What are Refractories?
To put it simply, refractory is any material that has the ability to withstand the action of abrasive or corrosive solids, liquids or gases at high temperatures. Depending upon the application areas and operating conditions, a refractory company can come up with a line of refractory products in varying combinations and shapes, such as refractory bricks for cement plant, fire clay bricks, high alumina bricks, special quality bricks, low cement castables, special castables, and ramming masses & mortars.
General requirements of a refractory product are:
It can withstand high temperatures
It can withstand sudden changes of temperatures
It can withstand load and abrasive forces
It can withstand action of molten metal slag, glass, etc.
It should not contaminate the material (or, materials) with which it comes into contact
Some of the essential properties of refractories include:
Melting Point: Refractory materials are high temperature materials, and this property makes them ideal for various applications in iron, steel, and glass industries. Since pure substances tend to melt in no time at a specific temperature, the refractories industry manufacture materials, which consist of particles bonded together that have high melting temperatures. As far as the melting point of a refractory product is concerned, it is that temperature at which a test pyramid (cone) fails to support its own weight.
Size: Refractories industry manufactures refractory products of various shapes and sizes depending upon the user industry and application areas. Accurate size (of the product) is extremely important to properly fit the refractory shape inside the furnace.
Creep at High Temperature: It is one very essential property (of refractories), which determines the deformation in a given time (and at a given temperature) by a refractory product under stress.
Bulk Density: Bulk density refers to the amount of refractory material within a volume (kg/m3). It has a direct impact on a refractory product's volume stability, heat capacity, and resistance to slag penetration.
Cold Crushing Strength: It is a refractory product's resistance to crushing, which usually happens during transport. The cold crushing strength only has an indirect relevance to refractory performance, and is used as an indicator of abrasion resistance of the material.
Whether it is a steel plant, or cement plant, or any other manufacturing plant, failure of refractory could result in a significant loss of production time, and equipment; in fact, the product itself could be at risk; therefore, obtaining and using refractory products best suited to each application in the plant is of supreme importance.
