What are the classification of refractories?

What are the classification of refractories?

Refractories may be classified by thermal conductivity as either conducting, nonconducting, or insulating. Examples of conducting refractories are SiC and ZrC, whereas examples of nonconducting refractories are silica and alumina. Insulating refractories include calcium silicate materials, kaolin, and zirconia.

What is refractories in civil engineering?

Refractories are essentially non-metallic construction materials which are capable of retaining their form and strength at extremely high temperatures, under varying conditions of mechanical stress and chemical attack by hot gases, liquids, or molten and semi-molten materials such as glass, metals or slags.

What are the characteristics 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 basic refractories?

Basic shaped refractories are those refractories which have resistance to corrosive reactions with chemically basic slags, dusts and fumes at elevated temperatures. They are both MgO and CaO based refractories or in combination between them or in combination between MgO and Cr2O3.

What is refractory manufacturing?

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 three different types of refractories?

Depending on temperatures and service conditions of the applications such as boilers, furnaces, kilns, ovens etc, different types of refractories are used.

• Fireclay refractories.
• Silica brick.
• High alumina refractories.
• Magnesite refractories.
• Chromite refractories.
• Zirconia refractories.

What are the properties of good refractory material?

Properties Of Refractory Materials

• Bulk density. It is a general indication of product quality.
• Porosity. It is defined as the ratio of its pores volume to its total volume.
• Cold compressive strength.
• Flexural strength.
• Wear resistance.

What is refractories and three characteristics?

Refractories are heat-resistant materials that constitute the linings for high-temperature furnaces and reactors and other processing units. In addition to being resistant to thermal stress and other physical phenomena induced by heat, refractories must also withstand physical wear and corrosion by chemical agents.

What is neutral refractory?

i. A refractory that is neither strongly basic nor strongly acid, such as chrome, mullite, or carbon. Ref: ARI. ii. A refractory that is resistant to chemical attack by both acid and basic slags, refractories, or fluxes at high temperatures.

What is refractory cement?

Refractory cement uses binding materials with improved thermodynamic properties to reduce the risk of mechanical failure. Fused minerals like aluminum oxide, or alumina, are used to bind coarse aggregate materials and provide superior temperature resistant properties without reducing the formability of the material.

What is refractory in steel industry?

Refractories are used by the metallurgy industry in the linings of furnaces, kilns, reactors and other vessels for holding and transporting metal and slag. Due to the extremely high melting point of common metals like iron, nickel and copper, metallurgists have to raise furnace temperatures to over 2800°F.