Clay Fire Bricks for Tunnel Kiln Introduction
Clay fire bricks are acidic refractory products, which increase with the increase of Si2o3 content. They have certain corrosion resistance to acid slag and poor resistance to alkaline slag erosion. Therefore, refractory clay bricks should be used as the lining of acid kiln. . Also used in high temperature furnaces such as blast furnace, hot blast stove, glass kiln, carbon co-firing furnace. There are have high quality used fire clay bricks for sale in Rongsheng.
Clay Fire Bricks for Tunnel Kiln Features
(1) Chemical and Mineral Composition.
The content of AL2O3 is 30%~48%, the content of SIO2 is 50%~65%, and a small amount of alkali metal, alkaline earth metal oxide Tio2, Fe2o3 and the like. The mineral composition is generally: mullite, cristobalite and quartz, glass phase
(2)Fired Clay Bricks Refractoriness
The degree of refractoriness is generally from 1580 to 1750 °C. As the Al2o3/Sio2 increases, the refractoriness of the product decreases significantly when the content of low-melt impurities is high.
(3)Refractory Clay Bricks Load Softening Temperature
The load softening temperature is about 1250~1450 ℃, the range of variation is wide. The starting deformation temperature is lower, the difference from the 40% deformation temperature is about 200~250°C.
(4) Clay Fire Bricks Linear Expansion Coefficien
The linear expansion coefficient is low, and the average linear expansion coefficient of 20~1000°C is 4.5~6*10-6 /°C. Refractory clay bricks thermal conductivity is also low.
(5) Clay Refractory Bricks Thermal Shock Resistance
The thermal shock resistance is good and the fluctuation range is large. The 1100 ° C water cooling cycle is generally greater than 10 times. This is related to the low coefficient of linear expansion of clay products, the inconspicuous effect of crystal transformation and the plasticity at high temperatures.
(6)Fire Clay Bricks Strong Resistance to Chemical
Strong resistance to chemical attack: Because clay refractory bricks is weakly acidic, fire clay bricks for sales has strong resistance to acid slag erosion and weak resistance to alkaline material erosion.
Clay Bricks for Tunnel Kiln Specification
Brands
Item
|
Clay Bricks |
| ZGN-42 |
GN-42 |
LZ-55 |
| Al2O3（%） |
42 |
42 |
55 |
| Bulk Density（g/cm3） |
2.3 |
2.2 |
2.4 |
| Apparent Porosity(%) |
15 |
16 |
23 |
| Refractoriness(℃） |
1750 |
1750 |
1760 |
| Permanent Liner Change（1500℃*2h）% |
0~0.2 |
0~0.2 |
0~0.2 |
| Cold Crushing Strength(Mpa) |
58.8 |
49 |
49 |
| 0.2Mpa Refractoriness(℃） |
1430 |
1450 |
1430 |
Clay Fire Bricks for Tunnel Kiln Application
1. Clay fire bricks used in high temperature furnaces
2. Clay fire bricks used in blast furnace
3. Clay fire bricks used in hot blast stove
4. Clay fire bricks used in glass kiln
5. Clay fire bricks used in carbon co-firing furnace
Clay Bricks for Tunnel Kiln Manufacturing process
1.Refractory Clay bricks Preparation of Clay Clinker
Clay clinker acts as a skeleton in clay bricks. Clay clinker is calcined from hard clay in a rotary kiln. The clinker requirements for clinker are stable chemical composition, impurity content not exceeding the standard, good sintering, water absorption between 2% and 4%, and true density above 2.7g/cm3.
2.Refractory Clay Bricks Clay Brick Binder Selection
The basic requirements for bonding clay: high plasticity, low sinterability and high fire resistance. Semi-soft clay or soft clay is usually used as a blending compound with soft clay.
3.Refractory Clay Bricks Preparation of Mud
The ratio of clinker to bonded clay should be determined by the quality requirements of the product, the shape and size of the brick and the molding method of the brick. High quality requirements, clinker accounted for more than 80%, even 90%
4. Refractory Clay Bricks Characteristics
High quality refractory products with correct dimensions, high density and high strength. For some special shaped products, the molding performance is required to be good. Generally, the amount of clay combined is 25%~30%, sometimes up to 40%. For some refractory products, in order to reduce the firing shrinkage, the shape is good, and the amount of clinker is appropriately increased in the ingredients.
The composition of clay products is generally composed of coarse and fine particles and less medium particles, which not only ensures the compactness and strength of the refractory products, but also improves the thermal shock resistance of the refractory products. The particle size of the particles should also be adjusted and corrected according to size and surface quality requirements.
5.Refractory Clay Bricks Drying and Firing
❉RS factory refractory bricks are generally formed by semi-dry molding. The water content of the billet is low. If the firing kiln has a drying section. Fired clay bricks is impossible to dry in advance and directly into the kiln.
❉For specific and large and hand-formed bricks, due to the difficulty of moisture removal, to prevent over-speed cracking, generally according to the single weight and shape complexity of the brick, fired clay bricks is dried in the air for about one week and then sent to the dryer.
❉The greater the amount of clay used, the lower the Al2o3 content in the clay. The higher the impurity content, the more intense the reaction, the volume shrinkage and uneven heating, and the greater the internal stress, the more likely the brick will crack during the firing stage.
Clay Bricks for Tunnel Kiln Firing Stage
1. Fired clay bricks normal temperature to 200 ° C. At this time, the temperature should not be too fast to prevent cracking.
2. Fired clay bricks medium temperature stage (200 ° C ~ 900 ° C). This stage of heating should speed up, in order to facilitate the chemical reaction of organic matter and impurities in the brick.
3. Fired clay bricks 900 ° C to the highest firing temperature: the temperature should be stable at the high temperature stage, continue to maintain the oxidizing atmosphere, so that the body is evenly heated, but also to prevent cracking.
5. Fired clay bricks cooling stage. According to the lattice change of the product in the cooling section, the temperature should be rapidly lowered in the high temperature stage above 800~1000 °C, and below 800 °C, the cooling rate should be slowed down.
Fire Clay Bricks for Tunnel Kiln Manufacturer in Rongsheng Refractory Factory
RongSheng Refractory have rich refractory raw materials and 20 years experienced in the refractory bricks manufacturing.Rongsheng factory as one of fire clay bricks manufacturer can provide specification and category as well as competitive price & high-grade quality refractory clay bricks products.
