The production process of Magnesia spinel brick

The production process of Magnesia spinel brick

1. Mixing of Magnesia spinel brick
It is carried out in a wheel rolling machine or a sand mixer, and the order of feeding is: granular material → pulp waste liquid → fine powder, and the total mixing time is not less than 10 min. Since the amount of CaO in the raw material is limited and the sintering degree of magnesia is increased, the trapping process is generally eliminated.
2. Forming of Magnesia spinel brick
Sintered magnesia is a barren material, and the green body has a low moisture content. Generally, there will be no over-pressure waste produced by gas compression. Therefore, high-pressure molding can be used to make the green body density above 2.95 g/cm3. This helps to improve the performance of refractory bricks.
3. Drying of Magnesia spinel brick
During the drying process of the green body, the physical and chemical changes that occur include the evaporation of water and the hydration of magnesia. The initial stage of water removal requires higher temperature, but high temperature will accelerate the hydration of magnesia and crack the green body.

4. Firing of Magnesia spinel brick
The firing of Magnesia spinel brick can be carried out in an inverted flame kiln or a tunnel kiln. Their load softening temperature is low, and the strength of the green body is low after the binder loses its effect. Therefore, the brick stack should not be too high, generally around 0.8 m. Since the physical and chemical changes that occur during the calcination of materials have been basically completed during the calcination of raw materials, the main mineral composition of refractory bricks can be considered to be basically the same as that of sintered magnesite, except that the degree of reaction close to equilibrium and the uniformity of mineral composition distribution are Improved.