Since the performance of refractory bricks is different from other bricks, there are some special considerations when laying bricks:
1. The joints of refractory bricks shall be filled with grout, and the width of brick joints shall meet the design requirements of the drawings. The brick joints between refractory bricks not only provide a channel for the infiltration and erosion of high-temperature molten slag under operating conditions, but the slag erosion itself also promotes the continuous enlargement of the brick joints. These two effects both increase the contact surface between the slag and the side of the refractory brick, and make the refractory brick suffer excessive stress on the side of the brick during each cycle of shrinkage and expansion caused by heat. The slag not only erodes the furnace brick along the radial direction but also along the circumferential direction of the brick. Especially when there are circumferential cracks on the side of refractory bricks, the circumferential erosion rate is faster, causing blocky spalling on the surface of the bricks. Therefore, brick circumferential cracks have greater influence and effect on brick life than radial cracks.
In actual masonry, the principle of refractory brick masonry should be met in order to meet the industry masonry requirements of refractory materials. Brick joints should be full during masonry, mortar should be squeezed out of the joints, no void joints are allowed, and mortar should not be poured into the mortar joints. The fullness of the mortar should be greater than 95%.
2. After placing each brick, hit it with a wooden hammer or a rubber hammer to squeeze out more than the fire mud. Make sure that the shells of the brick joints are completely tight, and the bricks should be in surface contact and firmly bonded. When beating, it is necessary to prevent unsuitable beating or squeezing from damaging the refractory bricks or damaging the fire mud that has begun to solidify. Silica brick masonry is 12~13mm; magnesia refractory brick masonry is 10~14mm; clay brick masonry is 5~6mm; high alumina refractory brick masonry is 7~8mm; corundum refractory brick masonry is 9~10mm; Lightweight viscous refractory brick masonry is 5~6mm.
3. Excess fire clay should be scraped off before the fire clay in the brick joints is completely hardened. If some places need to be filled with fire clay, a scraper should be used to plug the new fire clay, that is, the masonry joints. The masonry must be jointed once every time it reaches 0.5m high, and then it can be built upward, and the jointing shall be smooth. When building special-shaped refractory bricks in the calcining chamber, the masonry should not exceed four layers and should be carefully jointed once. Thick mud should be used when jointing to ensure the tightness of the masonry.
4. the mortar joint should be horizontal and vertical, the arc surface is flat, and the joints are tight. It should be ensured that the masonry is consistent with the ruler pair indicated by each equipment. In the process of masonry, the external surface jointing should be carefully and carefully, and it is necessary to ensure that the appearance is straight and smooth. The thickness of the brick joints of the masonry shall be checked with a feeler gauge. The width of the feeler gauge is 15mm, and the thickness is equal to the thickness of the checked brick joint. If a feeler gauge conforming to the thickness of the designed brick joint is used, when the rib is inserted, the depth does not exceed 20mm, it is qualified.
5. Straight walls shall be constructed with staggered joints, and the vault and kiln shall be constructed with straight joints in the direction of the circumferential belt. The masonry adaptability strives to make the brick joints straight and smooth. The geometry of the masonry should meet the requirements of the drawings to ensure the quality.
6. Metal components such as brick slabs and flanges should not be in direct contact with refractory bricks. Fire-filling mud should be applied to the components, and about 10mm expansion joints should be left under the brick slabs. Refractory fiber felt can be stuffed into the expansion joint to protect the brick supporting board. Flanges and metal parts can be sealed with autumn mud to avoid contact between metal parts and high-temperature gas.
7. From the construction to the production process, the masonry should be prevented from being damp and frozen, and the temperature should be prevented from being too high prematurely, so that the refractory mud cannot reach the proper strength.
When building refractory bricks, the masonry plan should also be adjusted appropriately according to different specifications and models, so as to be able to adapt to the construction requirements.
