The application of Al2O3-C submerged entry nozzle

Al2O3-C submerged entry nozzles, take corundum and graphite as the basic raw materials, add metal silicon, silicon carbide, molding in the isostatic press, and then sintering.

This nozzle, with uniform structure, low infiltration to molten steel, strong erosion resistance, so it could be used for casting of most types of steel. A12O3-C submerged entry nozzle must be preheated to use, otherwise, the nozzle has the risk of cracking. In the preheating process, there will be graphite burning (decarburization), the nozzle surface layer apparent porosity increases, reducing its anti-erosion.

Another disadvantage of the submerged entry nozzle is poor slag resistance, good thermal conductivity, and thus the slag line is serious erosion and the inner wall of the nozzle is easy to condensate steel. It is necessary to take effective measures to protect submerged entry nozzle: such as add refractory fiber protective cover outside of the submerged entry nozzle, smear anti-oxidation layer on the surface, slag line with composite ZrO2-c material to improve slag erosion resistance and blow argon gas into the porous refractory layer on the inner wall of the nozzle.
There have many kinds of refractory products in our factory, such as refractory fire brick, refractory nozzle, refractory raw material and other refractory products. Welcome to view our website to know more information about refractory products.
Article source: http://www.chinafirebrick.com/Company_News_114.html

The requirements of refractory materials in cement rotary kiln burning zone

1. When the cement rotary kiln rotating lap, the refractory in the kiln will be exposed to the gas in the kiln once. In addition to the time, the refractory materials are covered by the material, so the kiln refractories hot surface temperature will be subject to periodic thermal shock, which requires the refractory materials in the burning zone have good thermal shock stability.

2. Cement rotary kiln in normal operation, there must have stable burning zone lining brick. And the “kiln skin” can not be too thick or too thin. When the “kiln skin” is too thick, it will affect the normal calcination, affecting production; if the “kiln skin” is too thin, the meting loss of refractory materials is large. So the refractory materials need a good hang "kiln skin" ability.

3. Cement clinker will form silicate liquid phase at high temperature and silicate liquid phase easily penetrate into the refractory fire bricks, resulting in refractory chemical composition and mineral composition changes or even damage. Therefore, refractory materials need have strong resistance to erosion. There have many kinds of refractory products in our factory, such as fire brick for sale, refractory nozzle, refractory raw material, refractory nozzle. Welcome to view our factory to know more refractory products.
Article source: http://www.chinafirebrick.com/Company_News_113.html

Would u like to know effect of raw materials on properties of magnesia carbon bricks?

Magnesia, the main raw material of magnesia carbon brick, its quality has a very important influence on the performance of magnesia carbon brick. How to choose magnesia is the key to produce magnesia carbon brick. There is fused magnesia and sintered magnesia, they have different characteristics. Fused magnesia: large grain, less impurities and silicate phase, high direct combination of grain with less grain boundary. Sintered magnesia: fine grain, more impurity and silicate phase, poor direct combination.

For the raw materials of magnesia, in addition to the chemical composition, in the organizational structure, also requires high-density and large crystallization. Therefore, as the main raw material of magnesia carbon brick, magnesia quality indicators should consider the following content: 1. Magnesium oxide content (purity); 2. Types of impurities, particularly C/S and B2O3 content; 3. Magnesia density, stomatal aperture, stomatal morphology, etc. (sinterability).

The purity of magnesia has a great impact on the slag resistance of magnesia carbon brick. The higher the content of MgO, the less the impurity, the lower the division degree of silicate phase, the higher the direct binding degree of periclase, the increase the resistance to slag penetration and melting loss. The impurities of magnesia are mainly calcium oxide, silicon dioxide, iron oxide. If the impurities content is high, especially boron oxide compounds, will adversely affected the refractoriness and high temperature performance of magnesia. There have many kinds of refractory products in our factory. Such as fire brick for sale, refractory nozzle, refractory firebrick and other refractory products. Welcome to view our website to know more kinds of refractory products.
Article source: http://www.chinafirebrick.com/Company_News_111.html

Come to know the classification of refractory material

According to different chemical composition, refractory material can be divided into 3 types: alkaline, acid and neutral refractory material.

Alkaline refractory material: Generally refers to MgO or MgO and CaO as the main composition of refractory material. These refractory raw material have high refractoriness, with strong resistance to basic slag, and main are magnesia and dolomitic. Alkaline refractory materials are used in alkaline steel furnace, non-ferrous metal smelting furnace, cement industrial kiln, converter and electric arc furnace.

Acid refractory material: Usually refer to SiO2 content more than 93%. Its main feather is that it could resist the erosion of acidic slag at high temperature, but it is easy to react with alkaline slag, and it has poor thermal shock resistance. Main are siliceous, semi-siliceous, clay. Acid refractory material are mainly used in coke oven, glass kiln, acid steel furnace, etc.
Neutral refractory material: Refer to the refractory material which is not easy to react with acidic or basic slag, such as clay, high aluminum, carbon, chrome, mullite or corundum refractory material. Neutral refractory material are mainly used in blast furnace, aluminium cell, ferroalloy furnace, molten steel ladle, plating tank, autoclave and so on. There have many kinds of refractory products in our factory. Such as fire brick for sale, refractory nozzle, refractory castable, and so on. When you need any refractory products, welcome to view our website to know more.
Artilce source: http://www.chinafirebrick.com/Company_News_110.html