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.