With the development of new dry-process cement production technology, the corresponding refractory materials have also made great progress. In addition to the conventional refractory bricks have a breakthrough, the performance of refractory castables is also more and more perfect, and widely used in the kiln in the amorphous parts. As we all know, refractory castable is a kind of amorphous refractory material without calcination, which is made of refractory aggregate, refractory powder and binder according to a certain proportion; construction by adding water and mixing with good mobility, and then by molding, maintenance (to be baked according to a certain temperature system) to make it condense, harden can be. The use of refractory castables is characterized as follows: First, the masonry structure has fewer joints, strong integrity, good sealing, the application of the operation can be avoided clinker powder infiltration; Second, it is easy to anchor and construction is convenient, which is conducive to improving the efficiency of masonry and masonry quality; Third, the raw material is taken from a wide range of materials, to facilitate the comprehensive utilization of resources, and the delivery time is short, and the amount of inventory can be reduced accordingly, and its related costs. Based on these advantages, refractory castables in the cement firing system in the application of the proportion of rising year by year to 5000t / d new dry kiln, for example, the use of refractory castables and refractory bricks has reached the proportion of 1:1.
1.Measures to accelerate the life cycle
A refractory castable is commonly known as a heat resistant concrete, and as such, it also conforms to the doctrine of concrete. Such as the amount of water is to control the refractory castable can realize the fundamental reason for the design strength. However, driven by the interests of some constructors in the construction of refractory castables, in order to speed up the construction progress in the casting material will be a large number of water, resulting in the construction of the kiln refractory lining in the use of the cycle is much lower than the design requirements, and even the use of half a year on the emergence of serious problems, it must be overhauled (and construction of good refractory castable, the use of 3 to 5 years do not need to be overhauled). We know that the refractory investment in the entire plant investment in a small proportion (about 2% a 4%), but its impact on the future operation of the entire system is very large. Because of the refractory lining material accident stop the loss of a day, as little as hundreds of thousands of yuan or even millions, so ensure that the high operating rate of the firing system, in order to realize the system’s high-quality, high-yield and low-cost operation.
2.The following steps are strictly enforced
(1) The amount of water added to the castables should be controlled in strict accordance with the instruction manual, and should not exceed the limited amount, and under the premise of guaranteeing the construction performance, the amount of water added should be less rather than more.
(2) The mixing time of the castables should not be less than 5min, and a forced mixer should be used for the operation. It is advisable to mix the castables dry first, then add 80% of water for mixing, and then depending on the degree of wetness and dryness of the castables, add the rest of water for mixing until a suitable working consistency is obtained.
(3) The pouring material poured into the mold frame should be immediately vibrated with vibrating rod in layers, the height of each layer should be not more than 300mm, and the vibration spacing should be 250mm. When vibrating, try to avoid touching the anchors, not to damage the insulation layer, and not to be vibrated and vibrated for a long time on the same part, and the vibrating rod should be slowly withdrawn after seeing the surface of the material returned to the pulp, so as to avoid segregation of the layer of the material and the appearance of cavities.
(4) When large area is poured, it should be constructed in pieces, and the area of each piece of pouring is about 1.5m², the expansion joint should be left according to the design, and should not be missed, and the expansion joint should be located in the middle of the interval of the anchoring pieces.
What is refractory cast material?
Refractory Casting: When used in partial denture casting procedures, it is a casting made of a material that can withstand high temperatures without decomposing; it is expansive and compensates for metal shrinkage. Refractory castings are made from investment materials.
What is castable in refractory?
Castable Refractory—A refractory mixture with heat resistant hydraulic cement and binders that can be cast in place. Castable refractory has many applications in industry as well as studio ceramics. It is often used in kiln construction because it is easy to use and mix, and reasonably priced.
What are castable materials?
Casting materials are usually metals or various time setting materials that cure after mixing two or more components together; examples are epoxy, concrete, plaster and clay. Casting is most often used for making complex shapes that would be otherwise difficult or uneconomical to make by other methods.