Refractory ramming material is an important refractory material. The following is a detailed introduction to it:
1. Definition and composition
Refractory ramming material is composed of refractory aggregate and powder, binder or other admixtures, etc., which are mixed in proportion and constructed by ramming method. Its performance is better than that of refractory concrete formed by vibration of the same material, but lower than or equivalent to unfired bricks. Refractory ramming material generally refers to dry ramming material, which has various types such as clay, high alumina, mullite, corundum, silica, magnesium, silicon carbide, mullite corundum, etc.
2. Characteristics
Hot hardness: Refractory ramming material has a high operating temperature, generally between 1450~1700℃, and can withstand thermal stress in high temperature environment.
Stripping resistance: After ramming construction, refractory ramming material has high density and strength, and is not easy to peel off.
Abrasion resistance: Ramming material has good chemical stability, erosion resistance, and can resist erosion and wear of molten materials.
Corrosion resistance: Refractory ramming materials have high volume stability and corrosion resistance, and can resist the erosion of high-temperature molten materials.
3. Application
Refractory ramming materials are widely used in manufacturing industries such as metallurgy, building materials, non-ferrous metal smelting, chemical industry, and machinery. For example, it can be used to fill the gap between furnace cooling equipment and masonry or masonry leveling layer, and can also be used in equipment that melts metals such as medium frequency furnaces and induction furnaces.
4. Construction points
Material selection: Finished materials produced by specialized manufacturers should be selected, and they should have factory certificates and instructions for use.
Particle size matching: The particle size of the ramming material should be evenly matched, and the ratio of coarse, medium and fine particles is roughly 4:2:4, and the maximum particle size is between 5 and 7 mm.
Construction temperature: The appropriate temperature should be controlled during construction to avoid excessively high or low temperatures affecting the construction effect.
Ramming method: Use a pneumatic hammer to ram continuously and evenly until the number of reciprocating times of the specified bulk density is reached. When ramming, it should be carried out from the center of the furnace to the surroundings to avoid the oil from squeezing to the center to form a soft spot.
Maintenance and drying: After the construction is completed, proper maintenance and drying should be carried out to ensure the strength and stability of the refractory ramming material.
V. Common problems and solutions
Low thermal conductivity: Some refractory ramming materials (such as carbon ramming materials) have low thermal conductivity, which is not conducive to the rapid cooling of the blast furnace body. The solution is to add admixtures to the ramming materials or change the local material use structure to improve its thermal conductivity.
Difficult construction: The construction of refractory ramming materials requires certain technology and experience, and requires high quality of construction personnel. The solution is to strengthen the training and management of construction personnel and improve their construction skills and level.
Refractory ramming material is an important refractory material with excellent performance and broad application prospects. In construction, it is necessary to pay attention to the key points such as material selection, particle size matching, construction temperature, ramming method, maintenance and drying to ensure the construction quality and the use effect of refractory ramming materials.
HOME