What are the properties and significance of Fire Clay?

Hello,

Let’s discuss the definition of fire clay:

Fire clay is a range of refractory clays used in the manufacture of ceramics, especially for fire brick.

The United States Environmental Protection Agency defines fire clay as a “Mineral aggregate composed of hydrous silicates of aluminum (Al2O3.SiO2.2H2O) with or without silica.”

Properties of fire clay:

• Natural water content – 12%
• Moisture absorption – 6.8%
• Minus No.200 sieve size – 87%
• Loss of ignition – 10.6%
• Specific gravity – 2.66
• Loss of ignition – 7.4%
• Liquid limit – 35%
• Plastic limit – 19%
• Plasticity index – 16%
• Drawing shrinkage – 4.8%
• Fired shrinkage – 16.2%
• Maximum dry density – 1.83 Mg/m cube.
• Optimum moisture content – 12.3%
• Shear strength – 180 KN per metre square
• The angle of internal friction – 29.6 degree
• Ultrasonic pulse velocity – 2.1 km/s
• Uniaxial compressive strength – 22 MPa

Significance of fire clay :

• Fire clay has attractive qualities as refractory raw material.
• It is more abundant and cheap material
• Extensively used in all places like glass melting furnaces, boiler furnaces, Chimney linings, pottery kilns, blast furnaces and reheating furnace.
• The refractoriness and other qualities of the clay as a refractory raw material can be improved by the addition of Bauxite a common practice in industries.
• The rhythmically changing properties of the coalfield cyclothem can pose some foundation problems arising from inter bedding of soft and hard layers.

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Fire clay :-

Fire clay is a range of refractory clays used in the manufacture of ceramics, especially fire brick. The United States Environmental Protection Agency defines fire clay very generally as a “mineral aggregate composed of hydrous silicates of aluminium (Al2O3·2SiO2·2H2O) with or without free silica.”

Properties of fire clay :-

Fire clay is resistant to high temperatures, having fusion points higher than 1,600 °C (2,910 °F); therefore it is suitable for lining furnaces, as fire brick, and for manufacture of utensils used in the metalworking industries, such as crucibles, saggars, retorts and glassware. Because of its stability during firing in the kiln, it can be used to make complex items of pottery such as pipes and sanitary ware.

Fire clay bricks

Fire bricks or fire clay bricks are made from the fire clay. The process of manufacturing of these bricks is same as the ordinary bricks but are burnt at very high temperatures in a special type of kilns generally Hofmann’s kill. The raw materials of these bricks consists of flint clay and grog that has burned fire clay as non plastic materials and soft fire clay as plastic material.

Properties

• Color of these bricks is whitish-yellow or light brown.
• Comp strength of fire clay bricks varies from 3.5 N/mm2 to 48.26 N/mm2.
• The water absorption % of fire bricks varies from 4 – 10%.
• These bricks are generally used in lining furnaces kilns, fire boxes and fireplaces.

Hi, Advantages of the Fire Clay Bricks:

1. Low porosity and strong density.
2. Good penetration resistance and good erosion resistance.
3. High-temperature stability and long life.
4. the fire clay bricks used as the refractory lining in the interpreting thermal furnaces.
5. As per uses of fire clay bricks, it is divided into fire clay bricks for blast furnaces, fire clay bricks for hot blast stoves, large fire clay bricks for glass kilns, etc

Disadvantages

1. Weight is more. Not sure about labour cost compared to other materials but would least slightly higher.
2. Bricks are made of clay, not soil. Clay is an element of soil. The pollution occurs due to fabricating the brick due to the burning of fuels.
3. The bricks can be converted or pulverized into sand type materials.
4. It requires an additional stucco, that is strictly for glimpses.

Brick is a great building material as long as it is appropriately used either or alone with supplementary materials.

Properties and significance:

1. It can withstand a temperature of at least 1515 °C.
2. It is made up of 65% siliceous materials and 22% argillaceous materials.
3. It has high alumina content and kaolinite.
4. It is plastic in nature and have high iron impurities.
5. It is ideal for lining surfaces exposed to high temperature.
6. It is used in furnaces, kilns, in manufacture of crucibles, fire bricks, saggars and glassware.