The difference between insulation material and refractories

【China Aluminum Network】Insulation material refers to materials or material composites used for building enclosures or thermal equipment, and impedance heat flow transmission, including both thermal insulation materials and cold insulation materials. The heat-insulating material on the one hand satisfies the thermal environment of the building space or thermal equipment and on the other hand also saves energy. Therefore, some countries regard insulating materials as the “fifth largest energy source” after coal, oil, natural gas, and nuclear power. It has strong resistance to heat flow and is mainly used for insulation and heat insulation of walls, roofs, industrial pipes, kilns, etc. in house construction.

According to the principle of insulation is divided into:

1 Porous material. The gas with small thermal conductivity fills the insulation in the pores. Air is generally used as a heat-resistive medium, mainly fibrous aggregates and porous structural materials. Foam insulation is better, followed by mineral fibers (such as asbestos), expanded perlite, porous concrete, and foamed glass.

2 reflective material. For example, aluminum foil can reduce radiation heat transfer by heat reflection, and several layers of aluminum foil or composite structure with thin air layer sandwiched with paper can also increase the thermal resistance value. Insulation materials are often used in the form of loose materials, coils, plates, and prefabricated blocks for the insulation and thermal insulation of building roofs, exterior walls, and floors. It can be directly masonry (such as aerated concrete) or placed on the roof and enclosure structure as a core material, or it can be laid as a floor insulation layer. Fiber or granular heat insulation material can be filled in the wall, can also be sprayed on the wall, both insulation, sound absorption, decoration and fire-resistant effects.

There are many types of thermal insulation products, including foam plastics, mineral wool products, foam glass, expanded perlite thermal insulation products, EPS powder insulation slurry, mineral spray cotton, and foamed cement insulation products. Selection points: The type of application and design choice of insulation materials commonly used in buildings should comply with the requirements of GB/T17369-1998 “Application Types and Basic Requirements for Building Insulation Materials”. In addition to considering the thermal conductivity of the material, the water absorption, combustion performance, and strength of the material should also be considered. For the performance characteristics of different insulation materials, see the corresponding classification guide.

Refractory material refers to a class of inorganic non-metallic materials with refractoriness not lower than 1580°C. Refractoriness refers to the Celsius temperature of a refractory cone sample that resists high temperatures without softening the meltdown without loading. Refractory materials are widely used in metallurgical, chemical, petroleum, machinery manufacturing, silicate, power and other industrial fields, and they are used in large amounts in the metallurgical industry, accounting for 50% to 60% of the total output.

Frequently used special materials include AZS bricks, corundum bricks, direct bonded magnesium chrome bricks, silicon carbide bricks, silicon nitride bonded silicon carbide bricks, nitrides, silicides, sulfides, borides, carbides and other non-oxide refractory materials. ; Calcium oxide, chromium oxide, aluminum oxide, magnesium oxide, antimony oxide and other refractory materials. Frequently used refractory materials include diatomite products, asbestos products, heat insulation panels, and the like. Frequently used monolithic refractories include supplementary charge materials, refractory ramming mixes, refractory castables, fire-resistant plastics, fire-resistant mud, fire-resistant spray-welding materials, fire-resistant projectiles, fire-resistant paints, lightweight fire-resistant castables, and shot mud.

A wide range of refractory materials, usually divided according to the degree of refractoriness ordinary refractory (1580 ~ 1770 °C), high-grade refractory (1770 ~ 2000 °C) and special refractory (above 2000 °C); according to the chemical properties of acidic refractory materials, Neutral refractories and basic refractories. In addition, there are refractory materials for special occasions.

Acid refractories are mainly composed of silica, commonly used are silica bricks and clay bricks. Silica bricks are silicon products containing more than 93% silicon oxide. The raw materials used are silica, waste silica bricks, etc. The acid-resistant slag has strong erosion resistance, and the softening temperature of the load is high. The volume does not shrink after repetitive calcination and even slightly expands. However, it is vulnerable to alkaline slag and has poor thermal shock resistance. Silicon bricks are mainly used in coke ovens, glass melting furnaces, acid steelmaking furnaces and other thermal equipment. The clay brick is mainly made of fire-resistant clay and contains 30% to 46% of alumina. It is a weakly acidic refractory material with good thermal shock resistance and corrosion resistance to acid slag. It is widely used.

Neutral refractories are mainly composed of alumina, chrome oxide or carbon. The corundum product containing more than 95% alumina is a kind of high-quality refractory material with wide application. Chromium bricks with chromium oxide as the main component have good corrosion resistance to steel slag, but have poor thermal shock resistance and low load deformation temperature at high temperature. Carbonaceous refractories are carbon bricks, graphite products and silicon carbide products, which have a low coefficient of thermal expansion, high thermal conductivity, good heat and vibration resistance, high temperature strength, resistance to acid and alkali and salt, free from metals and slags. Wetting, light weight. Widely used as high-temperature furnace lining material, also used as oil, chemical industry autoclave lining.

Basic refractory materials are mainly composed of magnesium oxide and calcium oxide. Magnesia brick is commonly used. Magnesium oxide bricks containing 80% to 85% of magnesium oxide have good resistance to alkaline slag and iron slag, and have higher refractoriness than clay bricks and silica bricks. Mainly used in open hearth, oxygen blowing furnace, electric furnace, non-ferrous metal smelting equipment and some high temperature equipment.

Refractory materials used in special applications include high-temperature oxide materials such as alumina, yttrium oxide, yttrium oxide, calcium oxide, zirconium oxide, etc., and refractory compound materials such as carbides, nitrides, borides, silicides, and sulfides. Etc.; high-temperature composite materials, mainly cermets, high-temperature inorganic coatings and fiber-reinforced ceramics.

CNC Mini Carbide End Mills

Application:for Metal Stainless Steel Miling

1.Mainly used for machining round headed flat key seats, Also used to work open grooves, some are used for insertion milling, drilling. Suitable for milling grooves with width requirements. Spiral-teethed structure ensures smooth cutting.

1.Mainly used for machining round headed flat key seats, Also used to work open grooves, some are used for insertion milling, drilling. Suitable for milling grooves with width requirements. Spiral-teethed structure ensures smooth cutting.
2.Having an excellent self-centering capability, can processing H7 wor k piece efficiently.
3.Processed holes can achieve high position and have a good straightness and surface finish.
4.For materials with short chips such as cast iron, silicon-aluminum alloy, etc
5.Designed for a general performance to carbon steel ,tool steel, alloy steel and stainless steel
6.Roughing end mills allow for heavier cuts and remove more material.

Cnc Mini Carbide End Mills,Mini Sinking Cutter For Metal,Solid Carbide Diamond End Milling Cutter,Mini Diy Modeling Tools For Driller

Changzhou Bomitools Co.,Ltd. , https://www.bomitools.com