Power plant boilers mainly include pulverized coal boilers and circulating fluidized bed (CFB) boilers. Different areas of the boiler are exposed to different temperatures, abrasion, erosion and thermal shock conditions, so suitable refractory castables should be selected according to the actual operating environment.

1. Slag-Resistant Wear-Resistant Castable

This castable provides high strength, excellent abrasion resistance, erosion resistance and slag resistance.

Applications: Boiler furnaces, slag coolers and areas exposed to severe abrasion, erosion and slag attack.

2. Steel Fiber Wear-Resistant Castable

Steel fibers are added to improve mechanical strength, impact resistance and thermal shock resistance, providing better resistance to spalling.

Applications: Coal feeding openings, slag coolers, furnace areas, superheaters and cyclone separator inlets.

3. Wear-Resistant Self-Flowing Castable

Self-flowing castables have excellent flowability and can fill complicated structures and narrow areas with minimal vibration.

Applications: Membrane walls, inertial separators, corners and areas where vibration casting is difficult.

4. Thermal Shock Resistant Castable

This type of castable provides high refractoriness, strength and thermal shock resistance, making it suitable for areas with frequent temperature fluctuations.

Applications: Ignition air ducts, water-cooled air chambers and other areas subject to rapid temperature changes.

5. High-Strength High-Alumina Castable

High-alumina castables offer high strength, abrasion resistance, impact resistance, penetration resistance and corrosion resistance.

Applications: Boiler arches, roofs, rear walls and other high-temperature areas.

6. Corundum-Mullite Wear-Resistant Castable

Based mainly on corundum and mullite, this castable provides high strength, excellent wear resistance, high-temperature performance and good thermal shock resistance.

Applications: Boiler furnaces and other high-temperature, highly abrasive areas.

Common Application Areas

Refractory linings in CFB boilers are exposed to intense particle circulation and abrasion. Common application areas include:

• Boiler furnace and dense-phase zone

• Coal feeding openings

• Return feeders

• Cyclone separators

• Slag coolers

• Ignition air ducts

• Water-cooled air chambers

• Boiler roofs and walls

• Superheaters and other highly erosive areas

Selection Considerations

Refractory castables should not be selected based only on service temperature. Abrasion, erosion, thermal shock, slag corrosion, construction method and equipment structure should also be considered.

For CFB boilers, particular attention should be paid to abrasion resistance, high-temperature strength, thermal shock resistance and erosion resistance.