Reasons for The Decrease in Strength of Refractory Castables

In the application process of refractory materials, the problem of reduced strength of refractory castables is often encountered. So, what causes the decrease in the strength of refractory castables? This article will conduct a comprehensive and detailed analysis of this and propose corresponding solutions.

1. Quality issues of refractory castables

Refractory castables are mainly composed of refractory aggregates, powders, and binders. If there are quality problems with the raw materials, the hardness and strength of the refractory castables will be affected. To ensure the quality of raw materials, we can select high-quality suppliers and conduct appropriate quality testing and screening.

2. Improper construction of refractory castables

Improper addition of water causes a decrease in the strength of castables: Refractory castables are usually supplied in a bag. Usually, after arriving at the site, construction workers have to add water for mixing before use. However, the amount of water added is usually very important. Excessive water addition If the amount is too small, the raw materials cannot be fully integrated. Adding too much water will cause the aggregate and powder to separate and deposit, causing the refractory cast components or linings to produce more pores due to the escape of a large amount of water during the drying process, making them The structure is loose and the strength is reduced. Therefore, we must add water according to the proportion during use. At the same time, during the water-adding process, we must use a mixer to stir evenly before construction can begin.

Improper mixing mechanism causes a decrease in strength: Mixing is mainly completed in fixed mixing equipment at a constant speed. It is mainly divided into three stages to break the agglomerates of dry powder and homogenize the powder particles; add water to the powder, To transform it from dry powder to a fluid state, this process requires sufficient mixing energy, which is usually called the turning point of refractory castables; after adding the required water, mix the material to a suitable stable state and homogeneity state. The mixing force, mixing uniformity force generated during the mixing process, and the increase in temperature of the refractory castable slurry will all affect the strength of the refractory castable. During the mixing process of powder, we must mix it according to a reasonable proportion.

3. Improper later maintenance of refractory castables

After the construction of the refractory castable is completed, it needs to be naturally dried and hardened. After that, it needs to be baked to remove the internal moisture and also preheat the furnace wall. If the baking process is not strictly carried out by the baking standards, it will be very difficult to It is easy to cause the lining to dry out, significantly enlarge the pores, and increase the permeability, which ultimately leads to a decrease in the strength of the refractory castable. Therefore, during the baking process, the heating and baking must be carried out according to the baking requirements.

4. Impact on the natural environment

The impact of the natural environment on refractory castables is mainly reflected in the decrease in temperature in winter, which will affect the drying and heating process of refractory castables, indirectly leading to a decrease in the strength of the final refractory castables.

The above are some reasons for the decrease in the strength of refractory castables. Generally speaking, the above four points are the more common ones. We only need to add water according to the specified amount during the construction process, standardize the operation process, and pay attention to changes in the natural environment. It can prevent the strength of refractory castables from decreasing.