The reason for the slow solidification of refractory castable in winter?
Refractory castable is a mixture composed of refractory aggregates, powders and binders, etc., which is usually used in high-temperature equipment such as furnace linings, pipelines, converters and other industries in metallurgy, electric power, petrochemical and other industries. In winter, the solidification rate of refractory castable slows down, which brings certain difficulties to construction and production. In this article, the reasons and solutions for the slow solidification of refractory castables in winter will be discussed.
1. Temperature influence.
Temperature is one of the important factors affecting the solidification rate of refractory castables. At low temperatures, the solidification rate of the material slows down due to the reduced rate of chemical reactions inside the material at low temperatures. In addition, when the ambient temperature is below 0, water freezing can also affect the fluidity of the material, further slowing down the solidification rate.
Second, the mix ratio design.
The unreasonable design of the mix ratio of refractory castable is also one of the reasons for the slow solidification in winter. If the ratio of powder and aggregate is not appropriate, or the type and amount of binder are not suitable, it will affect the fluidity, operability and strength of the material, and then affect the solidification rate.
3. The effect of admixtures.
In order to improve some properties of refractory castables, it is often necessary to add some admixtures to its mixture, such as coagulants, retarders, etc. If the admixture is not selected properly or the amount is not appropriate, it can also lead to a slower coagulation rate. Especially in winter, the effect of the admixture may be affected due to the lower ambient temperature, which in turn can affect the coagulation rate.
Fourth, construction factors.
During the construction of refractory castables, if they are not handled properly or the environmental conditions are poor, they can also cause their solidification rate to slow down. For example, construction problems such as uneven mixing, excessive water addition, and insufficient vibration may lead to an increase in the porosity inside the material, reducing the strength and fluidity of the material, and then affecting the solidification rate.
In view of the above problems, the following measures can be taken to improve the solidification rate of refractory castables in winter:
1. Reasonable selection of materials.
Choosing a refractory casable material suitable for winter use is the key to increasing its solidification rate. It is necessary to select raw materials with stable quality and reliable performance, and configure them according to a reasonable mix ratio. At the same time, it is also possible to consider using some additives with the effects of coagulation and early strength to improve the solidification speed of the material.
2. Improve construction conditions.
During the construction in winter, the construction of refractory castable should be selected indoors as much as possible to avoid the impact of low temperature on the material. At the same time, it is necessary to ensure that the humidity and temperature of the construction site are properly controlled to facilitate the curing of materials. In addition, the skill level of construction personnel should also be improved to ensure the standardization and accuracy of construction operations.
3. Adopt heating and curing measures.
Heat curing is an effective method to improve the solidification rate of refractory castables. By setting up a heating device at the construction site, the refractory castable can be kept at a certain temperature during the curing process to speed up the solidification rate of the material. However, it should be noted that the temperature and humidity should be controlled during the heating and curing process to avoid quality problems such as cracks.
In short, improving the solidification rate of refractory castables in winter needs to start from many aspects, including material selection, mix design, use of admixtures, and improvement of construction conditions. Only by comprehensively considering and taking corresponding measures can we effectively solve the problem of slow solidification in winter.