Why do high-alumina refractory bricks return to alkali and become white?

Alkali return is actually a problem of hoarfrost on the surface of high-alumina refractory bricks. During the firing process, due to factors such as technology and raw materials, the brick body will produce certain pores, so there will be a certain water absorption rate. Soluble salts, along with moisture, transfer to the surface of the brick, forming what we call hoarfrost.

Why do high-alumina refractory bricks return to alkali and become white?

1. The cement used in construction should be Portland cement produced by regular manufacturers, and slag cement produced by informal manufacturers must not be used. We found that if Portland cement produced by regular manufacturers is used, there will be almost no white frost on the brick surface. If slag cement is used, the white frost on the brick surface will be more serious!

2. Seawater is used in the construction of high-alumina refractory bricks. The salt contained in seawater will also cause hoarfrost on the brick surface. The sand used for construction should be river sand and avoid using sea sand.

3. Before laying high-alumina refractory bricks, the cushion layer should be laid as soon as possible. The advantage of this is that the alkali in the cement cushion will be released in advance before paving, so that there will not be a lot of weathering on the surface of the high-alumina refractory bricks after paving.

4. During the construction process, workers must pay attention to the cleanliness of the brick surface. The brick surface of high alumina refractory bricks should be cleaned and covered with fine sand when paving.