What steps are required for magnesia brick masonry

Magnesite brick is an alkaline refractory with magnesia content of more than 90% and periclase as the main crystalline phase. Generally, it can be divided into sintered magnesia brick (also known as fired magnesia brick) and chemically bonded magnesia brick (also known as unburned magnesia brick). Magnesia bricks with high purity and firing temperature are called directly bonded magnesia bricks because periclase grains are in direct contact; The brick made of fused magnesia is called fused and bonded magnesia brick. Generally, it can be divided into sintered magnesia brick (also known as fired magnesia brick) and chemically bonded magnesia brick (also known as unburned magnesia brick). Magnesia bricks with high purity and firing temperature are called directly bonded magnesia bricks because periclase grains are in direct contact; The brick made of fused magnesia is called fused and bonded magnesia brick.

Magnesia brick has high refractoriness, good alkali slag resistance, high load softening starting temperature, but poor thermal shock resistance. Sintered magnesia brick is made of magnesia brick, which is crushed, proportioned, mixed and shaped, and then fired at 1550~1600 ℃. The firing temperature of high-purity products is above 1750 ℃. The unfilled magnesia brick is made by mixing, molding and drying magnesia with appropriate chemical bond. Based on the experience of producing magnesia bricks, the magnesia brick company has made the following provisions for refractory brick masonry in order to give full play to the efficiency of kiln lining materials, ensure the service life of kiln lining materials and extend the service life:

1. Carefully clean the dust and slag on the inner wall of the kiln shell;

2. The kiln shell shall be flat without unevenness;

3. The mortar joint between magnesia bricks shall be controlled within 1.5mm~2mm;

4. The daubing of mastic shall be uniform and full without slurry shortage. Daub the mastic evenly, and rub the mastic with the masonry to make the mastic extrude slightly;

5. The masonry of kiln lining shall be flat without staggering, and common defects such as dislocation, inclination, uneven mortar joints, misalignment, double joints, through joints, opening, void, hairy joints, serpentine bends, masonry bulge and slurry mixing shall be avoided;

6. The expansion joint in the refractory brick lining must be reserved according to the design and shall not be omitted;

7. The lining of important parts and complicated parts of magnesia brick shall be pre built first;

8. The lock seam shall be firm. When processing refractory bricks, the bricks shall be finely processed by the brick cutter, and manual processing bricks shall not be used; The top sealing brick of magnesia brick in the rotary kiln and under the brick support plate shall not be less than 70% of the original brick; In the flat joint brick and bend brick, it shall not be less than 1/2 of the original brick. The opening must be locked with the original brick. The processing surface of the brick should not face the inner side of the furnace.