Question

Silica bricks show good thermal shock resistance above

• A. \(600^\circ C\)
• B. \(800^\circ C\)
• C. \(400^\circ C\)
• D. \(900^\circ C\)

Hint:

Silica bricks should be heated and cooled carefully at low temperatures, but they show good thermal shock resistance above about \(600^\circ C\).

Answer 1

The Correct Option is A

Silica bricks are made mainly from silica. Silica undergoes different phase changes with temperature. At lower temperatures, these phase transformations can cause volume changes. Because of these volume changes, silica bricks may be sensitive to thermal shock at lower temperature. However, above a certain temperature, silica bricks become more stable in service. They show good thermal shock resistance above: \[ 600^\circ C. \] This is why silica bricks are often used in applications where the operating temperature remains high and temperature fluctuation through low-temperature ranges is avoided. Therefore, the correct answer is: \[ 600^\circ C. \]