Pyrometric Cone Equivalent (PCE): superduty fireclay refractories have PCE greater than cone 33. This corresponds most closely to which approximate temperature (°C)?

Introduction / Context:
Pyrometric Cone Equivalent (PCE) is a comparative measure of refractoriness indicating the softening behavior of a refractory composition relative to standard Seger (Orton) cones. Superduty fireclay refractories are specified by high PCE values, ensuring they retain shape and strength at elevated service temperatures.

Given Data / Assumptions:

• Superduty category defined by PCE > cone 33.
• We seek the approximate equivalent temperature for cone 33 on standard charts.
• Reference temperatures are approximate and depend on heating rate and method, but widely tabulated.

Concept / Approach:
Standard tables correlate cone numbers with equivalent temperatures under specified heating schedules. Cone 33 corresponds roughly to 1730 °C. Therefore, a refractory rating of “PCE > 33” indicates softening above ~1730 °C, consistent with the superduty class expected for demanding furnace zones and coke-oven service.

Step-by-Step Solution:

Verification / Alternative check:
Multiple handbooks list cone 33 near 1730 °C; neighboring cones (e.g., 32 ~ 1710 °C, 34 ~ 1750 °C) bracket this value, confirming the selection.

Why Other Options Are Wrong:

• 1520–1670 °C: too low for cone 33, representing lower cone numbers.
• 1850 °C: exceeds typical cone 34–36 mapping; not the standard equivalence for 33.

Common Pitfalls:
Confusing PCE with service temperature (which may be lower due to load/chemical attack); ignoring heating rate dependence of cone equivalence.

Final Answer:
1730 °C