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!

Article source:
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.

Article source:

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.

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

E-mail:sales8@chinaelong.com

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.

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

2017年6月28日星期三

Development of continues casting & tundish

Refractory Castable
Refractory Castable
CCM first appear in 1950s, it is characterized by fast casting and focus investment. CCM technology was developing in a very fast speed. In Year 1970, CCM only took 5.6% all over the world, refractory brick while the data reached 62.4% in Year 1990, and in some developed countries, it was even 95%. In recent years, many steel plants adapted CCM instead of mould casting. Until Year 1994, in total 24 countries are of full CCM now.

Compared with traditional mould refractory castable casting, CCM can improve metal recycle rate and low down power consumption. CCM can make the melting work simple and short the melting time, in which way the production efficiency can improve in a large degree. Tundish is a middle progress of steel making, and it is the kep point which can decide continues casting or not. Furthermore, tundish would have a big effect on melten refractory material steel quantity and quality. Its functions are as following:

1. Diversion. For multi-strand CCM machine, the melten steel would be divided from tundish.

2. Continues casting. When refractory firebrick multi-furnace continuous casting, tundish can be a holder when changing ladle.

3. Lowing down presure.

4. Protecting melten steel quality. Through using covering agent, long nozzle and other protecting device, tundish can help to protect the melten steel quality.

Article source:
Development of continues casting & tundish

E-mail:sales8@chinaelong.com

2017年6月19日星期一

Basic properties of refractory material for steel making

As we all know that China refractory is of various kinds and is widely used and also of great importance in steel industry. The following are some refractories commonly used in steel industry summarized by Changxing Refractory engineers.

(1) Refractories for converter
Magnesia carbon refractory brickis used for furnace cap, tapping converter mouth, before and after the surface, weld pool and bottom; high strength magnesia carbon brick is used for trunnion and slag line. Usually the MgO content in magnesia carbon brick is 70 ~ 75%, graphite is 16 ~ 20%, bulk density is 2.8 ~ 2.9 g/cm3, compressive strength is 25 ~ 30 MPa. The elements of high strength magnesia carbon brick are the same elements as magnesia carbon fire brick, but its compressive strength should be 30 ~ 42 MPa.

(2) Refractories for electric furnace
Furnace hearth, furnace slope and molten pool are overall rammed with magnesia clinker, or constructed with magnesia brick which is made of magnesia carbon brick and tar asphalt; high-quality MgO-C bricks is used for hot and slag line area; magnesia brick and magnetite chrome brick are used for tapping hole and the two sides of furnace door; high alumina bricks or high alumina brick clay brick are used for furnace cover.

(3) Refractories for UHP EAF
For permanent lining of ultra high power EAF, using magnesium stone; for furnace doorjamb, using magnesia chrome brick; for slag line, eccentric bottom and molten pool, using magnesia refractory firebrick; for hot spots, furnace wall and tapping hole, using magnesite carbon brick; for furnace cover, using high alumina brick; for tapping hole filler, using high ankerite filling material.

According to the working conditions of various steel furnaces, it can be proved that the refractory materials for furnace working circumstance is very bad. Therefore, whatever refractory for smelting are used, it must possess the following properties.
(1) High temperature resistant and high refractoriness.
(2) Erosion and erosion resistance to high temperature molten steel and slag.
(3) The steelmaking furnace works discontinuously, thus requires refractory material with good thermal shock resistance and spalling resistance.
(4) High mechanical strength, can withstand impact of furnace tilting and furnace charge loading with no damage.

Article source:
Basic properties of refractory material for steel making
E-mail:sales8@chinaelong.com

2017年5月24日星期三

Converter magnesia carbon brick

Converter magnesia carbon brick
Changxing Refractory magnesia carbon brick factory is located in the magnesium capital of China, and products with high bulk density and low porosity.
Magnesia carbon brick for converter
Magnesite and graphite as the main refractory raw material for the converter lining made of magnesium carbon refractory material products.
Performance converter magnesia carbon brick with high temperature, slag resistance, good thermal shock resistance, high temperature strength and so on. But its disadvantage is easy to oxidize in use, can be improved by adding antioxidants. Its physical and chemical properties see table.
The main raw material for the production process is fused magnesia or high purity sintered magnesite and high purity graphite. Generally, MgO is larger than or equal to 95%, and the c content in graphite is more than or equal to 94%. With phenolic resin or asphalt as a binder, according to the use of conditions to select the appropriate additives, by ingredients, kneading, molding, heat treatment made after the finished product. (See magnesia carbon brick) used in the smelting process, due to the use of various parts of the converter conditions and damage are different. In order to achieve a balanced corrosion, for different conditions of use of the converter parts, the choice of MgO-C bricks grades and quality are also different.
Furnace mouth, furnace cap parts of the temperature changes drastically, by the slag corrosion is more serious, should use good thermal shock resistance, slag resistance of magnesia carbon brick. Trunnions on both sides in addition to the role of damage when blowing, the surface without covered with slag layer, easy to repair, easy to oxidize the brick. Should be masonry good slag resistance, good oxidation resistance of high quality magnesia carbon refractory brick. Slag line parts and slag long-term contact, by slag corrosion serious, to be masonry and into the direct impact of scrap and molten iron and erosion. Should be used with a strong anti-slag, high temperature strength, good thermal shock resistance of magnesia carbon brick. Hearth, the bottom of the furnace compared with other parts of the erosion of light, the choice of ordinary magnesia carbon brick, when the top and bottom composite blowing technology, especially at the end of CO2, O2 and other gases, the damage is more serious. Should use good oxidation resistance, good thermal shock resistance, high temperature strength, high slag resistance of high-grade magnesia carbon brick. According to the different parts of the converter, the corresponding performance of magnesia carbon brick is to improve the technical indicators of the converter and effective method.

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

Neutral ramming mass is used for induction furnace lining with longer service life. In recent years,  silica ramming mass  is widely u...