Application of Dry Sludge in Refractory for Blast Furnace

blast furnace refractory

Blast furnace refractories are often used stemming, commonly used is a water cannabis mud, but when the steel production is high, this iron mouth stem mud is more susceptible to mechanical scouring and chemical erosion of slag iron, resulting in blast furnace slag Not a net, not only affect the smooth and high yield blast furnace, but also prone to iron in the refractory brick process of iron off, leading to runway accidents caused by heavy run. At the same time as Tietou tide, prone to playing Tietou "rocket" burns and other accidents.
The main production of anhydrous stemming ingredients ratio (%): Brown Iron Jade 15-24, 6-15 silicon carbide, coke 20, lime 12-16, tar 18-20. The gun mud compressive strength of 20Mpa, open the mouth opening in the blast furnace refractory openings easy, and anti-erosion performance is better.
The key component of lime mud is too large, will cause mud shrinkage is too large, resulting in cracks, too small, affect the mud plasticity, in the amount of stemming on the basis of 12%, and gradually found in the burn line changes Is +0.3%, the best performance, high plasticity at the moment, when there is good micro-expansion at high temperature tapping, no cracks, effective from the no swelling, cracks caused by channeling iron, , The risk of burned stave in severe cases.
Key components of low, medium temperature sintering agent added in a large amount, will have an impact on the stability of the iron, sintering agent added to the stemming at low temperature to generate low-melt, so anti-erosion ability of stemming deteriorated, splashing spatter . Found that when the ratio of 2.5%, when dealing with the iron mouth, than the water cannons save 25min time, and does not affect the trenches processing, tapping, the iron flow stability.
The above anhydrous mud in the domestic water heaters No. 1 and No. 2 blast furnace used, compared with the same period of water mud, blast furnace technical indicators are as follows: Tiekou pass rate increased by 2%, the punctuality rate rose 6.6%, iron content Poor pass rate rose 8%, iron mouth tapping wind rate decreased 96%, increase once a day tapping, blast furnace operation safety factor has also been improved. The development and application of this anhydrous stem mud has been extremely successful, contributing to the steady and high yield of refractories for blast furnaces.

Recent article:
How to Choose Refractory Bricks Used for Different Parts of Blast Furnace
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Analysis of the reasons of damaged blast furnace lining fire brick

blast furnace refractory lining material

1.Temperature.

The damaged performance of high temperature to fire brick:
(1)Erosion. When the edge air develops excessively, but the factory uses poor quality refractory material which has lower refractoriness under load, if the high temperature is over than allowable temperature, the fire lining brick will be eroded.
(2)Heat stress.
(3)Thermal shock. Thermal shock is a phenomenon when the fire brick meet the unsteady thermal stress and then become damaged.Cracks will occur in the refractory bricks and eventually broken.

2.Mechanical erosion and abrasion

3.Chemical attack

4.One of the important factors of firebrick refractory sale lining damage is unreasonable design, construct and furnace structure. Poor quality refractory and furance construction create the condition for the first kind of destructive factors.

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How to Choose Refractory Bricks Used for Different Parts of Blast Furnace

Refractory Brick

How to choose refractory brick used for different parts of blast furnace?
When choosing refractory brick used for different lining parts of blast furnace, we should follow some principles. The refractory lining of every part should fit the parts thermal current intensity, so that the lining can maintain previous vertebral shape and stability under the impact of strong heat flux.

Here are some methods of selecting refractory brick for every part of furnace lining.

(1) Furnace throat. It mainly needs to withstand impact and abrasion of burden, so generally we use steel brick or water cooling steel brick for the furnace throat.

(2) The upper shaft. Plus the burden descent and ascending gas flow of scour and wear. Therefore, we should choose resistance to chemical erosion and abrasion resistance of refractory material, the most appropriate is high relative density brick, high density, high aluminum brick or phosphoric acid impregnated clay brick.

(3) The middle and lower part of furnace and furnace bosh. The main mechanism of damage is thermal shock, high temperature gas scouring, and impact of alkali metals, zinc and carbon deposition, as well as chemical erosion of the initial slag. For those three parts, we should choose refractory materials with properties of thermal shock resistance, slag erosion resistance and erosion prevention. For blast furnace whose volume is smaller than 1000m3, we can use aluminum carbon refractory bricks used in blast furnace.

(4) Furnace bosh. Hot gas erosion and iron slag erosion are the main reasons for furnace bosh damage, this part of the heat flux intensity, refractory material life not long (as long as 1 to 2 months, as short as 2 to 3 weeks), generally used in refractory degree is high, load softening temperature is high and the volume density of refractory material, such as the high aluminum brick, alumina carbon brick.

(5) Hearth tuber. This site is only in blast furnace of oxidation reaction area, high temperature from 1900 to 2400 DEG C, lining by damage caused by high temperature thermal stress. Composite brick masonry hearth tuyere zone is adopted by the modern blast furnace, material for high alumina, corundum Mo mullite; corundum and silicon nitride combined silicon carbide, useful also hot pressed carbon block.

(6) The lower part and bottom of hearth. For those two parts, we use hot pressing small carbon brick, micro porous carbon brick, and hot semi graphite carbon brick with high thermal conductivity, good resistance to penetration, good resistance to chemical erosion, low porosity and micro aperture, as well as brown corundum or gray corundum brick used for ceramic cup.


Article source:
How to Choose Refractory Bricks Used for Different Parts of Blast Furnace

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The difference between anti-peeling high-alumina brick and ordinary high-alumina brick

Refractories are widely used in metallurgy, building materials, chemicals, petrochemicals and machinery manufacturing and other industrial areas, play an active role in the national economy. However, the application of refractories in high-temperature furnace evaluation, in addition to improving the service life, lower kiln energy consumption, it should also contain refractories in the production process of their own energy-saving, that is selected in the production of low-temperature firing, the product has the appropriate Of the high-temperature characteristics and low thermal conductivity.

Compared with the traditional high alumina brick, the thermal shock resistance is high, the strength is high, the chemical resistance is low, the coefficient of thermal expansion is low, the thermal conductivity is low, the firing temperature is low, and the material function is greatly improved. Consumption.

From the following aspects to clarify the problem:

First, the lower firing temperature 150 ~ C. Because of high temperature firing and insulation, especially in the greater than 1450 ℃ after the refractory refractory energy consumption can be infinite, according to the present refractory brick high-alumina brick 300,000 t / a count, estimated savings of 50,000 tons of standard coal.

Second, compared with the traditional high-alumina bricks, anti-shedding high-alumina brick thermal conductivity value of the former 2/3, or even lower, compared with magnesium chrome brick, as long as 1/3 ~ 2/3. Anti-shedding high-alumina brick and adjacent alkaline brick, lower carcass surface temperature 75-98 ℃, preliminary accounting can save nearly 2000t / a standard coal. Saving effect, considerable economic benefits.

Third, the traditional high-alumina brick can not enter the large-scale dry kiln, due to the use of life is too low, repair, stop kiln frequently form considerable energy loss and economic losses. More noteworthy is that it can not overcome the inherent weaknesses in the use of harsh locations.

Fourth, the world today with the rapid development of industry, to the formation of the Earth's environmental pollution infinite economic losses, the serious problems of human health has been more and more people's attention. In order to make a long life, we must take into account the material itself can not be a source of pollution. The excellent function of anti-shedding high-alumina bricks can largely replace the magnesia-chrome bricks. Magnesia-chrome brick in the course of processing and waste brick processing will bring serious "chromium pollution", its scientific component is carcinogenic substances. In Europe and the United States has gradually abandoned the production and use of this material, and quickly developed in the development of chromium-free goods, and anti-shedding high alumina brick is an excellent alternative.

The anti-drop high alumina brick is successfully used in the relevant parts of the cement kiln and used in the large-scale float glass kiln regenerator, instead of the traditional magnesia chrome brick, not only prolongs the kiln service life, but also eliminates the chromium pollution. In addition, the anti-shedding high-alumina brick firing temperature than magnesium-chrome brick low about 300 ℃, energy-saving effect is considerable.

Anti-shedding high-alumina brick as a versatile and efficient new energy-efficient refractory material, the American Ceramic Society magazine will be informed of this material as "the development of a potential by China's new high-alumina refractories." Anti-shedding high-alumina brick in the metallurgical and building materials industry has a wide range of applications.

Anti-peeling high-alumina brick and the difference between ordinary high-alumina brick

Refractories are widely used in metallurgy, building materials, chemicals, petrochemicals and machinery manufacturing and other industrial areas, play an active role in the national economy. However, the application of refractory in high-temperature furnace evaluation, in addition to improving the service life, lower kiln energy consumption, it should also contain refractories in the production process of their own energy-saving, that is selected in the production of low-temperature firing, the product has the appropriate Of the high-temperature characteristics and low thermal conductivity.
In this case,
Compared with the traditional high alumina brick, the thermal shock resistance is high, the strength is high, the chemical resistance is low, the coefficient of thermal expansion is low, the thermal conductivity is low, the firing temperature is low, and the material function is greatly improved. Consumption.
In this case,
From the following aspects to clarify the problem.
In this case,
First, the lower firing temperature 150 ~ C. Because of high temperature firing and insulation, especially in greater than.

Submerged Entry Nozzle---Refractory Nozzle

Submerged entry nozzle enjoys performances of purifying liquid steel, prevent liquid steel oxidation, with good liquid steel washing resistance and erosion resistance.

Submerged Entry Nozzle

Introduction

Changxing Refractory's submerged entry nozzle is isostatically pressed from alumina-graphite with zirconia inserts and magnesia seats as required. Argon channels are also available. These pieces are 100% X-ray tested for flaws and cracks prior to shipment. These submerged entry nozzles are engineered to provide maximum life at minimal cost.
Advantages

1. The Submerged Entry Nozzle (SEN) and Submerged Entry Shroud (SES) protect the steel flow from the Tundish to the mould.
2. Submerged Entry Nozzle is fixed inside the Tundish and also functions as a Tundish Nozzle. Submerged Entry Shroud on the other hand is fitted from the outside on the Tundish Nozzle.
3. The body is made of Alumina Carbon quality while the seat and slag zone are made of different qualities as per customer requirements including Zirconiz-Carbon and Magnesia Carbon quality.
4. The SEN and the SES are protected from the outside with a ceramic paper lining.
5. Submerged entry nozzle is served to protect and control the molten steel stream between the tundish and the mould during casting.
Application

Submerged entry nozzle enjoys performances of purifying liquid steel, prevent liquid steel oxidation, with good liquid steel washing resistance and erosion resistance.

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Refractory plastics for heating furnaces

Furnace is used to bloom blanks, continuous casting billet, small steel ingot, slab heating to the required temperature of the thermal equipment.
The furnace body components of the furnace mainly include furnace top, furnace wall, furnace bottom, discharge end and feeding end, slope slipping, front wall brackets, slippery and curved slide rails, , The bottom of the water pipes, chute pipes, flues and chimneys, stove and steel structure and so on, in addition to a combustion device, air supply systems, heat exchangers, push steel and so on.

Furnace temperature is generally below 1400 ° C, for continuous and ring furnace, it can be divided into low temperature, medium temperature, high temperature, or preheating, heating and soaking section, the use of temperature Respectively, 800-900 ° C / 1150-1400 ° C / 1200-1300 ° C.

Refractory plastic is a longer time in a high plasticity was hard mud paste-like unshaped refractory material, it is a certain level of the refractory aggregate, fine powder, the right amount of binder, plasticizer, save Agent and water.
In recent years, China's large and medium-sized steel enterprises in the rolling mill furnace top, wall lining work on the overall use or part of the use of refractory plastic can provide the service life of the furnace, and achieved good economic returns.

Refractory company Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory brick, refractory castable,refractory nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.

Analysis on Performance Requirement of Refractory material in Heat Treatment Furnace

The qualified of anchor brick is similar to the material of furnace lining castables and formed by preeing and being fired at high temperature. Characterized by good thermal shock resistance and high strength, it is used for several heating furnace and has good effect.

Refractory: Any material capable of resisting high temperatures and capable of withstanding high temperature physical and chemical effects.
Heat treatment furnace refractory material performance requirements:
1 has sufficient refractoriness. Refers to the refractory material after heating to a certain degree of softening temperature, but not its melting point.
According to the level of refractoriness, ladle refractory can be divided into ordinary refractories (refractory degree of 1580 ~ 1700 ℃), advanced refractories (refractory degree of 1770 ~ 2000 ℃) and special refractories (refractoriness greater than 2000 ℃).
2 has a certain high temperature structural strength. The structural strength at high temperature is evaluated by the softening point of the load, and the softening point of the load is the pattern
(The size of φ36 * 50mm) under a certain pressure (0.2MPa) conditions, a certain heating rate of heating, measured the sample began to deformation (deformation of the original sample 0.6%) temperature, the temperature is called refractory castable Of the load softening point starting point.
3 high temperature chemical stability.
4 has good resistance to abrupt heat.
5 volume stability at high temperatures.

Technical Innovation of Carbon Brick for Blast Furnace Hearths

Carbon Brick for Blast Furnace Hearths

Possessing with the excellent corrosion resistance and high thermal conductivity which can lead to easily form a protective layer for blast furnace hearth, refractory brick carbon bricks have been used as refractory material for hearths for more than half century.

To further improve its performance, the refractory experts have carried out many investigations recently. Finally, they find out some main reasons which caused the damage. They are including as below:
1) The penetration of molten iron into pores.
2) Erosion due to direct contact with molten iron (dis-solution by carburizing).
3) Embrittlement of the material on hot side (loss of cooling capacity).

In order to enhance its corrosion resistance, the experts have developed new technology to get new magnesia carbon brick through numerous experiments.
1) Add the aluminum oxide which has a good resistance to molten steel.
2) Reduce the pore diameter to prevent the penetration of molten steel and other impurity items.
3) Enhance the high thermal conductivity to reduce the surface temperature.
4) Add the TiC to improve the corrosion against molten steel, increase its viscosity and slow down the flow which could effectively reduce the damage on the MgO-C bricks.

Article sources:

http://www.yilongrefractory.com/news/Technical%20Innovation%20of%20Carbon%20Brick%20for%20Blast%20Furnace%20Hearths.html