What are the types of refractories?
Last Update: May 30, 2022
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Asked by: Pattie Hayes
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- Fireclay refractories. ...
- Silica brick. ...
- High alumina refractories. ...
- Magnesite refractories. ...
- Chromite refractories. ...
- Zirconia refractories.
How many types of refractory are there?
Insulating refractories can be further classified into four types: Heat-resistant insulating materials with application temperatures ≤ 1100 °C. Refractory insulating materials with application temperatures ≤ 1400 °C. High refractory insulating materials with application temperatures ≤ 1700 °C.
What are the three classification of refractories?
Accordingly to this classification, refractories are of three types namely (i) acid refractories, (ii) basic refractories, and (iii) neutral refractories. Also there are some special types of refractories. Acid refractories – These refractories are attacked by alkalis (basic slags).
What are basic refractories?
Basic refractories consist of minerals like lime (CaO) and magnesia (MgO) and can be used in basic like environments. Neutral refractories usually contain varying amounts of chrome in several forms in combination with alumina or magnesia and work well in the middle of the acid / base spectrum.
What are refractories used for?
Fire clay refractories: They are mostly consumed by steel industries. They are widely used in foundries as well. Magnesium Refractories: Mainly used in the steel industry for the lining of basic converters and open-hearth furnaces. Dolomite refractory: generally used as a repair material.
What Are Refractories ??? Types Of Refractories / Ceramic Materials / Material Science
What are the characteristics of refractories?
- Abrasion resistance.
- Bulk density.
- Cold crushing strength.
- Melting point.
- Pyrometric cone equivalent.
- Refractoriness under load.
What are the properties of refractories?
Important properties of refractories include chemical composition, bulk density, apparent porosity, apparent specific gravity and strength at atmospheric temperatures. These properties are frequently among those which are used as 'control points' in the manufacturing and quality control process.
What are special refractories?
Special refractories mainly include high melting point oxides, high melting point non-oxides, and the derived composite compounds, cermet, high-temperature coating, high-temperature fiber, and reinforcing materials.
How refractories are selected explain?
Refractories should have stable volume at high temperature and the residual expansion and contraction should be small. Heat capacity, thermal expansion coefficient, thermal conductivity and other thermal properties should meet the requirements. Refractories should have neat appearance and accurate shape and size.
What are super refractories?
Refractory is a material that will retain its shape and chemical identity when subjected to high temperatures and is used in applications that require extreme resistance to heat, such as furnace linings. Refractory products are basically used in industries for heat resistant and containment.
What are the general requirements of a refractory material?
The general requirements of a refractory material can be summed up as: 1) Its ability to withstand high temperatures and trap heat within a limited area like a furnace; 2) Its ability to withstand action of molten metal , hot gasses and slag erosion etc; 3) Its ability to withstand load at service conditions; 4) Its ...
What are acid refractories?
Acid refractories are those which are not attacked or affected by acidic materials, but easily attacked by alkalis (basic slags). These are used in areas where slag and atmosphere are acidic. Acid refractories include substances such as zirconia (ZrO2), alumina (Al2O3), silica (SiO2) and fire clay brick refractories.
What is the refractory industry?
Refractories are ceramic materials that are essential for all high-temperature industrial processes because they provide mechanical strength, protection against corrosion, and thermal insulation. ... The WRA video below details the industry's impact in more depth.
How many types of refractory bricks are there?
There are mainly three varieties of refractory bricks.
What is a refractory patient?
(reh-FRAK-tor-ee) In medicine, describes a disease or condition that does not respond to treatment.
What is refractory and its types?
The typical refractory materials include fireclay refractories, high alumina refractories, silica brick, Magnesite refractories, Chromite refractories, Zirconia refractories, Insulating materials and Monolithic refractory.
What is refractory raw material?
Minerals commonly used for refractories include (but are not limited to) alumina, bauxite, graphite, kaolin, magnesia and zirconium. These minerals are produced globally but, in some cases, not always of grades suitable for refractory applications (e.g., alumina and bauxite).
What are refractory minerals?
Refractory minerals can be defined as minerals or synthetic inorganic crystal phases that have high melting points. They should also be resistant to deformation and to softening at high temperatures. ... Refractories are usually classified as acid, basic, or other.
What do you mean by refractory material?
Refractories are materials that are resistant to high temperature, used predominantly as furnace linings for elevated temperature materials processing and other applications in which thermomechanical properties are critical.
What is a refractory liner?
A refractory lining usually comprises a safety or backup layer behind the working lining in contact with the furnace contents. The whole body is encased in a metal shell. The temperature gradients in the system and the properties of all materials must be considered.
What is a good refractory material?
The most common basic refractories are Magnesite, Dolomite, lime etc. But lime, because of its dehydrating tendency is never used as a refractory. Magnesite: This is most important basic refractory material.
What are the requirements of good Refractories?
A good refractory should have high RUL value. It is defined as the ratio of its pore volume to the bulk volume. Porosity is an important property of refractory bricks, because it affect many other characteristics like chemical stability, strength, abrasion- resistance and thermal conductivity.
What do you mean by Rul test?
Refractoriness under load (RUL) is a measure of the deformation behavior of refractory ceramic products subjected to a constant load and increasing temperature. ... The creep in compression test is also carried out in the RUL 421 to a maximum temperature of 1700 °C.
What are refractory bricks made of?
Principal raw materials for firebrick include fireclays, mainly hydrated aluminum silicates; minerals of high aluminum oxide content, such as bauxite, diaspore, and kyanite; sources of silica, including sand and quartzite; magnesia minerals, magnesite, dolomite, forsterite, and olivine; chromite, a solid solution of ...
What is refractory in steel industry?
Refractories are the essential lining materials for working interfaces and backup zone of furnaces during manufacturing of iron and steel, in specific sequential and consecutive operation of forming, holding, mixing and transporting hot metal, liquid steel and slag.