Why do refractory castables with mobility

Castable is a very wide range of refractory material, for its extensive use mainly because of its performance advantages, and significant features, we may be able to understand, it has a certain liquidity, it is because of the What, where Xiaobian to tell why the castable materials with liquidity.


The refractory castable is a kind of granular and powdered material made of refractory material, which is composed of a certain amount of binder and water.It has high fluidity, suitable for construction by pouring method and can be hardened without heating. It is made up of refractory aggregate, powder, binder, admixture, water or other liquid materials.It is usually cast in the field by casting, vibration or tamping, and can also be used as preform.

Analysis on Product Characteristics and Classification of Mullite Insulating Bricks

Mullite insulation brick is mullite (3Al2O3 · 2SiO2) as the main phase of the high-alumina refractories. General alumina content of 65% to 75%. Mineral composition In addition to mullite, which contains the lower alumina also contains a small amount of glass phase and cristobalite; containing higher alumina also contains a small amount of corundum. Mullite insulation brick can be directly used for high temperature furnace lining, has been widely used in shuttle kiln, roller kiln, glass and petrochemical furnace lining.

First, the mullite insulation brick product features:
1, low thermal conductivity, with good insulation effect;
2, mullite insulation brick low melting, due to low thermal conductivity, mullite series of lightweight insulation brick accumulation of little heat energy, intermittent operation in the energy-saving effect is obvious; 3, impurity content is very low, Metal and other oxide content, therefore, high refractoriness; higher aluminum content in the reducing atmosphere to maintain good performance;
4, mullite thermal insulation brick high pressure strength;
5, the appearance of accurate size, speed up the masonry speed, reducing the use of refractory material mud to ensure the strength and stability of masonry, lining to extend the life;
6, mullite insulation brick can be processed into a special shape. To reduce the number of brickwork and joints.
Second, the mullite insulation brick classification: mullite insulation brick according to the density of different light and heavy mullite bricks, according to the use of different temperature is divided into: 1350 mullite insulation brick, 1450 mullah Stone insulation brick, 1550 mullite bricks and so on. Mullite insulation brick performance and its application: high refractoriness, up to 1790 ℃ or more. The softening start temperature of the load is 1600 to 1700 ° C. Room temperature compressive strength of 70 ~ 260MPa. Thermal shock resistance is good. There are sintered mullite bricks and fused mullite bricks. Sintered mullite brick to bauxite clinker as the main raw material, adding a small amount of clay or bauxite as binder, by molding, firing and made. Fused mullite bricks to high bauxite, industrial alumina and fireclay refractories as raw materials, by adding charcoal or coke fine particles as a reducing agent, forming after the use of reduced melting method to manufacture. The fused mullite is more crystalline than the sintered mullite and has better thermal shock resistance than the sintered product. Their high temperature properties depend mainly on the alumina content and the homogeneity of the mullite phase with the glass distribution. Mainly used for hot stove top, blast furnace and the bottom of the furnace, glass furnace regenerator, ceramic sintering kiln, oil cracking system, such as dead angle lining.

Refractory bricks - High alumina bricks - Basic information

high insulating brick refractory than clay brick and semi-silica brick refractoriness should be high, up to 1750 ~ 1790 ℃, is a senior refractory
Al2O3 content of more than 90%, known as corundum brick. Because of different resources, national standards alumina brick are not entirely consistent. For example, European countries for high alumina refractory material Al2O3 content of the provisions of the lower limit of 42%. In China, according to alumina content in the high alumina brick is usually divided into three classes: Ⅰ and so on ─ ─ Al2O3 content> 75%; Ⅱ ─ ─ Al2O3 content of 60 ~ 75%; Ⅲ ─ ─ Al2O3 content of 48 ~ 60%.
Al2O3 in high alumina brick is close to neutral refractory and can resist the erosion of acid slag and alkaline slag. Because of containing SiO2, the ability of resisting alkali slag is weaker than that of acid resistant slag.
Alumina content of 48% or more of a neutral refractories material. From bauxite or other alumina content of the higher raw materials formed and calcined. High thermal stability, refractoriness above 1770 ℃. Slag resistance is good for masonry electric furnace, glass melting furnace, cement rotary furnace lining.
Mainly used for masonry blast furnace, hot stove, furnace top, blast furnace, reverberatory furnace, rotary kiln lining. In addition, high alumina brick is also widely used as open hearth lattice regenerative grid bricks, gating system with plug head, outlet brick. But the price of high-alumina brick clay brick than high, so with clay brick to meet the requirements of the place do not have to use high-alumina brick.

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.

Measures to extend the life of the ladle refractory material

In the normal production of steel, there are situations occur when the ladle gellan steel.Use good thermal conductivity refractory when lining-up may aggravate this phenomenon, combined with molten steel due to the temperature drop, which will create sticky residue lining the surface of serious problems within the ladle . Here Henan refractories plant was introduced to prolong the life of ladle magnesia carbon brick measures.

1. refractory brick for sale and masonry improve the way

In order to ensure that the masonry and flaking masonry lining less firmly connected properly changing the shape of the brick lining, made of shaped bricks to increase thermal stresses can be compensated by the number of vertical joints and bricks made of arc-shaped surface.Package wall spiral style method masonry, bricks can reduce consumption by more than 15%.

To prevent cracks between the blocks in LF ladle bottom lining erosion, Kobe Steel improved masonry structure. Concentric masonry package by the end of mullite corundum products, the central area (steel flow impact zone) with high alumina castable precast masonry block.This approach allows the masonry thinner than the central region surrounding the bottom half of the pack, lining life increased from 30 times 40 times, repair times reduced by two times 1 times.

Existing interface between the bricks can prevent crack propagation, interaction between the liner and the slag generated.Or between the safety liner and add a layer of tar dolomite working lining tar dolomite ramming material, or in use can be carbonized material.

2. Drying

(1) microwave heating

Microwave heating is a new thermal technology, compared with conventional heating, microwave heating without an external heat source, but the material is heated inside the microwave electromagnetic radiation, promote their movable particle motion, collide with each other so that friction heat. Monolithic refractories for ladle body construction using microwave heating, which greatly speeds up the reaction process, since the temperature difference between the surface and the interior of the small settlement burst release and tissue degradation phenomenon, the entire liner can be quickly heated and uniformly dense tissue . Heating time (conventional heating formerly required 24h) reduced to 8h.

(2) Quick baking apparatus

Anyang Iron and Steel Company second steel mill 25t ladle quick energy-saving baking apparatus using oxygen combustion, so that combustion gas can improve the thermal efficiency of over 50%.The practical production shows that it has a short baking time, adaptable, bake evenly, easy to operate, safe and reliable.Ladle down time from the past 40h 16h.Not only solves the gas pressure is low due to the impact Ladle problems, and effectively improve the baking quality of the ladle, to avoid the containment wall bricks crack phenomenon in the past due to the uneven baking caused.

(3) baking coal oxygen apparatus

Arm spin move or horizontal coal oxygen baking, preheat temperature in 1h refined package can reach 1000 - 1200 ℃. Effectively prevent slag line MgO-C, due to acute heat stress caused by thermal quench. Electric furnace refining temperature and time were decreased and shortened. Improve productivity and ladle life, reduce production costs and coordinate production order also plays a significant role.

3. Maintenance repair

Uneven ladle refractory lining is damaged, it is necessary to take repair, gunning and other measures to shore up weak links, to improve job ladle refractory consumption rate decreased, making the fullest use of the lining, to achieve the purpose of the high life.

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The reasons that the damage of ladle upper nozzle and its reventive measures

Ladle Nozzle is made from corundum, bauxite, flake graphite, antioxidant and phenolic resin formed on heavy duty presses in harden steel or carbide die by using white fused alumina. To obtain maximum packing density, nozzles are fired at extremely high temperature in order to increase corrosion resistance to metal and slag the fired nozzles are further processed.

1. The reasons that the damage of ladle upper nozzle
1) Under the scouring and erosion of liquid steel and steel slag, the slag erosion will occur under wrong operation process.
2) Mechanical damage during installation process.

2. To prevent the damages of refractory material sliding gate nozzle system, measures should be taken as below:
1) Use better raw material with high corrosion and erosion resistantance to make the upper nozzle, such as the corundum quality upper nozzle.
2) Choose to use products with high mechanical strength.
3) Note the operations of ladle casting process, to avoid the discharge of slag.

Article sourse:

http://www.yilongrefractory.com/news/The%20reasons%20that%20the%20damage%20of%20ladle%20upper%20nozzle%20and%20its%20reventive%20measures.html

Refractory Scrap: A World-traded Commodity

To most, the word ‘scrap’ evokes visions of unwanted, discarded leftovers. However, to the refractory industry, scrap represents a vital resource that enhances all aspects of refractory making.

The recycling of scrap refractories is an indispensable part of modern refractory industry, improving the industry's economic viability and reducing environmental impact. The recycling of scrap reduces the need for bauxite which is also named aluminous soil, thus significantly reducing CO2 emissions, water and energy consumption and air pollution.

As a result of these efficiencies, refractory scrap is increasingly being regarded as a raw material for manufacturing new products worldwide. Such scrap has become a globally traded commodity. 

There’s a trend that more and more steelmaking companies prefer to purchasing refractory products which are made of scrap in order to reduce the manufacturing cost. To catch up with the trend, a lot of plants start to recycle the scrap and then put them into reusing. It’s not only good to the environment but also make steelmaking companies benefit from such an behavior. 

For more information about refractories and scrap, go to the www.yilongrefractory.com.