Difficulty: Easy
Correct Answer: All of the above
Explanation:
Introduction / Context:
Refractory materials such as firebricks and silica bricks are essential for high-temperature structures including furnaces, kilns, and chimneys. Understanding their key properties—water absorption, chemical composition, and compressive strength—enables appropriate selection and specification for thermal and mechanical performance in service.
Given Data / Assumptions:
Concept / Approach:
Firebricks are designed to withstand high temperatures and thermal cycling; their absorption usually lies within controlled limits (about 5%–10%) to minimize spalling. Silica bricks are characterized by very high silica content (around 95%–97%) with minor additions—commonly lime (about 1%–2%)—to aid bonding and sintering. Their compressive strength values are moderate compared with structural stones or concretes but adequate for refractory linings, often quoted around 150 kg/cm^2 in exam-oriented data sets.
Step-by-Step Solution:
Verification / Alternative check:
Multiple handbooks on refractory bricks corroborate these indicative ranges, noting that precise values vary with formulation and firing schedules.
Why Other Options Are Wrong:
Each individual statement stands on its own; hence the combined option is correct.
Common Pitfalls:
Expecting structural-level compressive strengths from refractories; assuming zero water absorption; ignoring that small lime additions serve as binders in silica compositions.
Final Answer:
All of the above
Discussion & Comments