Mullite Bricks Introduction
The mullite brick is a refractory product made of synthetic mullite as a raw material with mullite as the main phase. When the Al2o3 content of mullite refractory brick is lower than the theoretical composition of mullite, there is a small amount of cristobalite,mullite brick contains a small amount of corundum when the Al2o3 content is higher than the theoretical composition of mullite. The high temperature creep of mullite brick is superior to that of high alumina bricks produced from natural bauxite materials. Mullite refractory bricks have high temperature performance is comparable to that of siliceous and magnesia products, refractory mullite brick have resistance to acid and low alkali slag ,which is better than magnesium.
Mullite Brick Features
1.Mullite fire bricks have high purity and low impurity content.
2.Mullite refractory bricks have low thermal conductivity, low heat fusion.
3.Mullite bricks have high dimensional accuracy and arbitrarily cut.
4.Mullite fire brick has high strength and excellent thermal shock resistance.
5.Mullite brick has high temperature resistance, direct contact with flame, resistant to various atmospheres.
Mullite Brick Specification
Index
Item |
|
Mullite bricks |
| Al2O3 |
(%) ≥ |
70 |
| Bulk Density |
(g/cm3) ≥ |
2.6 |
| Apparent Porosity |
(%)≤
|
18 |
| Cold Crushing Strength |
(Mpa) ≥ |
90 |
| Thermal Shock Resistance (1000 ℃,water,quenching,cycle) |
≥ |
25 |
| 0.2Mpa Refractoriness Under Load |
℃≤
|
1500 |
| Thermal conductivity |
(700 ℃)w/m.k≤
|
1.5 |
| Mix using Temp |
℃ ≥ |
1550 |
| Refractoriness |
℃ ≥ |
1790 |
| Wear - resisting Degree |
≤
|
8 |
Mullite Brick Application
1.Mullite brick are used in hot stove top
2.Mullite brick are used in oil cracking system dead angle lining
3.Mullite brick are used in blast furnace body and furnace bottom
4.Mullite brick are used in glass furnace regenerator & ceramic sintering kiln
Mullite brick Manufacturing Process
Mullite Brick Raw Material Selection
High alumina bauxite, iron bauxite, industrial alumina and clay as raw materials,which are made of mullite refractory bricks.The bauxite raw materials should be pre-fired to remove the structural water to avoid popping and splashing when the electric arc is concentrated and decomposed in the electric arc furnace.
Mullite Brick Ingredients
Correct selection of ingredients is an important process condition for producing the most mullite and fused phase products with less phasor and glass. In the actual ingredients, the actual control ratio of the aluminum silicon coefficient is lower than the theoretical value, and generally can be taken around 2.50.
Mullite Bricks Melting
The main equipment for melting is an electric arc furnace. Use fixed and tilt or three-phase electric arc furnaces.
Mullite Brick Pouring
The solution is injected into a certain shape and size of the structure, the structure is uniform, the casting model is to add a proper amount of binder to the quartz sand with higher purity, and the mixture is formed by drying.
Mullite Bricks Heat treatment
Divided into two stages of crystallization and annealing
Crystallization: for the casting of mullite refractory bricks, it is desirable that the mullite crystals in the product are fibrous or fine particles and evenly distributed. The main factor determining the particle size is the cooling rate.
Annealing: After the crystallization, the castings in the cooling process, due to the uneven heat dissipation of each part, there is a temperature gradient inside the casting, refeactory mullite bricks generates a large stress, which will cause cracks, ribs and corners. The greater the cooling rate, the greater the tendency for waste to occur, so the casting must be slowly cooled.
6 .Mullite brick Machining
Since the shape of the model of mullite fire brick is not accurate enough, the upper and lower shrinkages are inconsistent during the casting, and the shrinkage cavities, as well as the nozzle and the surface wrinkles, mullite refractory bricks are required to be processed. However, the casting has a high hardness and is difficult to process.
RS Refractory Feactory Provide Mullite brick Competitive Price
RongSheng refractory factory has been engaged in refractory material industry for more than 20 years.We have a big technological team, there are more than 15 senior designers for the furnace & kiln.They are good at different technological field, for exam, refractory bricks , castable refractory material, lightweight insulation firebricks and prefabricated bricks according to client requirement .
RongSheng refractory bricks factroy can provide specification and category as well as competitive price & high-grade quality refractory mullite bricks products.
