Periclase refractories: the principal constituent oxide in periclase-based bricks is which of the following?
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ACaO
-
BMgO
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CAl2O3
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DSiO2
-
EZrO2
Answer
Correct Answer: MgO
Explanation
Introduction / Context:Periclase is the mineral form of magnesium oxide and gives its name to MgO-based refractory bricks. These basic refractories are vital in metallurgical vessels exposed to basic slags, where chemical compatibility controls lining life.
Given Data / Assumptions:
- Periclase refers specifically to crystalline MgO.
- Common applications include steelmaking furnaces and cement kilns.
Concept / Approach:Refractory nomenclature often maps directly to the dominant phase: “periclase” → MgO; “corundum” → Al2O3; “silica” → SiO2; “zirconia” → ZrO2. Recognizing these links helps quickly identify chemical compatibility with slags and atmospheres.
Step-by-Step Solution:Note that periclase is MgO.Therefore, periclase refractories are primarily MgO-based.Select MgO.
Verification / Alternative check:Phase diagrams and refractory catalogs list periclase bricks as MgO-rich, often with spinel (MgAl2O4) additions for improved thermal shock.
Why Other Options Are Wrong:
- CaO: lime; relevant for doloma but not periclase.
- Al2O3/SiO2/ZrO2: define other refractory families.
Common Pitfalls:Confusing periclase (MgO) with doloma (CaO·MgO) or magnesia-chrome compositions.
Final Answer:MgO