Refractories——Corundum

Corundum is one of the most important refractory raw materials, the use of corundum refractory products manufactured in aluminum MgO-C ladle, ladle prefabricated blocks, torpedo and other industries are widely used. Now, with the continuous development of high-temperature industrial technology, constantly upgrading equipment,

innovative theories, especially the application of new technologies in recent years, the metallurgical industry, more to promote the adjustment of product structure refractories, corundum in refractories use the proportion is growing.

In recent years, large and small manufacturers continue to rise corundum, production quality is uneven, use, corundum refractories produced in various industrial applications, there are various problems chalking bursting. The main problem is exposed high levels of impurities corundum, alumina content but related issues.

High impurity content of corundum,products will cave in there, it will affect the quality of subsequent products. The low alumina content intolerance can lead to corrosion of the products. Meanwhile corundum powder particles cause problems exposed cracks in the production of products, the bursting of the situation.

Corundum products because of non-compliance on the one hand a small production companies for lower prices deliberately low-quality goods, on the other hand there are the production and use of business-to-business product parameters sufficient reason Communication Department. Luoyang Yilong Refractory Co.Ltd help customers understand their requirements through the use of sales, specifications, parameters and other conditions, the concept of vague answer your technical staff is also actively through the exchange and technical visits with customers to fully understand customer intent determining product specific parameters. At the same strict quality control in the production process. Produced corundum product quality, stable performance. welcome to consult and order.

Refractories industry must keep pace with the times

This year my Refractory Factory (LuoyangYilong) circumstances, can determine the continuation of the current domestic refractories shipping price trend appeared, although the release of last year's major banks invariably loose interest, but also very difficult budget period a substantial profit. Restructuring of production and sales model, to enhance the industry credit, reduce transaction costs,

have become big businesses refractories, refractory materials prices continue to drop further at present, and slightly expanded, in the absence of sufficient growth in demand, the refractory plant continue to cut prices to sell .

The current situation is, wages rise refractory factory, is the rapid growth of the financial costs, the price index of refractory products continue downward. Also facing a more serious problem is the decline in profits, negative factors such as high-end equipment imported condescending is the most important factor in the refractory industry is facing difficulties. Imbalance between supply and demand, the industry must adjust the strategy, innovation, has become a trend, at this time, online marketing strategy has been quietly probe.

According to the actual circumstances of refractories, network marketing has become a trend, with the maturity of e-commerce models, online trading has become commonplace. E-commerce model system reform is not a cure-all prescription, guide enterprises in the public and individual agency reform, they should based on the principle of "seeking stability, and integrity," according to objective laws, integrity management, establish brand awareness, promote the transformation of the traditional model. Let refractories industry has to keep up with the development of the times. This is the trend, which is profitable. Internet marketing go this route, every industry needs and must be the way to go, just a matter of refractories industry is no exception.

Refractory for electric arc furnace lid

EAF uses A1203 65% -85% alumina brick masonry lid, the special needs of the site is also used tabular alumina brick (with a plate Al20390% -100%), but the price is expensive, silica brick is about 10 times higher 31V or thermal stress relief lid damaging effects of aluminum bricks, high alumina brick firing using phosphate bonded alumina bricks do not burn with white masonry made good use of effects. Some (HP) in high power electric furnace cover, the main use of high alumina bricks (about 80% Al2 03) and chemically bonded magnesia-chrome brick (Mg0> 65%, Cr2 037% _15%) Consolidated masonry furnace cover. High power (UHP) electric cover using mullite corundum brick, the brick main feature is a good thermal stability, resistance to high temperature load-deformation ability, it just to meet the requirements of the lid refractories, MK-80, No. MO corundum bricks,

is fused corundum and fused mullite particles strengthen the structure of products. 50t UHP EAF for cover, stainless steel and bearing steel smelting life increased by 25% -35% higher than magnesia-chrome brick roof.

High alumina brick lid. Alumina brick masonry furnace lid began in the late 1950s. At that time the use of high alumina brick lid (Ak 0365% -80%) increased by 4 times higher than silica brick lid life. Firing alumina bricks (A \ 2 03 80 16) and phosphate binding does not burn alumina brick (Al2 03 80% -85%) and mullite brick firing or not firing phosphate binding mullite brick, they have in common is an excellent thermal shock resistance. The life of the early 1960s, the lid has reached about 200 furnaces.

Five main quality indicators of refractory

• Refractoriness

Refractory nature in the course, resist high temperature without melting, called refractoriness.

Refractoriness refractory given temperature limit used is an important indicator of assessing the merits of the refractory quality.

• Thermal shock resistance

Refractory resist drastic temperature changes without cracking or peeling ability, called thermal shock resistance. This cyclical nature of the furnace heating and cooling operations is important.

• High-temperature structural strength

    At a high temperature and a certain load is applied to the refractory deformation temperature from the start of the deformation to some extent, the structure is called a high temperature or high strength load softening temperature. It is the ability of the refractory temperature and the load resistance while being deformed under the action of this nature and by the selection of a high temperature furnace under the building material force is important.

• Volume stability at high temperatures

    Refractory material for a long time under high temperature, resulting involume expansion, the expansion is called the residual.

Size refractory residual swelling, reflecting the quality of the high temperature volume stability: the smaller the residual deformation, volume stability, the better; contrary, the worse the stability of the volume, the more likely to cause deformation or damage to the masonry.

• Lag resistance

    Ability to resist the erosion of refractories and slag of molten material in

the course of soot and other damage without being called a slag resistance. Slag resistance is an important indicator of the refractory nature of the work you are, the higher the better ability of anti-slag. Good slag resistance refractory high life.

Special aluminum carbon refractories

Special refractory aluminum carbon and carbon refers to aluminum as raw materials, in most cases, added to other materials, such as SiC, metals Si, Al, etc., bonded together with an organic resin or pitch carbon composite binder special refractories. Broadly speaking, the alumina and carbon as main components are called refractory carbonaceous refractory aluminum. Aluminum carbon refractories their different production processes can be divided into two categories:

do not burn carbon refractories and firing aluminum aluminum carbon refractories.

Aluminum does not burn carbon refractories are bound carbon refractories, because of its antioxidant activity was significantly better than Bricks and excellent anti-corrosion performance system Na2O slag, so widely in the blast furnace, ladle hot metal pretreatment equipment, etc. applications. Aluminum carbon refractories are fired combined-type ceramic refractories, because of its high strength, good resistance to corrosion and thermal shock resistance, and thus a large number of suitable casting sliding gate system with skateboard brick and casting Big Three, namely long nozzle, submerged nozzle and overall stopper rods.

Alumina has a high resistance to acid, basic slag, metal and glass capacity effect solution. It is a high temperature in an oxidizing atmosphere or under a reducing atmosphere used can be a good effect. Carbon and graphite materials have a particularly high thermal conductivity and low coefficient of linear expansion, while a solution having a high temperature with no residue and wettability. So aluminum carbon brick has the following properties.

(1)    aluminum carbon refractories have excellent slag resistance and thermal shock resistance. Compared with magnesium carbon refractories, aluminum carbon refractories have better resistance to alkali TiO2 slag erosion and corrosion capabilities.

(2)    For aluminum baking carbon bricks, because silicon and carbon additives at a high temperature to form silicon carbide, so as to have a double bonding system, i.e., a combination of carbon and ceramic bond, and thus calcined alumina carbon refractory with high mechanical performance, not only act as a conventional continuous casting refractories, and is a functional configuration of the material.

Refractory industry developing trends——Cyanite

Future high-purity refractory materials will be the main and synthetic natural selection and use. Development and utilization of the "three stone" raw materials, namely andalusite, sillimanite, kyanite raw materials, can improve the microstructure and thermal properties LAS refractories.

As the "three stone" at high temperatures into the lower phase mullite and mullite expansion coefficient is small, help to improve the thermal shock resistance of the material. Andalusite in the material can be added with countless subtle diffusion thermal stress becomes void formation, making the stress to be released within the refractory, thus improving the thermal shock resistance. And sillimanite completely mullitization the temperature is higher, will help improve the high-temperature creep resistance. In addition, due to the volume expansion effect produced mullitization also accompanied by high temperature creep favorable. Development of high-quality synthetic refractory raw materials, the amount of developed countries in the use of natural raw materials reduced and the amount of high-purity synthetic raw materials is increasing, the reason is the extensive use of synthetic materials proportion of unshaped refractory materials is increasing, and the extensive use of natural raw clay brick, high alumina brick, zircon brick production is declining.

Therefore, innovation, research and development, education, management and investment, will be the key to maintaining the vitality of future refractory industry and success. Current and future years for Chinese refractories industry, is an experienced structural optimization, corporate restructuring and product structure adjustment period. China's strategy of development should be based on Chinese refractories rich natural resources, based on the development of high-performance synthetic materials and more high-performance, functional products to meet the advanced requirements of high temperature industrial development and a focus on clean steel casting and production. At the same time, you should pay attention to equipment and management, improve product quality refractory materials and the stability and reliability.

Refractory development in China

Ancient, medieval, Renaissance refractories, industrial revolution around the blast furnace, coke oven, stove refractories, refractory materials and new manufacturing processes post-modern manufacturing techniques and refractory major technological advances of modern,

as well as the future of refractories Prospects of development, refractories and high temperature technology accompanied appears roughly originated in the mid-bronze Age. China Eastern Han Dynasty has been made to burn wood and porcelain kiln sager clay refractories.

Early 20th century, the high-purity refractory, high density and ultra-high temperature product direction, while there has been complete without firing, small power consumption monolithic refractories and refractory fibers. Modern technology with the development of atomic energy, space technology, new energy technologies, high temperature, corrosion resistance, thermal shock resistance, excellent performance integrated erosion and other refractories has been applied. There are many factories in China producing refractory products. China is rich in resources, but also because the reasons for this, the major foreign investors came to China also have a go, emerge.

In China's northeast, is a supplier of refractory extremely lush areas, leading to other foreign investors lower their export prices have been questioned, which in 2003 proposed a new product for the Chinese refractories by the EU anti-dumping, limiting the product exports to the EU. 2006 China's raw material resources for the protection of a huge loss on the part of industry produced a relief rebate, thus greatly limiting refractory products exports. But this does not limit the number of foreign brands sold in large part because they have dozens or even hundreds of years of sales experience in production and market share dramatically, they also created the brand in every continent.