Alkali-resistant castables are divided into ceramic alkali-resistant castables and high-voltage electromagnetics, that is, alkali-resistant castables and high-strength alkali-resistant castables.

Alkali-resistant castables are used in preheater systems, precalciners, rising flues and tertiary air ducts of cement kilns and preheaters in lime kilns.

 

Alkali-resistant castables are alkali-resistant hydraulic castables prepared from silico-alumina materials, aluminate cement as binder, and a certain proportion of admixtures. When the alkali-resistant castable is in contact with alkali vapor, a dense glaze layer can be formed on the surface under high temperature conditions, which can prevent the alkali erosion from deepening, thereby improving the service life of the kiln lining.

 

Cement and silica micropowder are the main raw materials of alkali-resistant castables, and the addition amount has a great influence on the normal temperature and high temperature properties of the material.

 

The addition of calcium aluminate cement is increased by reducing the 200-mesh fine powder of building ceramics. Under the condition of a certain amount of silica micropowder, the increase in the amount of cement will generate more hydration products and play a binding role. , and also filled the pores of the alkali-resistant castable.

 

The surface of the high-strength alkali-resistant castable contains certain glaze components. These glaze components have a lower melting temperature and are more likely to form a liquid phase during the sintering process. On the other hand, the liquid phase is mainly formed on the surface of the aggregate particles and in the matrix, which increases the bonding performance between the matrix and the aggregate. Attention must be paid to strengthening the aggregate and matrix integration effect of the castable. , to avoid the toughness of the castable at room temperature. Especially for castables such internal unevenness must be avoided.

 

In order to improve the density of alkali-resistant castables. Silicon micropowder has the function of filling and promoting sintering. When used together with a suitable dispersant, only a small amount of water can be added to make the castable have better rheology and improve the high temperature strength of the alkali-resistant castable.