The cause of slagging in ladle slag line

 1. For a long time to be poured, the top slag of molten steel cools and crusts, causing slagging on the ladle slag line.

(1) The cold heading steel process of Shaoguan Steel Plant requires bottom blowing of argon after the calcium treatment, weak blowing for 12-20 minutes. During the weak blowing process, the edge of the slag layer on the surface of the molten steel is basically in a static state. After a long period of temperature loss, the slag temperature continues decrease, the slag layer close to the ladle wall will solidify at the position of the ladle slag line, causing slagging on the ladle wall.
(2) The smelting cycle of the converter is shorter than the smelting cycle of the LF refining furnace, the pouring order is inadequate, the smelting speed of the previous process is too fast, the backlog of molten steel in the refining area is serious, and the waiting time is too long after the refining and smelting is completed until the continuous casting and casting. This is the main cause of slagging in the ladle slag line.

2. The Al2O3 content in the cold heading steel slag system is high, and the molten steel slag is sticky. After the refining is completed, the molten steel will solidify and condense at the position of the ladle slag line as the temperature of the slag surface decreases during the process of quenching.
According to field observations, when smelting aluminum killed steel, the ladle slag line is prone to slagging, while when smelting silico-manganese killed steel, the ladle slag line is slightly sticky.
The content of Al2O3 in aluminum killed steel slag is high [2]. In order to ensure the purity of molten steel, the amount of lime added is also large, forming a thicker and denser slag crust; silico-manganese killed steel does not contain Als, which produces Al?O? is also very small, so the amount of lime added is small and the slag layer formed is thin. It can be inferred that ladle slagging is greatly affected by the content of Al?O? in the slag.

3. The ladle slag line bricks are eroded seriously, causing depressions and slagging easily. Ladle slag line bricks refer to refractory bricks built from the third to the eighth layer of bricks from the bottom of the ladle mouth. After the ladle is filled with steel, the molten steel level fluctuates up and down with the amount of molten steel. When the converter smelting is finished, the partial oxide slag in the furnace is poured into the ladle along with the molten steel, commonly known as "slag". Sub-refining and slagging are used to remove excess oxygen in molten steel, that is, "deoxidation". The deoxidized slag is reduced slag.
As the alkalinity in the slag changes, the refractory bricks on the ladle wall that contact the slag are gradually dissolved and fall off, forming a depression in the ladle wall. When the alkalinity in the slag stabilizes, the slag and the ladle slag line bricks are mutually dissolved and combined to form slagging. The recessed wall of the slag will hang support points for the slagging, making slagging more and more easier.
In order to save costs and increase the turnover rate of the ladle, the ladle slag line bricks are not repaired in time after being etched, or the standard use is reduced, which greatly increases the probability of ladle slagging. Ladle slag line bricks have poor quality, poor corrosion resistance, poor permeability resistance, and quality problems such as cracks, which accelerate the erosion of the ladle slag line bricks and accelerate the slagging of the ladle slag line.

We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. Our high quality magnesia carbon bricks are good sold to many countries say South Africa, Bangladesh, Indonesia, Malaysia, etc. Shall any interests, welcome to contact us. Our team would make best to be your reliable partner.

Article Source:The cause of slagging in ladle slag line
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: info@cxrefractories.com
Website:http://www.cxrefractories.com

Production process of cold head series molten steel in a steel making plant

 1. Converter → LF furnace → vacuum RH furnace → billet continuous caster.

2. Converter → vacuum RH furnace → LF furnace → billet continuous caster.
3. Converter → LF furnace → billet continuous caster.
After the LF furnace exits the station, the slagging is cooled during the pouring process, and the crust is still hung at the position of the ladle slag line after the molten steel is poured. This makes the ladle cleaning operation more difficult and workload, and the reuse of the steel slag left by the ladle will cause problems.

For example: the slagging on the wall of the ladle hangs in the air after the casting of the continuous caster, and falls to the bottom of the ladle under the action of gravity to form slagging at the bottom of the ladle. At the same time, some steel slag will be scattered in the ladle nozzle, blocking the nozzle, causing the molten steel to be unable to start pouring after reaching the continuous caster platform.

We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. Our high quality magnesia carbon bricks are good sold to many countries say South Africa, Bangladesh, Indonesia, Malaysia, etc. Shall any interests, welcome to contact us. Our team would make best to be your reliable partner!

Article Source:Production process of cold head series molten steel in a steel making plant
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: info@cxrefractories.com
Website:http://www.cxrefractories.com

Brief introduction of induction furnace lining material

 Refractories used in intermediate frequency furnaces are mostly dry, such as dry ramming materials, also called knotting materials. According to their chemical properties, refractory materials include neutral, alkaline and acidic materials. Induction furnaces, etc., select suitable refractory materials according to the characteristics of the furnace and the environment.

For the lining of the intermediate frequency furnace for melting cast iron, generally cheaper quartz sand is used as the knotting material. When the smelting temperature is high and the smelting conditions are relatively harsh, the service life of the quartz sand knotting material will be greatly reduced, which cannot meet the user's requirements. At this time, it is necessary to use dry knotting materials such as magnesia, magnesia aluminum, magnesia chromium, etc. (that is, the alkaline lining material that everyone often calls).

What are the common molding methods for refractory materials:

There are many molding methods for refractory materials. Common molding methods include extrusion molding, vibration molding, extrusion molding, ramming molding, isostatic pressing molding, melting casting molding, grouting molding, etc. The choice of forming method is mainly based on the nature of the mud, the shape, size and other process requirements of the embryo body. Except for the fact that most refractory materials are formed by press forming and vibration forming is used to form large shaped blanks. Extrusion molding is generally used For the forming of tubular blanks, grouting is generally used for forming hollow thin-walled blanks. Isostatic pressing is currently mainly used in the production of high-performance refractories.

Of course, the choice of molding method is also restricted by the equipment conditions of the production plant, so some products can't use the molding method. In this case, the company should choose other more suitable molding methods on the premise of meeting the technical requirements of the product.

Intermediate frequency furnace refractory knot forming method:

1. The sand should be manufactured according to the regular particle size and mixed evenly with additives. If you choose wet knotting, you can add 1% to 2% of the water, mix and put it for 1 to 2 hours before use.

2. Spread asbestos cloth on the inside of the sensor.

3. Knotted at the bottom of the furnace. After adding the sand material in batches, repeat the tamping with a pointed steel drill with a diameter of 12 to 14 mm each time. The furnace bottom knotting and feeding times are 4 to 5 times. The thickness of the furnace bottom is generally knotted to a regular height, and each knotting time is at least 10 minutes.

4. Put in the crucible core, which is the mould that controls the shape and volume of the crucible.

5. Knotted at the furnace mouth.

Article Source:Which refractory materials are used in the intermediate frequency furnace

Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd

Email: info@cxrefractories.com

Website:http://www.cxrefractories.com

Which refractory materials are used in the intermediate frequency furnace?

Refractories used in intermediate frequency furnaces are mostly dry, such as dry ramming materials, also called knotting materials. According to their chemical properties, refractory materials include neutral, alkaline and acidic materials. Induction furnaces, etc., select suitable refractory materials according to the characteristics of the furnace and the environment.　　

For the lining of the intermediate frequency furnace for melting cast iron, generally cheaper quartz sand is used as the knotting material. When the smelting temperature is high and the smelting conditions are relatively harsh, the service life of the quartz sand knotting material will be greatly reduced, which cannot meet the user's requirements. At this time, it is necessary to use dry knotting materials such as magnesia, magnesia aluminum, magnesia chromium, etc. (that is, the alkaline lining material that everyone often calls).

What are the common molding methods for refractory materials:

There are many molding methods for refractory materials. Common molding methods include extrusion molding, vibration molding, extrusion molding, ramming molding, isostatic pressing molding, melting casting molding, grouting molding, etc. The choice of forming method is mainly based on the nature of the mud, the shape, size and other process requirements of the embryo body. Except for the fact that most refractory materials are formed by press forming and vibration forming is used to form large shaped blanks. Extrusion molding is generally used For the forming of tubular blanks, grouting is generally used for forming hollow thin-walled blanks. Isostatic pressing is currently mainly used in the production of high-performance refractories.

Of course, the choice of molding method is also restricted by the equipment conditions of the production plant, so some products can't use the molding method. In this case, the company should choose other more suitable molding methods on the premise of meeting the technical requirements of the product.

Intermediate frequency furnace refractory knot forming method:

1. The sand should be manufactured according to the regular particle size and mixed evenly with additives. If you choose wet knotting, you can add 1% to 2% of the water, mix and put it for 1 to 2 hours before use.

2. Spread asbestos cloth on the inside of the sensor.
3. Knotted at the bottom of the furnace. After adding the sand material in batches, repeat the tamping with a pointed steel drill with a diameter of 12 to 14 mm each time. The furnace bottom knotting and feeding times are 4 to 5 times. The thickness of the furnace bottom is generally knotted to a regular height, and each knotting time is at least 10 minutes.
4. Put in the crucible core, which is the mould that controls the shape and volume of the crucible.
5. Knotted at the furnace mouth.

Article Source:Development of VOD ladle lining refractories

Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd

Email: info@cxrefractories.com

Website:http://www.cxrefractories.com

Development of VOD ladle lining refractories

 Magnesia-chrome brick was first used in VOD ladle lining because of its excellent slag resistance. However, under intermittent operation of VOD ladle, magnesia-Chrome brick is easy to produce spalling damage and poor thermal shock resistance. Because of the environmental protection of hexavalent chromium, the use of chromium-containing refractories is more and more restricted. At present, domestic stainless steel steel mills have rarely used magnesia-chrome brick.

In Europe, VOD ladle lining is mostly made of (magnesium) dolomite bricks. Compared with magnesia-Chrome brick, dolomite brick has good thermal shock resistance due to its high temperature flexibility. Most VOD ladles in China use magnesium-calcium bricks fired at high temperature. Although magnesium-calcium brick has the function of purifying molten steel and has better thermal shock resistance than magnesium-chromium brick, the content of CaO in the brick reduces slag erosion resistance under the condition that the slag composition of VOD ladle varies greatly and is mainly acidic slag. Due to the hydration problem, magnesium-calcium brick is not suitable for intermittent production, and the management of storage, use and other aspects puts forward very high requirements.

In the smelting of low carbon and ultra-low carbon stainless steel, stainless steel plants are reluctant to use magnesium carbon brick for fear that the liquid steel may be carburized by using magnesium carbon bricks in VOD ladle. In fact, these problems can be minimized by using low-carbon magnesium-carbon bricks. Although low carbonization tends to reduce the thermal shock resistance, the bricks with excellent thermal shock resistance can be developed by selecting the best amount of special asphalt and antioxidant.

Article Source:Development of VOD ladle lining refractories
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: info@cxrefractories.com
Website:http://www.cxrefractories.com

Slag regulating material for converter slag splash protection

Slag splashing furnace protection is a new technology developed this year to increase converter age. The basic principle is that after the final molten steel is blown, the remaining MgO content reaches the saturated or supersaturated final slag, and a high-pressure nitrogen gas of 0.8-0.9 MPa is blown at 0.8-2.0 m at the theoretical level of the molten pool using a spray gun , Spatter the slag and form a layer with a high melting point on the surface of the furnace lining. The slag-spattering layer adheres well to the furnace lining to protect the furnace lining.
The effect of slag splashing furnace protection is mainly determined by the MgO content in the slag before slag splashing. The addition of slag regulator can increase the MgO content in the slag. There are two ways to add it: adding slag adjuster after tapping to make the MgO content meet the requirements of slag splashing furnace protection; when the converter is blowing, add the slag adjuster and the slagging material into the furnace and control the final slag composition to make the MgO content meet the requirements. The commonly used slag conditioner and its chemical composition are shown in Table 1. When selecting a slag conditioner, the MgO content in the slag conditioner and its price should be comprehensively considered.

Table 1 Commonly used slag conditioner and its chemical composition（w）

Raw Material	CaO	SiO2	MgO	LOI	MgO
Metallurgical magnesia	8.0	5.0	83.0	0.8	75.8
Light burned magnesia ball	1.5	5.8	67.4	22.5	56.7
Light burned dolomite	51.0	5.5	37.9	5.6	55.5
Magnesium-containing lime	81.0	3.2	15.0	0.8	49.7
Raw dolomite	30.3	2.0	21.7	44.5	28.3
Magnesite slag grains	0.8	1.2	45.9	50.7	44.4

Article Source:Slag regulating material for converter slag splash protection
Company name：Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email:?sales1@chinafirebrick.com
Website: http://www.cxrefractories.com/

Brief Introduction for EAF refractories

EAF(Electric Arc Furnace) is mainly used for steelmaking industry, main raw material of which is scrap.According to power types, EAF are mainly divided into DC EAF and AC.
Same as other high temperature induction furnaces, refractory materials are widely used in EAF. EAF refractory materials are mainly as following,
1.DC EAF
Magnesia, magnesium carbon, magnesium aluminum and magnesium chrome refractories are widely used in DC EAF. Alkaline bricks without carbon is widely used in Europe, while in Japan, thermal shock resistance is thought as a great question, so they prefer to use magnesium carbon bricks with high carbon content. In order to improve thermal shock resistance and corrosion resistance of metallurgical equipment, magnesia spinel materials and magnesia-chrome brick are widely used in Europe.

2.AC EAF
For small AC EAF, asphalt brick, magnesium carbon brick, magnesia gun mix are widely used at furnace wall. For ultra-high power electric AC EAF, high-quality magnesium carbon brick would be used for furnace wall, while for slag line, higher performance high-magnesium carbon brick would be needed. Out of magnesia carbon bricks, magnesia gun mix would be used to repair furnace wall during working.
We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. Our high quality magnesia carbon bricks are good sold to many countries say South Africa, Bangladesh, Indonesia, Malaysia, etc. Shall any interests, welcome to contact us. Our team would make best to be your reliable partner.

Article Source:magnesium carbon bricks
Company name:Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/