Which type of _______________ bricks exhibits an exceptionally low linear thermal expansion of ≤ 0.5 percent up to 1000 °C?
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Answer: A. Fireclay
Explanation
Fireclay bricks demonstrate an exceptionally low linear thermal expansion of less than or equal to zero point five percent up to one thousand degrees Celsius. This minimal dimensional change helps maintain tight masonry structures and prevents severe thermal stress during heating cycles. The stable alumino-silicate crystal matrix absorbs thermal energy without undergoing disruptive phase volume transformations. Linear thermal expansion measures the percentage increase in length of a refractory brick when heated to a specific temperature. Fireclay refractories contain moderate amounts of alumina and silica, resulting in stable thermal expansion characteristics. Low thermal expansion is a highly desirable property for bricks used in cyclic industrial heating and cooling applications.
Option B describes silica bricks, which exhibit much higher and more erratic thermal expansion below six hundred degrees Celsius. Option C refers to magnesite bricks, which generally display higher thermal expansion coefficients than standard fireclay. Option D lists corundum, which has high alumina purity and different thermal expansion properties compared to fireclay.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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