2017年8月21日星期一

Solutions to improve service life of ladle slide gate plate

slide gate plate
slide gate plate
Slide gate plate is the most important part among the slide gate nozzle system, which directly control the flow of the molten steel. Due to long time contact with high temperature molten steel and frequently strong heat impact, it easily got spoiled. Following are some solutions that could promote slide gate plate service life.

1.Types of slide gate plate
It is better to use the alumina- carbon based slide gate plate, which has a good erosion and strong thermal shock resistance. Bonded with carbon material, this type of slide gate characterized with high thermal conductivity and low thermal expansion coefficient.

2.Installation of slide gate plate
Make sure the fire mortar has a suitable proportion, mixed well and suitable proportion and no impurities. Never use the dried and lumpy mortar. It is also not acceptable to mix the new mortar with the used one. Make sure the upper nozzle is clean, no any residue in refractory company slide gate frame and sliding mechanism. Before installation, make sure the slide gate are not deformed or cracked. Keep the slide gate steady and smooth during the installation, and check whether there is any bump and swing after installation.

3.Using of slide gate plate
It is better to adapt auto cast program when casting steel, do not frequently and drastically open or close the slide gate. Once in need of burn oxygen, the slide gate plate must be fully opened and discharge the slide gate sand as much as possible.

Changxing Refractory material not only provides qualified slide gate plate, but also can dispatch technician for site service. Shall be any interest, please contact us.

Article source:
Solutions to improve service life of ladle slide gate plate

E-mail:sales8@chinaelong.com

The notes for using slide gate plate

slide gate plate
slide gate plate
1.Hot mechanical damage, hot chemical erosion and misoperation are the main three reasons for the damage of slide gate plate;

2.Use alumina zirconium carbon slide gate plate, ensure slide gate plate has good erosion resistance and thermal shock resistance; use slide gate and mechanism with reasonable design and even stress distribution, the service life of slide gate plate can be effectively improved;

3.Follow the standard operation procedure during the tapping of molten steel; right and good maintenance of refractory material slide gate plate can also improve the service life of slide gate plate.

Article source:
The notes for using slide gate plate
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2017年8月14日星期一

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


Refractory Brick
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

E-mail:sales8@chinaelong.com

Basic properties of refractory material for steel making

refractory material
refractory material
As we all know that refractory material 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 brick is 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 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 magnesia carbon brick 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 uncalcined 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 brick; for hot spots, furnace wall and tapping hole, using magnesia 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 material for steel making working circumstance is very bad. Therefore, whatever refractories 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 materials for furnace 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8月4日星期五

What are the refractory materials used in induction furnace

Induction furnace is more commonly used in a melting metal furnace, the current mainly used to melt molten iron, molten steel, copper, aluminum, according to the different melting products, the use of different Medium frequency induction furnace refractory lining materials.
General melting molten iron, the use of quartz sand dry vibration refractory material;
Melting molten steel, using magnesia or alumina material;
Aluminum is made of alumina or clay.
Specific to the furnace, also divided into: coil mud, mouth, mica and insulation layer, dry vibration material layer. General mouth with plastic.

More refractory material:
What are the refractory materials used in induction furnace

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What is refractory castable

refractory castable
refractory castable
Refractory castable is premixed combinations of refractory aggregates, matrix components or modifiers, bonding agents, and admixtures. It is classified in several ways. It is based on chemistries which separates the refractory castable based on alumina and alumino-silicate aggregates such as magnesite and dolomite.

Refractory aggregates constitute the basic skeleton of castable materials , and it is accounted for the largest amount of the formulation. Aggregates size can range from 10 mm to 300 mm. Aggregates are sized and proportioned for getting desired packing and particle distribution. Varieties of refractory material aggregates is workable. Castable is formulated based on one or combined aggregates to realize the desired chemistry, mineralogy, and physical properties.

The bonding agents used for insulating castable refractory  are varieties, including alumino-silicate castable. Calcium aluminium cement is still the main bonding agent for castable. Specialized castables have been developed for more than 20 years, by using non cement bonds such like hydratable alumina, clay, silica and alumina gels, and chemical bonds such like mono aluminum phosphate, phosphoric acid and alkali silicates. Basic castables rely on chemical or organic bonds, the most common types are alkali silicates, sodium phosphates, mineral or organic acids, and resins etc.

Article source:
What is refractory castable

E-mail:sales8@chinaelong.com

Solutions to improve service life of ladle slide gate plate

slide gate plate Slide gate plate  is the most important part among the slide gate nozzle system, which directly control the flow of the...