2017年7月28日星期五

Refractories for electric furnace roof

Refractories for electric furnace
Refractories for electric furnace
Electric furnace roof prefabricated with special high-alumina materials, fused corundum, chromium oxide and a variety of additives as the main refractory raw material, the prefabricated, dry and other processes from the production. With high temperature strength, anti-peeling performance and slag erosion performance, easy assembly, long service life. It is suitable for use in the top triangular area of the furnace and the working area of LF furnace.

Electric furnace cover with refractory brick require good thermal shock resistance, high temperature splash on the erosion resistance, as well as good integrity, solid structure is not crack and so on.

Electric furnace lid with refractory material development trend is: brick - prefabricated block - the overall pouring, the specific conditions of different countries, the use of materials are not the same.

For alkaline firebrick cover, electric tile with magnets. In order to ensure the stability of the furnace cover structure and reduce the deformation and peeling of magnesia, the use of iron plaster or masonry insert iron. As the metal induced current (especially high power electric furnace refractories cover), the formation of local overheating to non-magnetic steel brick, on the other hand pure magnesia brick linear expansion coefficient is too large, the amount of small.

In addition, the whole pouring the lid. The use of the overall casting furnace lid to promote the life of the furnace to further improve. After the water is cooled, the electrode is also water-cooled around the electrode, and the high-alumina ultra-low cement castable containing 3% Cr2O3 is added from the material and the stainless steel fiber is added. The furnace cover is used in the case of slightly repaired 594 furnace and service life is 4 times than before.

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Refractories for electric furnace roof

E-mail:sales8@chinaelong.com

Continuous smelting and repair of induction furnace

refractory material for induction furnace
refractory material for induction furnace
1.Continuous furnace
To reduce the repeated heat that caused by quenching furnace lining cracking, continuous smelting is very induction furnace refractory lining materials important for the extension of lining service life, it has caused attention of many users. If can not continuous use, intermediate frequency furnace in after a single use, want to join metals in furnace burden, and cover induction furnace lining material the furnace cover, it can not only give metal furnace material preheating, also can prevent the lining cracks caused by rapid cooling.

2.The Repair
(1) The intermediate frequency furnace Refractory company reach to 20 heats then need to tear down all of my throat opening, purpose is to check whether the furnace lining is drill iron, also check the dry lining loosening clearance. To repair the oven, it is best to use high metal front ring, and pay special attention to the old and new interface cleaned up. During the refractory brick next furnace operation, it should open first time below the fettling interface.
(2) The furnace mouth and throat opening is often slagging, impact erosion and burden, it need constant maintenance and repair, to ensure the normal dimensions of intermediate frequency furnace.

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Continuous smelting and repair of induction furnace

E-mail:sales8@chinaelong.com

2017年7月21日星期五

The Best Refractories for Induction Furnace -- 25+ Heats Silica Ramming Mass

Medium Frequency Induction Furnace Drying Tamp Mass
Neutral ramming mass is used for induction furnace lining with longer service life.

In recent years, silica ramming mass is widely used in induction furnace. Compared with traditional refractory lining materials, this product is of lower cost, shorter sintering time and better working condition.

To offer clients better refractory products, we have successfully developed our 25+ heats silica ramming mass. As per actual working, we summed up the refractory for sale material consumption as following. 1. First heat: 10-15mm 2. Rest heat: 3-5mm

As per our experience, we should leave 70mm as save level. So if the lining thickness is 180/300/450mm, we could promise the least service life of our refractory material to be 25 heats. If the working condition is convenient, 30-40 heats is no problem.

Furthermore, our refractory castable silica ramming mass can also be applied in tundish and ladle. Service life can namely be 48-60 hours/ 200+ heats.

Because of the great advantages as above, our silica ramming mass is very welcomed by our clients all over the world say Bangladesh, Ghana, South Africa, and Indonesia, etc. If more interests, please feel free to make us informed, our professional teams are ready to give you our reliable service. For new clients, we would offer more preferential as following. 1. Lower price trial order 2. Professional refractory technicians overseas service.

Therefore, what are you waiting for? Talk your phone and call us!

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The Best Refractories for Induction Furnace -- 25+ Heats Silica Ramming Mass

E-mail:sales8@chinaelong.com

Factors that affect the service life of induction furnace lining

Intermediate Frequency Induction Furnace Lining Material
This is acidic silica ramming mass premixed with H3BO3, widely used for the lining of Medium Frequency Induction Furnace of iron, steel, copper-aluminum and alloy industry, etc.
1.Lining thickness. As the thickness of lining goes up, the service life will be longer.
2.Tightness of lining. Normally we use puematic tamper for lining, some customers do lining manually, tightness of lining is not so good, so the service life is shorter.
3.Tapping temperature. High tapping temperature leads to short service life.
4.The sintering by the first heat is also critical for a good lining.
5.Scrape quality. If the quality of scrape is bad, it will cause more slag, which is bad for lining.
6.Scrape feeding method. Rough feeding will hurt the lining.
7.Melting time. Normally the melting time is around 1.5 hours, if longer, the service life will be shorter.
8.Try not to use iron scale for decarborization, it is very harmful for the furnace lining material.
9.Remaining thickness and ending frequency. Some customers has certain limits on this two factors, our recommendation is to listen to experienced workers.
10.Lining thickness at slag zone. Different steel plant has different working condition, so the slag zone is not the same, it is better to adjust the thickness at slag zone to increase the service life.
11.Melting better be continuous. If it is not, lining could be break by the force of thermal shock.

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Factors that affect the service life of induction furnace lining

E-mail:sales8@chinaelong.com

2017年7月11日星期二

Refractory materials for different parts of electric ARC furnace(2)

Magnesia Carbon Brick
In order to make balance the damage of the furnace wall and prolong the service life, furnace wall is also used inlaid water cooling box or water cooling measures. The inner surface of the furnace is sprayed with a layer of fire-resistant coating to make the dross form a protective layer, which can reduce the unit consumption of the refractory material. effectively. But the energy consumption is relatively increased.

(3) Refractories for bottom of electric ARC furnace
Knotted lining use good sintered magnesia or fused magnesia, there is working lining and permanent lining under the ramming layer.The working lining use tar pitch bonded magnesium refractory brick magnesia brick, and permanent lining is generally use magnesia brick. The slag line parts upper the dike slag line parts,as slag erosion is serious,now more use the lining brick what same or similar the furnace wall hot spots,such as casting magnesia-chrome brick or re-combination magnesia-chrome brick. The effect is better when use of magnesia carbon brick, the service life can be as high as 100 to 200 furnace times.

The anode end of the direct current electric arc furnace is connected with the contact piece of the furnace bottom, the bottom of furnace use thermal conductivity refractory material or metal components to solve the problem of conduction, the main requirements of the conductive refractory is low resistance (10-4 ~ 10-2 Omega . m) and the resistance must be stable, usually using combination asphalt with resin ,magnesia carbon bricks having a carbon content of preferably 10% to 18% are used as the conductive refractory, and include permanent lining, working lining and a protective coating. Working lining use magnesia ramming compound.

(4) Refractories for taphole
In 1980s, the advantages of tapping port are: The tilting electromechanical equipment has been canceled, the area of the water-cooling wall has been expanded, the damage of lining has been eased, the temperature of tapping steel can be reduced and the time of tapping can be reduced, thus reducing investment and saving electric energy. people use resin-bonded magnesia-carbon brick as taphole bricks, magnesia carbon refractory brick for sale as tube brick, and people use magnesia carbon brick or Al2O3-C-SiC brick as end brick. In order to make the melton steel flow out more successfully, usually people use olivine-based coarse sand as drainage material.

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Refractory materials for different parts of electric ARC furnace(2)

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Refractory materials for different parts of electric ARC furnace(1)

Refractory materials for electric ARC furnace
Refractory materials for different parts of electric ARC furnace
(1) Refractories for ARC furnace roof
Electric Arc Furnace life refers to the life of furnace roof. After the 1980s, with the expansion of steel-making electric arc furnace capacity and the increase of unit power, the working conditions of the furnace roof become more demanding, the refractories used for electric Arc furnace also changed.

The roof of arc furnace commonly use high alumina brick to masonry, Al2O3 content of between 75% to 85%. Compared with silica brick, the characterized of high alumina brick is high refractoriness, thermal shock resistance, good slag resistance, high compressive strength. Because of its high thermal shock resistance and structural integrity, it is not necessary to produce shaped bricks. There ie a rich bauxite resources in China, high alumina insulating brick has become the main refractory material on Arc Furnace roof, its life is 2 to 3 times of silica brick roof . With the development of large-scale ultra-high-power electric furnace, the service life of high-alumina brick is reduced, Leading to the further use of calcined or not burning magnesia brick and magnesia-chrome brick and other alkaline brick.

(2) Refractories for ARC furnace wall
The furnace wall is divided into general furnace wall, slag line area and hot spot that near the arc . The main furnace wall mainly uses the magnesia brick, the tar pitch combination and the asphalt impregnation burns the dolomite brick and the magnesite refractory brick masonry, also has uses does not burn the magnesia alkaline brick and the asphalt union magnesia and the dolomite ramming material, That all have longer service life. ARC furnace wall which Ultra-high power or smelting special steel used the magnesia-chrome brick and high-quality magnesia brick to masonry.

Slag line area and the hot spot of furnace wall is weak link. As the furnace wall life depends mainly on the degree of damage of hot spot, so the parts of lining should be special attention. the 20th century 70 years ago, the masonry of the site commonly used cast magnesium chrome bricks, combined with or re-combination of magnesia- chrome brick, the service life is 100 to 250 furnace times. Into the 80's, in these parts widely used magnesia carbon bricks
 to masonry, showing that in addition to high temperature and slag resistance performance,service life be significantly improved , the high-power electric arc furnace to more than 300 times in China.

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http://www.yilongrefractory.com/news/Refractory%20materials%20for%20different%20parts%20of%20electric%20ARC%20furnace(1).html
E-mail:sales8@chinaelong.com

Characteristic Refractory Material Mud Mixing Method

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