A lightweight castable

Abstract

The invention provides a light-weight casting material. The light-weight casting material is prepared by mixing raw materials including 10 to 50 percent of rod-shaped aggregate, 0 to 45 percent of light-weight aggregate, 4 to 10 percent of silicon ash with the granularity less than or equal to 0.2mu m, 17 to 30 percent of bauxite cement, 8 to 20 percent of floating microspheres, 5 to 10 percent ofclosed-pore pearlite, 0 to 10 percent of high alumina bauxite powder and a water reducing agent. According to the light-weight casting material provided by the invention, the small-size rod-shaped aggregate is uniformly dispersed so that the firing after-shrinkage of a product is reduced, the thermal shock resistance of the casting material is remarkably improved and the service life is greatly prolonged; different amounts of the light-weight aggregate which is continuously graded are added, so that the casting material has high strength and good flowability and casting materials with different thermal conductivity coefficients can be prepared, and furthermore, an application range of the casting material is expanded.

Description

technical field [0001] The invention belongs to the technical field of refractory materials and relates to a lightweight castable, in particular to a lightweight castable with rod-shaped aggregates as aggregates. [0002] technical background [0003] The so-called lightweight refractory castable is made of lightweight refractory aggregate and powder, binder and admixture. The performance of lightweight aggregate has a direct impact on the performance of castable. Lightweight castable is a kind of unshaped refractory material with high temperature resistance, low bulk density and low thermal conductivity. It has many advantages of refractory castable and lightweight refractory at the same time, and it has attracted more and more attention in high temperature industry. Lightweight castables have low volume density, large apparent porosity, low thermal conductivity, good heat insulation performance, greatly reduce heat loss, and improve the efficiency of thermal equipment; seco...

AI Technical Summary

Problems solved by technology

[0005] At present, the commonly used methods for preparing aggregates for lightweight castables include extrusion molding, casting molding, etc.; in these preparation methods, small-sized aggregate particles of specific shapes cannot be prepared, and aggregate particles with large sizes cannot be prepared. Qualified lightweight castables, therefore, under the conditions of the existing preparation methods, it is impossible to prepare aggregates with excellent performance and specific morphology and lightweight castables with excellent performance

In addition, the aggregate particles prepared during the machine press molding preparation process are relatively large (blocks with a minimum diameter of 20-30mm), and in order to obtain particles with smaller particle sizes, it is necessary to crush the prepared large particles after firing. The morphology of the particles cannot be controlled during the crushing process, and the particles obtained by crushing are very uneven and contain many edges and corners; and in the preparation process of casting molding, it is difficult to form aggregates with too small size, and it is difficult to form aggregates in casting molding. In the process, separate molds are required to be formed one by one, which requires a large amount of water, low body strength, and easy damage when demoulding after preparation and forming, resulting in low pass rate of finished products and waste of mold raw materials and product raw materials; produced by molds one by one The entire production process is also intermittent, and continuous production cannot be achieved. Generally, a set of molds can only be used once. During the intermittent production process, the mold must be replaced continuously, which not only greatly increases the production cost of the mold, but also makes it difficult to realize automatic production. , It needs to be manually disassembled and arranged. The installation and replacement time of the mold in the whole preparation process is much longer than the preparation time of the aggregate sample. It is time-consuming, laborious, high production cost, and it is difficult to realize automatic continuous production.

[0006] The aggregates prepared by the above method include shale ceramsite, clay ceramsite, expanded perlite, red leaf waste, corundum hollow balls, etc.; the air in the mixture cannot be excluded during the preparation process of the above method, so that the prepared aggregate The porosity is large, which reduces the strength, and the strength of the castable prepared with the above aggregate is also low, and the amount of water added when the above aggregate is used to prepare the castable further reduces its strength; in addition, the castable prepared with the above aggregate Lightweight castables have high impurity content and are not resistant to high temperatures. Liquid phase firing is prone to occur in high temperature environments, resulting in severe volume shrinkage, which seriously reduces the service life of lightweight castables and affects their use. Moreover, the prepared castables are thermally stable. Poor performance, easy to crack and peel off during use

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