Application fields and advantages of refractory castables

 As a new type of refractory material, castable is mainly characterized by high fluidity and is suitable for monolithic refractories formed by casting. Compared with other monolithic refractories, it has higher binder and moisture content and is fluid. Because of its better performance, the application range of unshaped refractories is wider, and the materials and binders used can be selected according to the conditions of use. It can be directly poured into a lining body for use, and can also be used as a prefabricated block by pouring or vibrating method.

Refractory castables are developed on the basis of low cement series refractory castables, and are a type of refractory castables that have developed vigorously in recent years. Its varieties include high-tech, high-performance and high-purity refractory castables, chromium-containing, carbon-containing and micro-expansion refractory castables, etc., which are mainly used in steel smelting furnaces, ladles, tundishes, fluidized bed boilers and regenerative heating furnaces on thermal equipment, the service life is increased and good economic effects are obtained.

Refractory castables use high-quality, high-purity or synthetic refractory raw materials and additives, ultra-fine powder technology, excellent binders and high-efficiency additives. Under the guidance of the basic theory of refractory materials, according to the use and operating conditions of various thermal equipment, scientific formulate the material formula, precisely adjust the particle size composition, reasonably select the binder and admixture, and formulate the new technology refractory castable with excellent performance and longevity. Taking the high-tech refractory castable for ladle as an example, it is characterized by sub-combination, self-sintering, and self-expansion under high-temperature use conditions. The "three-self" principle is also embodied in different degrees in the new technology refractory castables, so its performance is excellent and the service life is significantly improved.

High-quality, high-purity or synthetic refractory raw materials are the basis for the preparation of new-tech refractory castables, and also the basis for the production of high-efficiency unshaped refractory materials. Such as tabular corundum, dense corundum, white corundum, corundum mullite, alumina-magnesia spinel, high-purity magnesia and spherical high-bauxite clinker. In addition, brown corundum, white corundum, sub-white corundum and aluminum-magnesium spinel are made from high-quality bauxite clinker and other raw materials after sintering or electric melting. Process treatment, its performance is excellent, can partially replace alumina-based synthetic materials, and is widely used.

The excellent performance of refractory castable means that its performance indicators are suitable for the use requirements of thermal equipment and can achieve the purpose of longevity. Without the longevity of the kiln, excessive pursuit of performance indicators is of no benefit.

The scope of application of new technology refractory castables is also defined. For example, ultra-fine powder combined with magnesia refractory castable is applied on the ladle slag line, and the effect is better, but as the anti-slag material at the bottom of the heating furnace, because the use temperature is about 1200 ℃, the sintering strength is not reached, and it is difficult to achieve good results. .

Refractory castable is a milestone in the history of the development of unshaped refractories. Its important sign is its entry into the high-temperature smelting furnace of steelmaking and ironmaking, and significant results have been achieved. In the future, according to the use and operating characteristics of the kiln and its thermal equipment, advanced raw materials, scientific formulas, reasonable grading, and elaborate production will be used to develop new high-performance and functional refractory castables to meet the needs of my country’s iron and steel industry. The need for rapid development.

We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. Our high quality refractory products 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:Application fields and advantages of refractory castables
Company name: Henan Changxing Refractory Materials Co.,Ltd
More refractory products:https://www.cxrefractories.com/en-product-solution
Email:info@cxrefractories.com
Website:https://www.cxrefractories.com

Refractory castables and measures to increase their service life

 As we all know, refractory castable is a kind of amorphous refractory without calcining. It is made up of refractory aggregate, refractory powder and cement in a certain proportion; it has good fluidity after adding water and stirring during construction. Then it is formed and cured (to be baked according to a certain temperature system) to make it condense and harden. The use characteristics of refractory castables are as follows: First, the masonry structure has few joints, strong integrity, and good sealing. It can avoid the infiltration of clinker powder during application and operation; Second, it is easy to anchor and convenient to construct, which is beneficial to improve masonry. Efficiency and masonry quality; The third is that raw materials are widely used, which is convenient for comprehensive utilization of resources, and the delivery time is short, which can reduce inventory and related costs accordingly.

With the gradual expansion of the application of refractory castables, its life cycle has become the most concerned issue of all owners. In order to ensure the life cycle that meets the design requirements, the following aspects should be achieved: First, a strong manufacturer should be selected to ensure the quality of the refractory castable itself; Second, a reasonable selection and configuration should be carried out according to the use environment; It is necessary to have a reasonable construction plan and strict construction process control measures during construction, including proportioning control, molding quality control and reasonable maintenance, heating system control and so on.

Popularly speaking, refractory castable is a kind of high-temperature-resistant concrete, so it also conforms to the theory of concrete. For example, the amount of water added is the fundamental reason for controlling whether the refractory castable can achieve the design strength. However, driven by profits, some construction parties will add a lot of water to the castable in order to speed up the construction progress during the construction of refractory castables, resulting in the use of the kiln refractory lining after the construction is much lower than the design requirements , Even after half a year of use, serious problems have occurred and must be overhauled (and for well-constructed refractory castables, there is no need for overhaul after 3 to 5 years of use). We know that refractory investment accounts for a small proportion of the entire plant investment (about 2% to 4%), but its impact on the future operation of the entire system is very large. The loss due to a refractory lining accident for a day of stopping can be as little as hundreds of thousands or even millions. Therefore, ensuring the high operating rate of the firing system can achieve the high-quality, high-yield and low-consumption operation of the system. Therefore, the construction process control of refractory castables is particularly important. Usually we should strictly follow the following regulations.

First, the amount of water added to the castable should be strictly controlled in accordance with the instructions for use, and should not exceed the limit. On the premise of ensuring the construction performance, the amount of water added should be less than more.

Second, the mixing time of the castable is not less than 5min. When operating, use a compulsory mixer. When mixing, dry mix first, and then add 80% of the amount of water to stir. Then, depending on the degree of dryness and wetness, slowly add the remaining water and stir until Obtain a suitable working consistency.

Third, the pouring material poured into the mold frame should be immediately stratified with a vibrating rod. The height of each layer should not be greater than 300mm, and the vibration spacing should be 250mm. When vibrating, try to avoid touching the anchors and not damaging the heat insulation. Do not vibrate and re-vibrate on the same part for a long time. After seeing the reflow of the castable surface, the vibrating rod should be slowly withdrawn to avoid segregation and voids in the castable layer.

Fourth, when pouring a large area, the construction should be divided into blocks. The pouring area of each block should be about 1.5m2. The expansion joints should be set according to the design and should not be omitted. The expansion joints should be set in the middle of the anchor interval.

We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. Our high quality refractory products are good sold to many countries say South Africa, Bangladesh, Indonesia, Malaysia, etc.?

Article Source:Refractory castables and measures to increase their service life
Company name: Henan Changxing Refractory Materials Co.,Ltd
More refractory products:https://www.cxrefractories.com/en-product-solution
Email:info@cxrefractories.com
Website:https://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

Refractories in cement industry

Alkaline Refractories 
Alkaline refractory material is available for high temperature calcination,also has superior chemical resistance property, which is a main material for cement kiln to keep high production quality, high yield, low consumption and long-term safe operation. Currently main material for cement kilns include direct-bondedmagnesiachrome brick, semi-direct bonded magnesiachrome brick, ordinarymagnesia chrome brick , dolomite brick, zirconium and zirconium-free special magnesite brick, spinel brick and chemically bonded unburned magnesia chrome brick.
Bricksproperties are listed as follows:
High alumina brick 
High alumina brick has high compressive strength, high refractoriness under load and good thermal shock resistance. Because of its low cost with high quality, it is widely used in varietiesof cement kilns. When to be used in arch crown, calcined alumina brick is better.
High alumina bricks suitable for cement kilns includephosphate bonded alumina brick, phosphate bonded high alumina wear-resistant brick, anti-stripping alumina brick, chemically bound (special) alumina brick and general alumina brick and so on.

Alkali Brick Series
Alkali brick has excellent alkali corrosion performance, under certain conditions, it will react with the alkali compound kiln materials and kiln gas, rapidlyforming enclosed type dense protective enamel layer on the turn, preventingthe continuing internal mixing and bricks "base crack ", which is a indispensable kiln lining material in NSP kiln. This series bricks include ordinary alkali-resistant brick, high-strength alkali-resistant brick, insulation alkali-resistant brick and arch type alkali-resistant brick.
Series refractory castables 
Refractory castables can be produced with simple production process, which is flexible and convenient to be used in the cement kiln system. It has become increasingly common to be applied in the complex structure of cement kiln preheater system. Refractory castables suitable for cement kiln mainly include corundum castable, high alumina castable, alkali-resistant castablesand lightweight castable.
Article Source:Refractories in cement industry
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/

Methods to masonry of boiler castable

There are several methods could be taken, to protect the boiler castable from being destroyed during masonry.
(1) The balance of refractory castable and water is important, adding not too much or too little water.
(2) Blended castable should be used within 30 minutes, and please add it to the certain depth and length at a time.
(3) Mold of it could be demolished after the castable is strong enough. The load-bearing form should be demolished when the castable reaches 70% of the strength. In order to facilitate stripping, pouring all the mold before pouring surface should be coated with a layer of oil.
(4) After the boiler masonry to have enough natural drying period, so that most of the refractory layer of water can be precipitated.
(5) Before the oven, the furnace lining material must have a certain natural strength (enough safety period) to carry out. Oven principle "should not be short, should be slow should not be fast."
Changxing refractory provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, Magnesia Carbon Brick, clay refractory bricks and other refractory products.
Article Source: Methods to masonry of boiler castable
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/

Silicon carbide based refractory materials

Silicon carbide (SiC) is an artificial mineral, refractory raw materials for the silica and coke, 2000 ℃ above the high temperature electric furnace synthesis, silicon carbide refractory is divided into three categories: (1) plus clay and other oxide-bound products; (2 ) Nitride-bonded products; (3) the use of silicon carbide recrystallization, pressure molding self-bonding products. One of the most common application of clay bonding products, China is currently the production and use of this one.

Carbide as a binder of silicon carbide grade products containing SiC87%, refractoriness up to 1800 ℃, load softening point 1620 ℃. The silicon carbide products have some special properties that make it suitable for certain applications such as (1) its thermal conductivity is about 10 times higher than that of conventional refractory materials and is suitable for use as heat-conducting devices such as heat treatment furnaces Cover. Because of its good thermal conductivity, 1200 ℃ below a strong antioxidant, so the life than the metal cover long. According to the same reason, can also be used as heat exchanger components. (2) mechanical strength, good wear resistance, resistance to rapid cooling hot or good, so some of the roller furnace with it for easy to wear roller sets, the cost is lower than the heat-resistant steel. (3) larger than the resistance, can be used as electric resistance of the furnace.

We are mainly producing high alumina brick, high alumina refractory fire bricks, alkali resistant brick, castable, clay brick, insulation brick, light high alumina brick, low creep high alumina brick, high aluminum wear Brick, high aluminum lightweight insulation brick, clay insulation brick, if you have any need contact us anytime.

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

Refractories used in cement industry

Alkaline Refractories 
Alkaline refractory material is available for high temperature calcination,?also has superior chemical resistance property, which is a main material for cement kiln to keep high production quality, high yield, low consumption and long-term safe operation. Currently main material for cement kilns include direct-bonded magnesia chrome brick, semi-direct bonded magnesia chrome brick, ordinary magnesia chrome brick , dolomite brick, zirconium and zirconium-free special magnesite brick, spinel brick and chemically bonded unburned magnesia chrome brick.
Bricks properties are listed as follows:
High alumina brick
High alumina brick has high compressive strength, high refractoriness under load and good thermal shock resistance. Because of its low cost with high quality, it is widely used in varieties of cement kilns. When to be used in arch crown, calcined alumina brick is better.
High alumina bricks suitable for cement kilns include phosphate bonded alumina brick, phosphate bonded high alumina wear-resistant brick, anti-stripping alumina brick, chemically bound (special) alumina brick and general alumina brick and so on.

Alkali Brick Series
Alkali fire brick has excellent alkali corrosion performance, under certain conditions, it will react with the alkali compound kiln materials and kiln gas, rapidly forming enclosed type dense protective enamel layer on the turn, preventing the continuing internal mixing and bricks "base crack ", which is a indispensable kiln lining material in NSP kiln. This series bricks include ordinary alkali-resistant brick, high-strength alkali-resistant brick, insulation alkali-resistant brick and arch type alkali-resistant brick.
Series refractory castables 
Refractory castables can be produced with simple production process, which is flexible and convenient to be used in the cement kiln system. It has become increasingly common to be applied in the complex structure of cement kiln preheater system. Refractory castables suitable for cement kiln mainly include corundum castable, high alumina castable, alkali-resistant castables and light weight castable.
Article Source:Refractories used in cement industry
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/