What is the maximum achievable alumina concentration in high-alumina refractories, reaching up to _____________ percent?
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Answer: D. 90
Explanation
Advanced manufacturing techniques allow premium high-alumina refractory formulations to achieve very high purity levels. Alumina concentration in these top-tier engineering ceramic bricks can reach up to ninety percent. Higher alumina content directly increases the material refractoriness and resistance to chemical attack. High-alumina refractories are classified based on their total aluminum oxide content ranging from fifty to ninety percent. Raw materials like bauxite and tabular alumina provide the high aluminum oxide concentrations required. Increasing alumina forms more stable mullite and corundum crystal phases within the brick matrix.
Glass-melting furnaces and petrochemical reactors utilize high-purity alumina bricks for extreme durability. Extreme operating environments demand high-alumina compositions to prevent premature refractory dissolution. Understanding alumina grading helps engineers select appropriate materials for severe industrial service. Thirty percent alumina describes standard fireclay rather than high-alumina refractory grades. Fifty percent represents intermediate high-alumina bricks rather than the maximum achievable concentration. Seventy percent is common for high-duty bricks but falls short of the ninety percent maximum limit.
- Subject
- Engineering
- Category
- Chemical Engineering
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- —
- Difficulty
- medium
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