Refractory Technology
Natural silica

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

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Refractory Technology
Silica refractories

Can not be used in the dome of hot blast stoves
Crack when subjected to sudden change of temperature
All of these
Have lower thermal conductivity than fireclay bricks

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