Since the year our company entered into the refractory industry, till now, we have about 20 years experiences in this field, and never stopped.
We appointed National refractory association and Luoyang refractory well-known expert as our technical consultant, the main managers in different divisions of the company are all have the corresponding senior or middle titles to service our customers. And we established technology R &D center for new refractory products’ research.
Our factory actively response to government environmental protection policy, we designed and built the fully automatic controlled high temperature gas tunnel kiln (1700℃), and got capacity of annual output 70,000 tons of high quality refractory products.
There are many factors to be considered when you choose the firebricks for your kiln, the most suitable bricks not only can improve the kiln service life but also save your money.
1. It depends on your kiln. The kiln can be divided into new masonry kiln and old kiln maintenance masonry. If the new one, we should know which parts,using temperature, special environment (acid alkali, high pressure,impact, wear and so on) of the firebricks to be used? Then choose the most suitable firebricks. If maintenance for old kiln , it can be based on experiences use of firebricks before, considering whether to use another materials instead, or improving and enhance the firebricks index.
2. According to the use part and working temperature or other speciications such as the cold crushing strength, the porosity, the creep rate, the linear change etc to choose and produce the firebricks to saticefy the production requirements.
3. The proportion of the standard brick and special shaped brick is determined. For example, standard brick is easy to purchase. If the special brick, needs customized mold and mass production, it's a high accurate require to the mold, also express richness and technological experiences of the factory.
(1) The compressive strength of castable precast blocks is high.
This performance is about 2 times higher than that of the conventional product.
(2) The thermal shock resistance is good.
The thermal shock resistance of castable precast blocks can be improved by 8 to 10 times.
(3) Excellent wear resistance.
The performance of CFB lining materials should have the following requirements:
1. The inner circulation vortex type turbulent bed lining requires high wear resistance, high temperature resistance and erosion resistance;
2. The lining of the inlet section of the high temperature external circulation separator requires high wear resistance and high temperature resistance;
3. The inlet of the medium temperature external circulation separator requires high wear resistance and high temperature resistance;
4. Medium and high temperature external circulation separator cylinders require heat resistance, heat insulation and low thermal inertia;
5. Ignition combustor flue requires high heat resistance;
6. The suspension chamber requires high heat resistance, wear resistance and low thermal inertia.
1. High refractoriness, the refractoriness of aluminium silicate refractory plastic can reach to 1750~1850℃ ,exceed the clay bricks which can be used directly in contact with the flame.
2. Good resistance to shock cold and heat, it won’t be peel when the temperature changes dramatically. The service life of refractory plastic is longer for half year than refractory bricks.
3. Good insulating performance. The thermal conductivity of refractory plastic is smaller than brick, therefore, less heat loss, it can reduce fuel consumption.
4. Good resistance to slag. It can resist the erosion of oxide slag, and the slag is not easy to bond, easy to remove.
5. The anti-shock and wear resistance performance are good. The column used for binding the bottom water cooling pipe and walking beam furnace is not easy to fall off and damage.
6. The masonry is compact.
Causes of damage to refractory bricks used in blast furnace lining:
1. Mechanical reasons in the blast furnace smelting process.
2. Chemical corrosion such as the reaction between the alkali metal oxide and the refractory brick.
3. High temperature action of the blast furnace itself.
4. In addition, due to the unreasonable design and construction of the furnace wall of the blast furnace itself, for example, poor quality refractory materials, unreasonable operation during the production process etc.
Methods for repairing blast furnace lining
There is a great relationship between the fluidity of the unshaped castable and the proportion of the castable trace agent and the material selection, it’s not significant with the ratio of the aggregate. In general, the fluidity of the castable should be considered from the properties of itself first, which is divided into acid, neutral ,alkaline, weak acid, weak alkali and so on. It can greatly improved the fluidity of the castable if add a certain amount of silica fume reduce using amount of the cement and greatly increase strength of the castable, but we all know that most of the silica fume is used as industrial secondary product, because of the quality stablity is not good,it may affect the overall usability of the castable.
Firstly weigh the refractory aggregates, powders, binders and admixtures, and dry-mix for one minute;
Secondly add water and wet mixing, and evenly spread the steel fibers into the material, and do not clump;
Finally mix for one minute can be discharged.
The total mixing time must not be less than 5 minutes. When the vibrating rod is used for molding, the vibration direction should be staggered to make the distribution of the steel fiber reasonable, which can improve the performance.