In kilns, castables are now often employed. Refractory castables' service life is significantly impacted by their construction procedure. Among the many varieties of unshaped refractories materials, the manufacturing of castables is one of the more straightforward ones. Both the construction and the material utilization rate are moderately straightforward. It can extend the service life with proper use.
1. Baking of refractory castables
To improve the castable's physical qualities, baking is done to get rid of extra water, make sure that the free water and crystal water may discharge completely, and prevent "peeling and bursting" during the first feeding or use.
2. Water in castable structures
The secret to ensuring the strength of refractory castables is controlling the amount of water injected. Materials are often mixed using a forced mixer. After it has been thoroughly dry-mixed, add about 80% water and stir until the fluidity satisfies the vibration criteria.
3. Time for stirring
The quantity of water added during building has a direct impact on the castable's mixing time. Before adding water, whisk the dry mixture thoroughly for a minimum of three to five minutes. The better the castable's fluidity, the longer the mixing period.
4. Utilizing castables
The refractory castables must be consumed within 30 minutes, and they must be utilized in full buckets and bags. It should be used as soon as possible in the high temperature and dry working environment, and the castable that has originally set or even agglomerated cannot be reused.
5. Improve construction quality
In order to prevent pollution of refractory materials, the working environment needs to be kept clean before construction, and no debris should be mixed in, and construction tools and equipment should also be kept clean. Before and after construction, during the construction process, the construction instructions must be followed, and each link must be checked and accepted.
6. Reasonable temperature control
Due to the poor thermal stability of castables, severe temperature changes can easily damage the structure, and repeated drastic changes in temperature can cause thermal fatigue of castables. Controlling the temperature during use can easily extend the refractory castables service life.
7. Castables maintenance
The purpose of curing is to give the type of binder in the castable enough time to solidify and harden so that refractory castables can achieve the necessary initial strength. It is possible to say that curing can provide the binder enough time to solidify and harden so that it has a sufficient starting strength.
