Pyrometric Cone Equivalent (PCE): For a ‘‘superduty’’ refractory (Seger cone number > 33), the corresponding temperature is closest to which value (°C)?

Introduction / Context:
Pyrometric Cone Equivalent (PCE), often expressed via Seger cone numbers, provides a comparative measure of refractoriness under a standardized heating schedule. Classification into duty classes (e.g., superduty) guides selection for severe high-temperature service such as coke ovens, glass tanks, and steel furnaces.

Given Data / Assumptions:

• ‘‘Superduty’’ is defined as PCE greater than 33.
• We use standard cone–temperature correlations for oxidizing conditions.
• We select the temperature that best represents cone > 33.

Concept / Approach:
Seger cone numbers map to characteristic softening temperatures. For superduty refractories (cone > 33), the corresponding temperature is above about 1730°C. This class exhibits maximal refractoriness among common silica/aluminosilicate compositions used industrially.

Step-by-Step Solution:

Verification / Alternative check:
Manufacturer datasheets and standards cite PCE grades with approximate equivalent temperatures; superduty aligns with ≳ 1730°C, validating the selection.

Why Other Options Are Wrong:

• 1520, 1630, 1670°C: These correspond to lower cone numbers and do not meet the superduty threshold.

Common Pitfalls:
Confusing PCE with simple fusion point; PCE reflects a softening behavior under load and a heating schedule, not just a single-point melting temperature.

Final Answer:
1730