This section introduces the types and physical properties of refractories.

One. What is Refractory?

Refractory materials generally refer to the above-mentioned inorganic non-metallic materials with a fire resistance of 158 °C. It includes natural ores and a variety of products that are made by a certain process according to the requirements of a certain purpose. It has certain high-temperature mechanical properties. It has good volume stability and is a necessary material for various high-temperature equipment. It is widely used.

Two. Types of refractories

1. Acid refractory usually refers to SiO2. refractory material content is greater than 93%, and its main feature is that it can resist the erosion of acid residue at high temperature, but it is easy to react with alkali residue. Silica bricks and clay bricks are often used for acid refractories. Silica brick is a silicon product containing more than 93% silicon oxide. Waste silica bricks have strong acid resistance, high softening temperature, high softening temperature after repeated calcination, and no shrinkage of volume after repeated calcination, or even slightly expanded; However, it is susceptible to alkaline slag erosion and poor heat resistance. Silica bricks are mainly used in coke ovens. Glass melting furnace. Thermal equipment such as acid steelmaking furnaces. Clay bricks are made of refractory clay as the main raw material, containing 30%~46% alumina. It is a weakly acidic refractory material with good thermal vibration resistance and corrosion resistance.

2. Alkaline refractories generally refer to refractories with magnesium oxide or magnesium oxide and calcium oxide as the main components. This refractory material has high fire resistance and strong resistance to alkali slag. For example, magnesia bricks. Magnesia chrome bricks. Chrome magnesia bricks. Magnesia aluminum bricks. Dolomite bricks. forsterite bricks, etc. It is mainly used in alkaline steelmaking furnaces. Non-ferrous metal smelting furnaces, cement kilns, etc.

3. Aluminum silicate refractory refers to SiO2-Al2O3, according to the content of its main component of refractory Al2O3, it can be divided into semi-siliceous (Al2O315~30%), clay (Al2O330~48%), high alumina (Al2O three categories greater than 48%).

4. Cast refractory refers to refractory products that are melted with materials at high temperature and poured into a certain shape.

5. Neutral refractories refer to refractory materials, such as carbon refractories and chromium refractories, which are not easy to react significantly with acidic or alkaline slag at high temperatures. Some people also classify high-alumina refractories as such materials.

6. Special refractories are new inorganic non-metallic materials developed on the basis of traditional ceramics and general refractories.

7. Amorphous refractory material is made of refractory aggregate and powder. Mixtures consisting of a certain percentage of binders or other additives can be deployed directly or with an appropriate liquid. Amorphous refractory is a new type of refractory material that is not calcined, and the fire resistance is not less than 1580 °C.

Three. What are the commonly used refractories?

Silica brick is a commonly used common refractory material. Semi-silica brick. Clay bricks. High alumina bricks. magnesia bricks, etc.

Commonly used special materials are AZS bricks. Corundum bricks. Magnesia chrome bricks are directly combined. Silicon carbide bricks. Silicon nitride is combined with silicon carbide bricks, nitride. Silicide. Sulfide. Boride. non-oxide refractories such as carbides; Calcium oxide. Chromium oxide. Alumina. Magnesium oxide. Refractory materials such as beryllium oxide.

Diatomaceous earth products are commonly used thermal insulation refractory materials. Asbestos products. insulation panels, etc.

Commonly used amorphous refractories are charges. Refractory ramming material. Refractory casables. Refractory plastic. Refractory mud. Refractory gunning material. Refractory projection