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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 are refractory materials give some examples?
The typical refractory materials include fireclay refractories, high alumina refractories, silica brick, Magnesite refractories, Chromite refractories, Zirconia refractories, Insulating materials and Monolithic refractory.
What are refractories and its types?
TYPES OF REFRACTORIES On the basis of chemical nature: 1)Acid refractories 2)Basic refractories 3)Neutral refractories Based on fusion temperature: Normal refractory: fusion temperature of 1580 ~ 1780 °C (e.g. Fire clay) High refractory: fusion temperature of 1780 ~ 2000 °C (e.g. Chromite) Super Jun 28, 2018
What is a steel refractory?
A refractory material or refractory is a material that is resistant to decomposition by heat, pressure, or chemical attack, and retains strength and form at high temperatures. Refractory materials are used in furnaces, kilns, incinerators, and reactors.
What does refractory heart failure mean?
Refractory CHF is defined as symptoms of CHF at rest or repeated exacerbations of CHF despite “optimal” triple-drug therapy. Most patients with refractory CHF require hemodynamic monitoring and treatment in the intensive care unit.
What is a refractory symptom?
A refractory symptom is one that cannot be adequately controlled despite aggressive efforts to identify a tolerable therapy that does not compromise consciousness (Cherny 1994). A refractory symptom may be subjective and, at times, nonspecific.
What can I use instead of fire bricks?
Alternatives to Firebrick
- Ankar Sandstone. A sandstone type, ankar, is material which comes from a volcano.
- Red Clay Bricks. Simple red clay bricks can be utilized as another option in place of firebrick.
- Refractory Concrete. Refractory concrete is another choice for heat retention.
- Soapstone.
How many types of refractory bricks are there?
There are mainly three varieties of refractory bricks.
What are refractory gastrointestinal symptoms?
The symptoms of refractory disease are not unlike those of untreated celiac disease except that they are usually more severe and more disabling. The more common symptoms include weight loss, diarrhea, abdominal pain, malnutrition and anemia.
What is definition of refractory?
(Entry 1 of 2) 1 : resisting control or authority : stubborn, unmanageable. 2a : resistant to treatment or cure a refractory lesion.
How long is a refractory period?
The length of the refractory period varies greatly from person to person, from a few minutes to 24 hours, or longer.
What is the thickness of refractory lining in BOF?
This consist of a thinner safety lining to protect the shell usually of thickness ranging from 150 mm to 225 mm and a thicker working lining usually of thickness ranging from 450 mm to 750 mm.
What are the differences between refractories and insulators?
Refractory materials are diatomite products, asbestos products, thermal panels and so on. Insulation material is used for building envelope or thermal equipment, the heat transfer of the material or material complex, including both insulation materials, including cold materials.
What is refractory process?
Refractory manufacturing involves four processes: raw material processing, forming, firing, and final processing. Firing involves heating the refractory material to high temperatures in a periodic (batch) or continuous tunnel kiln to form the ceramic bond that gives the product its refractory properties.
What are refractory bricks used for?
A fire brick, firebrick, or refractory is a block of ceramic material used in lining furnaces, kilns, fireboxes, and fireplaces. A refractory brick is built primarily to withstand high temperature, but will also usually have a low thermal conductivity for greater energy efficiency.
What is firebrick 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
Which is a basic refractory?
Basic Refractory is refractory material contains magnesium oxide and calcium oxide. Basic refractory has high refractoriness and strong alkaline slag resistance. The major basic refractory is the refractory with the content of magnesia, dolomite and limestone.
How do you make refractory?
This process involves using an electric arc furnace to melt the refractory raw materials, then pouring the melted materials into sand-forming molds. Another type of refractory process is ceramic fiber production. In this process, calcined kaolin is melted in an electric arc furnace.
What is refractory period in biology?
In physiology, a refractory period is a period of time during which an organ or cell is incapable of repeating a particular action, or (more precisely) the amount of time it takes for an excitable membrane to be ready for a second stimulus once it returns to its resting state following an excitation.
Which is a special refractory?
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.
What is refractory pain?
Intractable pain or refractory pain occurs when pain cannot be adequately controlled despite aggressive measures.
What refractories are used in steelmaking?
Magnesia or Magnesia–Lime Group This group includes all refractories made from synthetic magnesites and dolomite. These constitute the most important group of refractories for the basic steelmaking processes. All these materials are used primarily as a source of magnesia (MgO).
What are refractories used for?
Refractories are ceramic materials designed to withstand the very high temperatures (in excess of 1,000°F [538°C]) encountered in modern manufacturing. More heat-resistant than metals, they are used to line the hot surfaces found inside many industrial processes.
What are the types of bricks?
- Sun-dried bricks: Unburnt bricks or sundried bricks are the first and most basic example of bricks.
- Burnt clay bricks:
- Fly ash bricks:
- Concrete Bricks:
- Engineering Bricks:
- Sand lime or calcium silicate Bricks:
- Porotherm Smart Bricks:
- Fire Bricks:
What are the characteristics of refractory materials?
Here are 10 common traits of refractory materials:
- Abrasion resistance.
- Bulk density.
- Cold crushing strength.
- Creep.
- Melting point.
- Porosity.
- Pyrometric cone equivalent.
- Refractoriness under load.
