Extending the service life of refractory bricks needs to start from many aspects such as material selection, construction, operation management and maintenance. The following are some specific measures:

I. Reasonable selection of materials

Selection of refractory bricks according to working conditions: Select suitable refractory brick materials according to the service environment (such as temperature, chemical corrosion, mechanical wear, etc.). For example, in high temperature environment, high alumina brick or corundum brick with high alumina content should be selected; In acidic corrosive environment, silicon brick or zircon brick can be selected; In alkaline environment, magnesia brick or magnesia-chrome brick is more suitable.

Choose high-quality refractory bricks: choose high-density refractory bricks with low porosity to ensure their impermeability and thermal shock resistance.

II. Optimize the construction

Structural design:

Avoid stress concentration and reserve expansion joints (usually 5~10mm/m) to prevent thermal expansion from causing cracking.

Staggered masonry is adopted to enhance the overall stability.

Construction technology:

Use special refractory slurry to ensure that the bond strength matches the brick body.

Strictly control the thickness of mortar joint (generally ≤2mm or less) to avoid weak points.

Avoid barbaric construction and prevent brick body from being damaged.

III. Oven Drying and Temperature Control

Sectional oven drying: operate strictly according to the heating curve to avoid cracking caused by rapid cooling and heating. For example, free water is removed below 100℃, crystal water is removed at 300~600℃, and the temperature is gradually raised to the working temperature above 600℃.

Stop cooling: naturally cool down and avoid forced ventilation cooling.

IV. Maintenance during use

Temperature management:

Avoid long-term over-temperature operation (such as exceeding the softening temperature of refractory bricks by more than 10%).

Reduce frequent shutdown, temperature fluctuation will accelerate thermal fatigue.

Chemical protection:

Avoid slag, molten metal or gas (such as CO, SO) directly eroding the brick body, which can be isolated by coating or baffle.

Mechanical protection:

Reduce material impact (such as adding wear-resistant lining or buffer layer).

Regularly clean up the accumulated slag to prevent local overheating or chemical erosion.

V. Regular maintenance and repair

Inspection period: once every 3~6 months, focusing on the observation of cracks, peeling and erosion.

Partial repair:

Small-scale damage can be repaired with refractory castable or paint spraying.

Bricks need to be replaced for large-scale damage to avoid "running with disease".

VI. Other Precautions

Avoid moisture infiltration: keep dry when stopping the furnace to prevent the brick from powdering due to water vapor condensation.

Matching materials: anchors, insulation layers, etc. should match the thermal expansion coefficient of refractory bricks.

Case reference

Cement rotary kiln: using magnesia-alumina spinel brick and reasonable oven, the service life can be extended to over 12 months.

Ladle lining: by adding impermeable coating, the corrosion of molten steel is reduced and the service life is increased by 30%~50%.

Through the above comprehensive measures, the service life of refractory bricks can be significantly prolonged, thus reducing the replacement frequency and cost.