How to Extend the Service Life of Castables

The service life of refractory castables is affected by many factors. In addition to strictly following the construction standards during construction, curing, and baking after construction is completed is also very important. Good early maintenance is essential to extend the service life. Today, the editor will take you to understand how to extend the service life of refractory castables from seven aspects.

1. Maintenance of refractory castables

Maintenance is one of the important factors affecting the performance and service life of castables, and it is also one of the reasons that is easily overlooked. Maintenance is to provide sufficient initial strength to the binder in the castable to obtain sufficient initial strength. The maintenance time is related to the type of binder of the castable. It can be said that maintenance can give the bonding agent time to solidify and harden to obtain sufficient initial strength.

2. Baking refractory castables

Baking is to eliminate excess moisture, maintain and bake according to standards, promote the sintering process at high temperatures, and further improve the physical properties of the cast body. Therefore, refractory castable materials must be baked before use. The baking should meet the baking system to ensure that the free and crystal water in the casting material can be fully discharged. Do not “peel or burst” during feeding or early use to affect the normal use of the pouring material. Baking is a direct and critical factor that affects the performance of refractory castable materials.

3. Construction moisture of refractory castables

Ensuring the strength of refractory castables is the key to controlling the amount of water added. When mixing, a forced mixer is generally used, to dry and mix evenly, then add about 80% water and mix until the fluidity meets the vibration requirements.

4. Use of refractory castables

The castable must be used in the entire bucket, and the mixed castable is generally used up within 30 minutes. In high temperatures and dry working environments, it should be used as soon as possible. Castables that have initially been set or even agglomerated should not be poured into the mold, nor should they be mixed with water for reuse.

5. Refractory castable mixing time

The mixing time of castables is closely related to the amount of water added during the construction process. Generally, the mixing time is required to be controlled at 3 to 5 minutes. Under the premise of the same amount of water added, the longer the mixing time, the better the fluidity of the castable. Good castable curing, baking, moisture, and mixing time control can extend the service life of the castable.

6. Improve construction quality

To prevent the contamination of refractory materials, the working environment must be kept clean before construction, and construction tools and equipment must also be kept clean. During the construction process before and after construction, the manufacturer should be required to operate according to the construction instructions, no random construction is allowed, and each link must be inspected and accepted.

7. Reasonable temperature control

Due to the poor thermal stability of castables, drastic temperature changes can easily damage the structure and repeated drastic temperature changes can lead to thermal fatigue of castables. As long as we want to control the temperature, we can easily extend its service life.