Refractory Technology
Carbon refractories

Do not burn/oxidise, when exposed to air on heating
Have extremely low thermal & electrical conductivities
Are not attacked by slags, as they are not wetted by melts
Do not resist temperature fluctuations

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Refractory Technology
Fireclay refractories

Shrink during firing
All of these
Combine with salts (e.g. chlorides sulphates etc.) & bases (e.g. lime, magnesia etc.) forming fusible aluminates silicates etc
Are not resistant to the action of basic slags

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Refractory Technology
Natural silica

Transforms to other allotropic forms i.e tridymite and cristoballite involving very high volume changes
Mainly contains quartz
All of these
Is not stable at high temperature

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