The usage and use of refractories are different due to different material types, product forms and application fields. The following is a detailed introduction of the main ways and uses of refractories:

I. Usage of Refractory Materials

(1) the use of shaped refractories

Refractory bricks:

Masonry method: Refractory bricks usually adopt dry masonry or wet masonry. Dry-building is to pile bricks together directly, which is suitable for some parts that do not need high-strength sealing; Wet masonry requires the use of refractory slurry (such as phosphate slurry, sodium silicate slurry, etc.) to bond the bricks together to enhance the stability and sealing of the structure.

Construction requirements: In the process of masonry, the construction should be carried out in strict accordance with the design requirements to ensure the uniformity and compactness of brick joints. Brick joints should generally be controlled between 1 and 3 mm to prevent the penetration of high-temperature gas or slag.

Application scenario: Refractory bricks are mainly used for lining of high-temperature furnaces, such as iron-making blast furnace, steel-making converter, glass melting furnace, cement rotary kiln and so on.

Insulating brick:

Installation method: insulating brick usually adopts dry masonry method, which is directly stacked on the furnace wall or roof. Insulating brick can be used together with refractory bricks to form a composite lining structure in some parts that need higher thermal insulation effect.

Construction requirements: The installation of insulating brick needs to ensure the close contact between bricks and avoid gaps. At the same time, the surface of insulating brick needs to be flat to reduce heat loss.

Application scenario: insulating brick is mainly used to reduce heat loss of furnace wall and improve energy utilization efficiency, and is widely used in furnace wall, roof and flue of various high-temperature furnaces.

(2) the use of unshaped refractories

Refractory castable:

Construction method: refractory castable needs to be stirred and poured on site. Firstly, the refractory aggregate, powder and binder (such as aluminate cement, aluminum dihydrogen phosphate, etc.) are mixed evenly in proportion, and then a proper amount of water or other liquid is added and stirred into slurry. Finally, the slurry is poured into the mold, and the refractory structure is formed after curing and baking.

Construction requirements: it is necessary to ensure the uniformity and fluidity of the slurry during pouring, and avoid the occurrence of air holes and honeycomb structures. After pouring, it is necessary to properly maintain and bake the pouring body to ensure its strength and performance.

Application scenario: refractory castable is widely used for lining of various high-temperature furnaces, such as ladle, tundish, heating furnace, tunnel kiln and so on. It is especially suitable for the parts with complex shapes or needing on-site construction.

Plastic refractory:

Construction method: plastic refractory is a kind of plastic refractory material, which can be molded manually or mechanically on site. During construction, the plastic refractory is kneaded into the required shape, and then pasted or laid on the furnace wall.

Construction requirements: The construction of plastic refractory needs to ensure the uniformity and compactness of materials and avoid cracks and gaps. After the construction is completed, it is necessary to bake plastic refractory properly to improve its strength and fire resistance.

Application scenario: plastic refractory is mainly used to repair and maintain the lining of high-temperature furnaces, such as local damaged parts of furnace walls, furnace doors and furnace covers.

High temperature refractory mud:

Construction method: High-temperature refractory mud is mainly used for filling brick joints when building refractory bricks. During construction, the refractory mud is daubed in the brick joints, and then the bricks are compacted to ensure the compactness of the brick joints.

Construction requirements: the construction of refractory mud needs to ensure the uniformity and fullness of brick joints and avoid gaps and cracks. At the same time, the composition of refractory mud needs to match the composition of refractory bricks to ensure the overall fire resistance.

Application scenario: High-temperature refractory mud is widely used for refractory brick masonry in various high-temperature furnaces, such as blast furnace, converter and glass melting furnace.

II. Use of Refractory Materials

(1) Metallurgical industry

Iron-making blast furnace: the lining of blast furnace usually adopts magnesia brick or magnesia-alumina spinel brick, which has good corrosion resistance and thermal shock resistance and can withstand the erosion of high-temperature molten iron and slag.

Steelmaking converter: The lining of converter mainly uses high alumina brick or magnesia-carbon brick. High alumina brick has good corrosion resistance, while magnesia-carbon brick has excellent thermal shock resistance and slag resistance, which can effectively prolong the service life of furnace lining.

Ladle and tundish: The lining of ladle and tundish is usually made of refractory castable or precast block, and these materials need to have good corrosion resistance and thermal shock resistance to withstand the erosion and temperature change of high-temperature molten steel.

(2) Petrochemical industry

Petroleum cracking furnace: The furnace tube and furnace wall of cracking furnace are usually made of high alumina bricks or mullite brick, which can withstand high temperature and chemical reaction.

Catalytic cracking unit: The regenerator and reactor lining of catalytic cracking unit usually use refractory castable or ceramic fiber modules, which have good thermal insulation and chemical corrosion resistance.

(3) Building materials industry

Cement rotary kiln: the lining of cement rotary kiln usually adopts high alumina brick or magnesia-alumina spinel brick, which can withstand high temperature and chemical erosion of clinker.

Glass melting furnace: refractory bricks and ceramic fiber products are usually used in the lining of glass melting furnace, which can ensure the uniform melting and molding of glass.

(4) Other fields

Foundry industry: The sand molds and gating systems used in the casting process are usually made of refractory materials to ensure the smooth flow and molding of molten metal.

Mechanical processing industry: In heat treatment furnaces and forging furnace, refractory materials are used to protect furnace lining to withstand high temperature and mechanical impact.

Military field: Refractory materials are used for heat insulation protection of high-temperature components such as missiles and rocket engines to ensure their normal operation in high-temperature environment.

III. summary

The way and use of refractories vary according to the type of materials and application fields. Shaped refractory materials such as refractory bricks and insulating brick are mainly used for lining of high-temperature furnaces, and they need to be laid or installed in strict accordance with the design requirements during construction; Irregular refractory materials such as refractory castable, plastic refractory and high-temperature refractory mud have higher flexibility and are suitable for complex parts or site construction. Refractory materials are widely used in metallurgy, petrochemical industry, building materials, casting, mechanical processing and military and other fields, providing a reliable guarantee for high-temperature industry.