efractory degree not lower than 1580℃ a kind of inorganic non metallic materials.Refractoriness is refractory cone specimen under no load condition, resistance to high temperature without softening melting down of the Celsius temperature. But only the refractoriness to define cannot fully describe the refractory material, the temperature of 1580℃ is not absolute. Is defined as any physical and chemical properties allow its use in the environment of high temperature materials called refractory material.
Refractory materials are widely used in metallurgy, chemical, petroleum, machinery manufacturing, silicate, power and other industrial fields, the largest amount in the metallurgical industry, the total yield of 50% ~ 60%.
There are varieties of refractory materials, use of different, it is necessary to carry out the scientific classification of refractory material, in order to facilitate scientific research, reasonable selection and management.
Many classification methods of refractory materials, including the classification, the chemical properties of the chemical and mineral composition of classification, production process, material classification methods such as morphological classification.
according to the degree of division of refractory:
Common refractory: 1580 to 1770 ℃
Advanced refractory materials: 1770 to 2000 ℃
Special refractory material: >2000 ℃
according to the different shape and size of the products:
Standard type: 230mm * 113mm * 65mm;
No more than 4 scale, (size ratio) Max:Min<4:1;
Different type: no more than 2 recesses, (size ratio) Max:Min<6:1;
There is an acute angle or a 50 to 70 degree;
Specific type: (size ratio) Max:Min<8:1;
Or not more than 4 concave; or an acute angle with a 30 to 50 degree;
Special products: the crucible, containers, pipes etc..
by the way of making refractory materials can be divided into:
Burnt product, not burning products, unshaped refractory materials
according to the chemical properties of the material classification:
Acid refractory material, refractory materials, basic refractories
According to the mineral composition of 5 chemical classification
To directly characterize various refractory materials. The basic composition and characteristics of this kind of classification, in the production, use, scientific research is the classification of common, has a strong practical significance.
Magnesia, magnesium, aluminum magnesium, calcium magnesium silicon
Carbon composite refractory
Special refractory material
classification of unshaped refractory materials (classification according to the method of use)
Press the material
The dry vibration material
Self flow castable
Acid refractory material with silicon oxide as the main ingredient, commonly used are Silica Brick and clay. Silica is silica products, silica containing more than 94%, raw materials used in silica, silica and other waste
the acid resistance of slag erosion ability, high refractoriness under load, the volume does not shrink after repeated burning, or even a slight expansion; but vulnerable to the erosion of basic slag, thermal shock resistance difference. Mainly used for thermal equipment of coke oven Silica Brick, glass kiln
acidic steelmaking furnace etc.. Clay brick with refractory clay as the main raw material, containing 30% ~ 46% of alumina, is a weak acid refractory material, heat shock resistance is good, there is resistance to acidic slag, wide application.
Neutral alumina refractories, chromium oxide or carbon as the main component. Containing more than 95% of alumina corundum products high quality refractory materials is a wider use of the.
Chrome brick by using chromium oxide as the main component of the corrosion resistance of steel slag is good, but the poor thermal shock resistance, high temperature load deformation temperature is low.
Carbon refractories with carbon bricks, graphite and silicon carbide products, its thermal expansion coefficient is very low, high thermal conductivity, good thermal shock resistance, high temperature strength, resistance to acid and salt corrosion, especially the weak acid has better ability to resist, not affected by the wettability of metal and slag, light. Widely used in high temperature furnace lining material, is also used in petroleum, chemical autoclave liner.
Refractory to Magnesium Oxide, calcium oxide as the main ingredient, is commonly used in Magnesia Brick. Magnesia Brick containing Magnesium Oxide 80% ~ 85% more, has the very good resistance to alkali slag and iron slag, refractory degrees than Silica Brick clay brick and high. Mainly used in open hearth furnace, oxygen blown converter, electric furnace, non-ferrous metal smelting equipment and some high temperature equipment.
High temperature oxide material in refractory applications of special occasions, such as aluminum oxide, lanthanum oxide, beryllium oxide, calcium oxide, zirconium oxide, hard materials melting compounds, such as carbides, nitrides, borides, silicides and sulfides; high temperature composite materials, mainly metal ceramic, high temperature inorganic coatings and fiber reinforced ceramics.
AZS refractories are often used brick, corundum brick, magnesia chrome brick directly, silicon carbide, silicon nitride bonded silicon carbide, nitride, boride, silicide, sulfide, carbide and other non oxide refractory materials; calcium oxide, chromium oxide, alumina, Magnesium Oxide, beryllium oxide refractory.
Insulating refractory materials are often used diatomite products, asbestos products, heat insulation board.
Unshaped refractory materials commonly used are fettling, ramming material, pouring material, plastic, fireclay, refractory gunning material, refractory cast material, fireproof coating, lightweight refractory castable, stemming etc..
Powdered refractory material (unshaped refractory materials): unshaped refractory material, refractory material co is composed of reasonable distribution in the granular and powdered materials and the binder not forming and firing directly for the use of the.
Usually, the composition of granular material this material known to aggregate, powder material called admixtures, on the bond said cementing agent. This kind of material has no fixed shape, can be made into slurry, mud paste and loose, which is also known as the powdered refractory material. The use of such refractories can constitute the whole without seam structures, so it is also called monolithic refractory.
Monolithic refractories is the basic component of granular and powdered refractory materials. According to the use requirement, can be made of various materials. In order to make these refractory material combination as a whole.
with the exception of a few special cases, bond generally add the appropriate variety and quantity of. In order to improve the plasticity or reduce water use, can add a few appropriate plasticizing water reducing agent, to meet other special requirements, can also add a small amount of other appropriate admixture respectively.