chamber, and furnace roof. Appropriate brick types should be selected according to the specific location to ensure long-term stable operation of the coke oven.