What are the requirements of the performances of brasque refractory?
Physical properties of refractory include structural properties, thermal properties, mechanical properties, usability and operation property. The selection of the brasque refractory must have the following characteristics: 1. properties of not distortion and not melting at sufficient temperatures 2. have the necessary structural strength at high temperatures and does not soften and deform 3. must keep stable volume at high temperatures and will notcrack caused by expansion and contraction 4. will not rapture and flake when temperature is drasticly changed or heated unevenly 5. resistant to chemical erosion of metallic solution, slag and furnace gas, etc.
It is a kind of inorganic non-metallic material whose refractoriness is not lower than 1580 ℃. Refractoriness is the centigrade?temperature of refractory cone specimen wiyhout any load resisting high temperatures without melting down But only refractoriness can not fully describe the refractories, 1580 ℃ is not absolute. Refractory is now defined as material of physical and chemical properties allowing to be used in high temperature environments. Refractory is widely used in industries like metallurgy, chemical, petroleum, machinery manufacturing, silicates, power, etc., which is mostly used in the metallurgical industry, accounting for 50% to 60% of total output.
The requirements of the performances of brasque refractory: 1, should have sufficient refractoriness and softening point under a fixed load. Because under the action of the electric arc, the inner and surface temperature of the different parts of the brasque can be up to 1500 ~ 1800 ℃. 2, should have strong slag resistance. Because the inward permeation of slag and smoke at high temperature through its pores of brasque cause melting loss of refractories, organization delamination and flaking. 3, should have good thermal shock resistance. Because in the steelmaking process, opening the furnace door, lifting the furnace lid will cause sudden temperature change of brasque refractory,flaking and cracking, resulting in premature failure of brasque. 4, should have sufficient strength, because the brasque will be impacted at the time of loading, vibrated when tilting, flushed by metal, slag and gas flow when boiling. 5, the thermal conductivity and the conductivity should be small. Refractories commonly used for electric furnace include magnesia bricks, dolomite brick, high-alumina refractory bricks, silicious refractory brick and magnesite ramming material. Due to the different working environment of each parts of the furnace, refractories are different.
Physical properties of refractories include structural property, thermal property, mechanical property, usability and operation property. Structural properties of refractories include porosity, bulk density, water absorption, air permeability, pore size distribution,etc.. Refractory thermal properties include thermal conductivity, thermal expansion coefficient, specific heat, heat capacity, thermal diffusivity, thermal emissivity. Mechanical properties of refractories include compression strength, tensile strength, breaking strength, torsional strength, shear strength, impact strength, abrasion resistance, creep property, bonding strength, elasticity modulus. usabilities of refractories include refractoriness, refractoriness under load, reheating linear change, thermal shock resistance, slag resistance, acid resistance, alkali resistance, water resistance, corrosion resistance to CO, conductivity, oxidation resistance, etc.. Operation properties of refractory include consistence, slump, fluidity, plasticity, cohesiveness, resilience, coagulability and hardenability,etc. I hope you can solve the problem with my answer.
